Adding upstream version 15.5.upstream/15.5

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 19402 insertions, 0 deletions

diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
new file mode 100644
index 0000000..97f9a22
--- /dev/null
+++ b/src/backend/commands/tablecmds.c
@@ -0,0 +1,19402 @@
+/*-------------------------------------------------------------------------
+ *
+ * tablecmds.c
+ *	  Commands for creating and altering table structures and settings
+ *
+ * Portions Copyright (c) 1996-2022, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/commands/tablecmds.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "access/attmap.h"
+#include "access/genam.h"
+#include "access/heapam.h"
+#include "access/heapam_xlog.h"
+#include "access/multixact.h"
+#include "access/reloptions.h"
+#include "access/relscan.h"
+#include "access/sysattr.h"
+#include "access/tableam.h"
+#include "access/toast_compression.h"
+#include "access/xact.h"
+#include "access/xlog.h"
+#include "access/xloginsert.h"
+#include "catalog/catalog.h"
+#include "catalog/heap.h"
+#include "catalog/index.h"
+#include "catalog/namespace.h"
+#include "catalog/objectaccess.h"
+#include "catalog/partition.h"
+#include "catalog/pg_am.h"
+#include "catalog/pg_attrdef.h"
+#include "catalog/pg_collation.h"
+#include "catalog/pg_constraint.h"
+#include "catalog/pg_depend.h"
+#include "catalog/pg_foreign_table.h"
+#include "catalog/pg_inherits.h"
+#include "catalog/pg_largeobject.h"
+#include "catalog/pg_namespace.h"
+#include "catalog/pg_opclass.h"
+#include "catalog/pg_statistic_ext.h"
+#include "catalog/pg_tablespace.h"
+#include "catalog/pg_trigger.h"
+#include "catalog/pg_type.h"
+#include "catalog/storage.h"
+#include "catalog/storage_xlog.h"
+#include "catalog/toasting.h"
+#include "commands/cluster.h"
+#include "commands/comment.h"
+#include "commands/defrem.h"
+#include "commands/event_trigger.h"
+#include "commands/policy.h"
+#include "commands/sequence.h"
+#include "commands/tablecmds.h"
+#include "commands/tablespace.h"
+#include "commands/trigger.h"
+#include "commands/typecmds.h"
+#include "commands/user.h"
+#include "executor/executor.h"
+#include "foreign/fdwapi.h"
+#include "foreign/foreign.h"
+#include "miscadmin.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/parsenodes.h"
+#include "optimizer/optimizer.h"
+#include "parser/parse_clause.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_collate.h"
+#include "parser/parse_expr.h"
+#include "parser/parse_oper.h"
+#include "parser/parse_relation.h"
+#include "parser/parse_type.h"
+#include "parser/parse_utilcmd.h"
+#include "parser/parser.h"
+#include "partitioning/partbounds.h"
+#include "partitioning/partdesc.h"
+#include "pgstat.h"
+#include "rewrite/rewriteDefine.h"
+#include "rewrite/rewriteHandler.h"
+#include "rewrite/rewriteManip.h"
+#include "storage/bufmgr.h"
+#include "storage/lmgr.h"
+#include "storage/lock.h"
+#include "storage/predicate.h"
+#include "storage/smgr.h"
+#include "tcop/utility.h"
+#include "utils/acl.h"
+#include "utils/builtins.h"
+#include "utils/fmgroids.h"
+#include "utils/inval.h"
+#include "utils/lsyscache.h"
+#include "utils/memutils.h"
+#include "utils/partcache.h"
+#include "utils/relcache.h"
+#include "utils/ruleutils.h"
+#include "utils/snapmgr.h"
+#include "utils/syscache.h"
+#include "utils/timestamp.h"
+#include "utils/typcache.h"
+
+/*
+ * ON COMMIT action list
+ */
+typedef struct OnCommitItem
+{
+	Oid			relid;			/* relid of relation */
+	OnCommitAction oncommit;	/* what to do at end of xact */
+
+	/*
+	 * If this entry was created during the current transaction,
+	 * creating_subid is the ID of the creating subxact; if created in a prior
+	 * transaction, creating_subid is zero.  If deleted during the current
+	 * transaction, deleting_subid is the ID of the deleting subxact; if no
+	 * deletion request is pending, deleting_subid is zero.
+	 */
+	SubTransactionId creating_subid;
+	SubTransactionId deleting_subid;
+} OnCommitItem;
+
+static List *on_commits = NIL;
+
+
+/*
+ * State information for ALTER TABLE
+ *
+ * The pending-work queue for an ALTER TABLE is a List of AlteredTableInfo
+ * structs, one for each table modified by the operation (the named table
+ * plus any child tables that are affected).  We save lists of subcommands
+ * to apply to this table (possibly modified by parse transformation steps);
+ * these lists will be executed in Phase 2.  If a Phase 3 step is needed,
+ * necessary information is stored in the constraints and newvals lists.
+ *
+ * Phase 2 is divided into multiple passes; subcommands are executed in
+ * a pass determined by subcommand type.
+ */
+
+#define AT_PASS_UNSET			-1	/* UNSET will cause ERROR */
+#define AT_PASS_DROP			0	/* DROP (all flavors) */
+#define AT_PASS_ALTER_TYPE		1	/* ALTER COLUMN TYPE */
+#define AT_PASS_OLD_INDEX		2	/* re-add existing indexes */
+#define AT_PASS_OLD_CONSTR		3	/* re-add existing constraints */
+/* We could support a RENAME COLUMN pass here, but not currently used */
+#define AT_PASS_ADD_COL			4	/* ADD COLUMN */
+#define AT_PASS_ADD_CONSTR		5	/* ADD constraints (initial examination) */
+#define AT_PASS_COL_ATTRS		6	/* set column attributes, eg NOT NULL */
+#define AT_PASS_ADD_INDEXCONSTR	7	/* ADD index-based constraints */
+#define AT_PASS_ADD_INDEX		8	/* ADD indexes */
+#define AT_PASS_ADD_OTHERCONSTR	9	/* ADD other constraints, defaults */
+#define AT_PASS_MISC			10	/* other stuff */
+#define AT_NUM_PASSES			11
+
+typedef struct AlteredTableInfo
+{
+	/* Information saved before any work commences: */
+	Oid			relid;			/* Relation to work on */
+	char		relkind;		/* Its relkind */
+	TupleDesc	oldDesc;		/* Pre-modification tuple descriptor */
+
+	/*
+	 * Transiently set during Phase 2, normally set to NULL.
+	 *
+	 * ATRewriteCatalogs sets this when it starts, and closes when ATExecCmd
+	 * returns control.  This can be exploited by ATExecCmd subroutines to
+	 * close/reopen across transaction boundaries.
+	 */
+	Relation	rel;
+
+	/* Information saved by Phase 1 for Phase 2: */
+	List	   *subcmds[AT_NUM_PASSES]; /* Lists of AlterTableCmd */
+	/* Information saved by Phases 1/2 for Phase 3: */
+	List	   *constraints;	/* List of NewConstraint */
+	List	   *newvals;		/* List of NewColumnValue */
+	List	   *afterStmts;		/* List of utility command parsetrees */
+	bool		verify_new_notnull; /* T if we should recheck NOT NULL */
+	int			rewrite;		/* Reason for forced rewrite, if any */
+	Oid			newAccessMethod;	/* new access method; 0 means no change */
+	Oid			newTableSpace;	/* new tablespace; 0 means no change */
+	bool		chgPersistence; /* T if SET LOGGED/UNLOGGED is used */
+	char		newrelpersistence;	/* if above is true */
+	Expr	   *partition_constraint;	/* for attach partition validation */
+	/* true, if validating default due to some other attach/detach */
+	bool		validate_default;
+	/* Objects to rebuild after completing ALTER TYPE operations */
+	List	   *changedConstraintOids;	/* OIDs of constraints to rebuild */
+	List	   *changedConstraintDefs;	/* string definitions of same */
+	List	   *changedIndexOids;	/* OIDs of indexes to rebuild */
+	List	   *changedIndexDefs;	/* string definitions of same */
+	char	   *replicaIdentityIndex;	/* index to reset as REPLICA IDENTITY */
+	char	   *clusterOnIndex; /* index to use for CLUSTER */
+	List	   *changedStatisticsOids;	/* OIDs of statistics to rebuild */
+	List	   *changedStatisticsDefs;	/* string definitions of same */
+} AlteredTableInfo;
+
+/* Struct describing one new constraint to check in Phase 3 scan */
+/* Note: new NOT NULL constraints are handled elsewhere */
+typedef struct NewConstraint
+{
+	char	   *name;			/* Constraint name, or NULL if none */
+	ConstrType	contype;		/* CHECK or FOREIGN */
+	Oid			refrelid;		/* PK rel, if FOREIGN */
+	Oid			refindid;		/* OID of PK's index, if FOREIGN */
+	Oid			conid;			/* OID of pg_constraint entry, if FOREIGN */
+	Node	   *qual;			/* Check expr or CONSTR_FOREIGN Constraint */
+	ExprState  *qualstate;		/* Execution state for CHECK expr */
+} NewConstraint;
+
+/*
+ * Struct describing one new column value that needs to be computed during
+ * Phase 3 copy (this could be either a new column with a non-null default, or
+ * a column that we're changing the type of).  Columns without such an entry
+ * are just copied from the old table during ATRewriteTable.  Note that the
+ * expr is an expression over *old* table values, except when is_generated
+ * is true; then it is an expression over columns of the *new* tuple.
+ */
+typedef struct NewColumnValue
+{
+	AttrNumber	attnum;			/* which column */
+	Expr	   *expr;			/* expression to compute */
+	ExprState  *exprstate;		/* execution state */
+	bool		is_generated;	/* is it a GENERATED expression? */
+} NewColumnValue;
+
+/*
+ * Error-reporting support for RemoveRelations
+ */
+struct dropmsgstrings
+{
+	char		kind;
+	int			nonexistent_code;
+	const char *nonexistent_msg;
+	const char *skipping_msg;
+	const char *nota_msg;
+	const char *drophint_msg;
+};
+
+static const struct dropmsgstrings dropmsgstringarray[] = {
+	{RELKIND_RELATION,
+		ERRCODE_UNDEFINED_TABLE,
+		gettext_noop("table \"%s\" does not exist"),
+		gettext_noop("table \"%s\" does not exist, skipping"),
+		gettext_noop("\"%s\" is not a table"),
+	gettext_noop("Use DROP TABLE to remove a table.")},
+	{RELKIND_SEQUENCE,
+		ERRCODE_UNDEFINED_TABLE,
+		gettext_noop("sequence \"%s\" does not exist"),
+		gettext_noop("sequence \"%s\" does not exist, skipping"),
+		gettext_noop("\"%s\" is not a sequence"),
+	gettext_noop("Use DROP SEQUENCE to remove a sequence.")},
+	{RELKIND_VIEW,
+		ERRCODE_UNDEFINED_TABLE,
+		gettext_noop("view \"%s\" does not exist"),
+		gettext_noop("view \"%s\" does not exist, skipping"),
+		gettext_noop("\"%s\" is not a view"),
+	gettext_noop("Use DROP VIEW to remove a view.")},
+	{RELKIND_MATVIEW,
+		ERRCODE_UNDEFINED_TABLE,
+		gettext_noop("materialized view \"%s\" does not exist"),
+		gettext_noop("materialized view \"%s\" does not exist, skipping"),
+		gettext_noop("\"%s\" is not a materialized view"),
+	gettext_noop("Use DROP MATERIALIZED VIEW to remove a materialized view.")},
+	{RELKIND_INDEX,
+		ERRCODE_UNDEFINED_OBJECT,
+		gettext_noop("index \"%s\" does not exist"),
+		gettext_noop("index \"%s\" does not exist, skipping"),
+		gettext_noop("\"%s\" is not an index"),
+	gettext_noop("Use DROP INDEX to remove an index.")},
+	{RELKIND_COMPOSITE_TYPE,
+		ERRCODE_UNDEFINED_OBJECT,
+		gettext_noop("type \"%s\" does not exist"),
+		gettext_noop("type \"%s\" does not exist, skipping"),
+		gettext_noop("\"%s\" is not a type"),
+	gettext_noop("Use DROP TYPE to remove a type.")},
+	{RELKIND_FOREIGN_TABLE,
+		ERRCODE_UNDEFINED_OBJECT,
+		gettext_noop("foreign table \"%s\" does not exist"),
+		gettext_noop("foreign table \"%s\" does not exist, skipping"),
+		gettext_noop("\"%s\" is not a foreign table"),
+	gettext_noop("Use DROP FOREIGN TABLE to remove a foreign table.")},
+	{RELKIND_PARTITIONED_TABLE,
+		ERRCODE_UNDEFINED_TABLE,
+		gettext_noop("table \"%s\" does not exist"),
+		gettext_noop("table \"%s\" does not exist, skipping"),
+		gettext_noop("\"%s\" is not a table"),
+	gettext_noop("Use DROP TABLE to remove a table.")},
+	{RELKIND_PARTITIONED_INDEX,
+		ERRCODE_UNDEFINED_OBJECT,
+		gettext_noop("index \"%s\" does not exist"),
+		gettext_noop("index \"%s\" does not exist, skipping"),
+		gettext_noop("\"%s\" is not an index"),
+	gettext_noop("Use DROP INDEX to remove an index.")},
+	{'\0', 0, NULL, NULL, NULL, NULL}
+};
+
+/* communication between RemoveRelations and RangeVarCallbackForDropRelation */
+struct DropRelationCallbackState
+{
+	/* These fields are set by RemoveRelations: */
+	char		expected_relkind;
+	LOCKMODE	heap_lockmode;
+	/* These fields are state to track which subsidiary locks are held: */
+	Oid			heapOid;
+	Oid			partParentOid;
+	/* These fields are passed back by RangeVarCallbackForDropRelation: */
+	char		actual_relkind;
+	char		actual_relpersistence;
+};
+
+/* Alter table target-type flags for ATSimplePermissions */
+#define		ATT_TABLE				0x0001
+#define		ATT_VIEW				0x0002
+#define		ATT_MATVIEW				0x0004
+#define		ATT_INDEX				0x0008
+#define		ATT_COMPOSITE_TYPE		0x0010
+#define		ATT_FOREIGN_TABLE		0x0020
+#define		ATT_PARTITIONED_INDEX	0x0040
+#define		ATT_SEQUENCE			0x0080
+
+/*
+ * ForeignTruncateInfo
+ *
+ * Information related to truncation of foreign tables.  This is used for
+ * the elements in a hash table. It uses the server OID as lookup key,
+ * and includes a per-server list of all foreign tables involved in the
+ * truncation.
+ */
+typedef struct ForeignTruncateInfo
+{
+	Oid			serverid;
+	List	   *rels;
+} ForeignTruncateInfo;
+
+/*
+ * Partition tables are expected to be dropped when the parent partitioned
+ * table gets dropped. Hence for partitioning we use AUTO dependency.
+ * Otherwise, for regular inheritance use NORMAL dependency.
+ */
+#define child_dependency_type(child_is_partition)	\
+	((child_is_partition) ? DEPENDENCY_AUTO : DEPENDENCY_NORMAL)
+
+static void truncate_check_rel(Oid relid, Form_pg_class reltuple);
+static void truncate_check_perms(Oid relid, Form_pg_class reltuple);
+static void truncate_check_activity(Relation rel);
+static void RangeVarCallbackForTruncate(const RangeVar *relation,
+										Oid relId, Oid oldRelId, void *arg);
+static List *MergeAttributes(List *schema, List *supers, char relpersistence,
+							 bool is_partition, List **supconstr);
+static bool MergeCheckConstraint(List *constraints, char *name, Node *expr);
+static void MergeAttributesIntoExisting(Relation child_rel, Relation parent_rel);
+static void MergeConstraintsIntoExisting(Relation child_rel, Relation parent_rel);
+static void StoreCatalogInheritance(Oid relationId, List *supers,
+									bool child_is_partition);
+static void StoreCatalogInheritance1(Oid relationId, Oid parentOid,
+									 int32 seqNumber, Relation inhRelation,
+									 bool child_is_partition);
+static int	findAttrByName(const char *attributeName, List *schema);
+static void AlterIndexNamespaces(Relation classRel, Relation rel,
+								 Oid oldNspOid, Oid newNspOid, ObjectAddresses *objsMoved);
+static void AlterSeqNamespaces(Relation classRel, Relation rel,
+							   Oid oldNspOid, Oid newNspOid, ObjectAddresses *objsMoved,
+							   LOCKMODE lockmode);
+static ObjectAddress ATExecAlterConstraint(Relation rel, AlterTableCmd *cmd,
+										   bool recurse, bool recursing, LOCKMODE lockmode);
+static bool ATExecAlterConstrRecurse(Constraint *cmdcon, Relation conrel, Relation tgrel,
+									 Relation rel, HeapTuple contuple, List **otherrelids,
+									 LOCKMODE lockmode);
+static ObjectAddress ATExecValidateConstraint(List **wqueue,
+											  Relation rel, char *constrName,
+											  bool recurse, bool recursing, LOCKMODE lockmode);
+static int	transformColumnNameList(Oid relId, List *colList,
+									int16 *attnums, Oid *atttypids);
+static int	transformFkeyGetPrimaryKey(Relation pkrel, Oid *indexOid,
+									   List **attnamelist,
+									   int16 *attnums, Oid *atttypids,
+									   Oid *opclasses);
+static Oid	transformFkeyCheckAttrs(Relation pkrel,
+									int numattrs, int16 *attnums,
+									Oid *opclasses);
+static void checkFkeyPermissions(Relation rel, int16 *attnums, int natts);
+static CoercionPathType findFkeyCast(Oid targetTypeId, Oid sourceTypeId,
+									 Oid *funcid);
+static void validateForeignKeyConstraint(char *conname,
+										 Relation rel, Relation pkrel,
+										 Oid pkindOid, Oid constraintOid);
+static void ATController(AlterTableStmt *parsetree,
+						 Relation rel, List *cmds, bool recurse, LOCKMODE lockmode,
+						 AlterTableUtilityContext *context);
+static void ATPrepCmd(List **wqueue, Relation rel, AlterTableCmd *cmd,
+					  bool recurse, bool recursing, LOCKMODE lockmode,
+					  AlterTableUtilityContext *context);
+static void ATRewriteCatalogs(List **wqueue, LOCKMODE lockmode,
+							  AlterTableUtilityContext *context);
+static void ATExecCmd(List **wqueue, AlteredTableInfo *tab,
+					  AlterTableCmd *cmd, LOCKMODE lockmode, int cur_pass,
+					  AlterTableUtilityContext *context);
+static AlterTableCmd *ATParseTransformCmd(List **wqueue, AlteredTableInfo *tab,
+										  Relation rel, AlterTableCmd *cmd,
+										  bool recurse, LOCKMODE lockmode,
+										  int cur_pass,
+										  AlterTableUtilityContext *context);
+static void ATRewriteTables(AlterTableStmt *parsetree,
+							List **wqueue, LOCKMODE lockmode,
+							AlterTableUtilityContext *context);
+static void ATRewriteTable(AlteredTableInfo *tab, Oid OIDNewHeap, LOCKMODE lockmode);
+static AlteredTableInfo *ATGetQueueEntry(List **wqueue, Relation rel);
+static void ATSimplePermissions(AlterTableType cmdtype, Relation rel, int allowed_targets);
+static void ATSimpleRecursion(List **wqueue, Relation rel,
+							  AlterTableCmd *cmd, bool recurse, LOCKMODE lockmode,
+							  AlterTableUtilityContext *context);
+static void ATCheckPartitionsNotInUse(Relation rel, LOCKMODE lockmode);
+static void ATTypedTableRecursion(List **wqueue, Relation rel, AlterTableCmd *cmd,
+								  LOCKMODE lockmode,
+								  AlterTableUtilityContext *context);
+static List *find_typed_table_dependencies(Oid typeOid, const char *typeName,
+										   DropBehavior behavior);
+static void ATPrepAddColumn(List **wqueue, Relation rel, bool recurse, bool recursing,
+							bool is_view, AlterTableCmd *cmd, LOCKMODE lockmode,
+							AlterTableUtilityContext *context);
+static ObjectAddress ATExecAddColumn(List **wqueue, AlteredTableInfo *tab,
+									 Relation rel, AlterTableCmd **cmd,
+									 bool recurse, bool recursing,
+									 LOCKMODE lockmode, int cur_pass,
+									 AlterTableUtilityContext *context);
+static bool check_for_column_name_collision(Relation rel, const char *colname,
+											bool if_not_exists);
+static void add_column_datatype_dependency(Oid relid, int32 attnum, Oid typid);
+static void add_column_collation_dependency(Oid relid, int32 attnum, Oid collid);
+static void ATPrepDropNotNull(Relation rel, bool recurse, bool recursing);
+static ObjectAddress ATExecDropNotNull(Relation rel, const char *colName, LOCKMODE lockmode);
+static void ATPrepSetNotNull(List **wqueue, Relation rel,
+							 AlterTableCmd *cmd, bool recurse, bool recursing,
+							 LOCKMODE lockmode,
+							 AlterTableUtilityContext *context);
+static ObjectAddress ATExecSetNotNull(AlteredTableInfo *tab, Relation rel,
+									  const char *colName, LOCKMODE lockmode);
+static void ATExecCheckNotNull(AlteredTableInfo *tab, Relation rel,
+							   const char *colName, LOCKMODE lockmode);
+static bool NotNullImpliedByRelConstraints(Relation rel, Form_pg_attribute attr);
+static bool ConstraintImpliedByRelConstraint(Relation scanrel,
+											 List *testConstraint, List *provenConstraint);
+static ObjectAddress ATExecColumnDefault(Relation rel, const char *colName,
+										 Node *newDefault, LOCKMODE lockmode);
+static ObjectAddress ATExecCookedColumnDefault(Relation rel, AttrNumber attnum,
+											   Node *newDefault);
+static ObjectAddress ATExecAddIdentity(Relation rel, const char *colName,
+									   Node *def, LOCKMODE lockmode);
+static ObjectAddress ATExecSetIdentity(Relation rel, const char *colName,
+									   Node *def, LOCKMODE lockmode);
+static ObjectAddress ATExecDropIdentity(Relation rel, const char *colName, bool missing_ok, LOCKMODE lockmode);
+static void ATPrepDropExpression(Relation rel, AlterTableCmd *cmd, bool recurse, bool recursing, LOCKMODE lockmode);
+static ObjectAddress ATExecDropExpression(Relation rel, const char *colName, bool missing_ok, LOCKMODE lockmode);
+static ObjectAddress ATExecSetStatistics(Relation rel, const char *colName, int16 colNum,
+										 Node *newValue, LOCKMODE lockmode);
+static ObjectAddress ATExecSetOptions(Relation rel, const char *colName,
+									  Node *options, bool isReset, LOCKMODE lockmode);
+static ObjectAddress ATExecSetStorage(Relation rel, const char *colName,
+									  Node *newValue, LOCKMODE lockmode);
+static void ATPrepDropColumn(List **wqueue, Relation rel, bool recurse, bool recursing,
+							 AlterTableCmd *cmd, LOCKMODE lockmode,
+							 AlterTableUtilityContext *context);
+static ObjectAddress ATExecDropColumn(List **wqueue, Relation rel, const char *colName,
+									  DropBehavior behavior,
+									  bool recurse, bool recursing,
+									  bool missing_ok, LOCKMODE lockmode,
+									  ObjectAddresses *addrs);
+static ObjectAddress ATExecAddIndex(AlteredTableInfo *tab, Relation rel,
+									IndexStmt *stmt, bool is_rebuild, LOCKMODE lockmode);
+static ObjectAddress ATExecAddStatistics(AlteredTableInfo *tab, Relation rel,
+										 CreateStatsStmt *stmt, bool is_rebuild, LOCKMODE lockmode);
+static ObjectAddress ATExecAddConstraint(List **wqueue,
+										 AlteredTableInfo *tab, Relation rel,
+										 Constraint *newConstraint, bool recurse, bool is_readd,
+										 LOCKMODE lockmode);
+static char *ChooseForeignKeyConstraintNameAddition(List *colnames);
+static ObjectAddress ATExecAddIndexConstraint(AlteredTableInfo *tab, Relation rel,
+											  IndexStmt *stmt, LOCKMODE lockmode);
+static ObjectAddress ATAddCheckConstraint(List **wqueue,
+										  AlteredTableInfo *tab, Relation rel,
+										  Constraint *constr,
+										  bool recurse, bool recursing, bool is_readd,
+										  LOCKMODE lockmode);
+static ObjectAddress ATAddForeignKeyConstraint(List **wqueue, AlteredTableInfo *tab,
+											   Relation rel, Constraint *fkconstraint,
+											   bool recurse, bool recursing,
+											   LOCKMODE lockmode);
+static ObjectAddress addFkRecurseReferenced(List **wqueue, Constraint *fkconstraint,
+											Relation rel, Relation pkrel, Oid indexOid, Oid parentConstr,
+											int numfks, int16 *pkattnum, int16 *fkattnum,
+											Oid *pfeqoperators, Oid *ppeqoperators, Oid *ffeqoperators,
+											int numfkdelsetcols, int16 *fkdelsetcols,
+											bool old_check_ok,
+											Oid parentDelTrigger, Oid parentUpdTrigger);
+static void validateFkOnDeleteSetColumns(int numfks, const int16 *fkattnums,
+										 int numfksetcols, const int16 *fksetcolsattnums,
+										 List *fksetcols);
+static void addFkRecurseReferencing(List **wqueue, Constraint *fkconstraint,
+									Relation rel, Relation pkrel, Oid indexOid, Oid parentConstr,
+									int numfks, int16 *pkattnum, int16 *fkattnum,
+									Oid *pfeqoperators, Oid *ppeqoperators, Oid *ffeqoperators,
+									int numfkdelsetcols, int16 *fkdelsetcols,
+									bool old_check_ok, LOCKMODE lockmode,
+									Oid parentInsTrigger, Oid parentUpdTrigger);
+static void CloneForeignKeyConstraints(List **wqueue, Relation parentRel,
+									   Relation partitionRel);
+static void CloneFkReferenced(Relation parentRel, Relation partitionRel);
+static void CloneFkReferencing(List **wqueue, Relation parentRel,
+							   Relation partRel);
+static void createForeignKeyCheckTriggers(Oid myRelOid, Oid refRelOid,
+										  Constraint *fkconstraint, Oid constraintOid,
+										  Oid indexOid,
+										  Oid parentInsTrigger, Oid parentUpdTrigger,
+										  Oid *insertTrigOid, Oid *updateTrigOid);
+static void createForeignKeyActionTriggers(Relation rel, Oid refRelOid,
+										   Constraint *fkconstraint, Oid constraintOid,
+										   Oid indexOid,
+										   Oid parentDelTrigger, Oid parentUpdTrigger,
+										   Oid *deleteTrigOid, Oid *updateTrigOid);
+static bool tryAttachPartitionForeignKey(ForeignKeyCacheInfo *fk,
+										 Oid partRelid,
+										 Oid parentConstrOid, int numfks,
+										 AttrNumber *mapped_conkey, AttrNumber *confkey,
+										 Oid *conpfeqop,
+										 Oid parentInsTrigger,
+										 Oid parentUpdTrigger,
+										 Relation trigrel);
+static void GetForeignKeyActionTriggers(Relation trigrel,
+										Oid conoid, Oid confrelid, Oid conrelid,
+										Oid *deleteTriggerOid,
+										Oid *updateTriggerOid);
+static void GetForeignKeyCheckTriggers(Relation trigrel,
+									   Oid conoid, Oid confrelid, Oid conrelid,
+									   Oid *insertTriggerOid,
+									   Oid *updateTriggerOid);
+static void ATExecDropConstraint(Relation rel, const char *constrName,
+								 DropBehavior behavior,
+								 bool recurse, bool recursing,
+								 bool missing_ok, LOCKMODE lockmode);
+static void ATPrepAlterColumnType(List **wqueue,
+								  AlteredTableInfo *tab, Relation rel,
+								  bool recurse, bool recursing,
+								  AlterTableCmd *cmd, LOCKMODE lockmode,
+								  AlterTableUtilityContext *context);
+static bool ATColumnChangeRequiresRewrite(Node *expr, AttrNumber varattno);
+static ObjectAddress ATExecAlterColumnType(AlteredTableInfo *tab, Relation rel,
+										   AlterTableCmd *cmd, LOCKMODE lockmode);
+static void RememberConstraintForRebuilding(Oid conoid, AlteredTableInfo *tab);
+static void RememberIndexForRebuilding(Oid indoid, AlteredTableInfo *tab);
+static void RememberStatisticsForRebuilding(Oid indoid, AlteredTableInfo *tab);
+static void ATPostAlterTypeCleanup(List **wqueue, AlteredTableInfo *tab,
+								   LOCKMODE lockmode);
+static void ATPostAlterTypeParse(Oid oldId, Oid oldRelId, Oid refRelId,
+								 char *cmd, List **wqueue, LOCKMODE lockmode,
+								 bool rewrite);
+static void RebuildConstraintComment(AlteredTableInfo *tab, int pass,
+									 Oid objid, Relation rel, List *domname,
+									 const char *conname);
+static void TryReuseIndex(Oid oldId, IndexStmt *stmt);
+static void TryReuseForeignKey(Oid oldId, Constraint *con);
+static ObjectAddress ATExecAlterColumnGenericOptions(Relation rel, const char *colName,
+													 List *options, LOCKMODE lockmode);
+static void change_owner_fix_column_acls(Oid relationOid,
+										 Oid oldOwnerId, Oid newOwnerId);
+static void change_owner_recurse_to_sequences(Oid relationOid,
+											  Oid newOwnerId, LOCKMODE lockmode);
+static ObjectAddress ATExecClusterOn(Relation rel, const char *indexName,
+									 LOCKMODE lockmode);
+static void ATExecDropCluster(Relation rel, LOCKMODE lockmode);
+static void ATPrepSetAccessMethod(AlteredTableInfo *tab, Relation rel, const char *amname);
+static bool ATPrepChangePersistence(Relation rel, bool toLogged);
+static void ATPrepSetTableSpace(AlteredTableInfo *tab, Relation rel,
+								const char *tablespacename, LOCKMODE lockmode);
+static void ATExecSetTableSpace(Oid tableOid, Oid newTableSpace, LOCKMODE lockmode);
+static void ATExecSetTableSpaceNoStorage(Relation rel, Oid newTableSpace);
+static void ATExecSetRelOptions(Relation rel, List *defList,
+								AlterTableType operation,
+								LOCKMODE lockmode);
+static void ATExecEnableDisableTrigger(Relation rel, const char *trigname,
+									   char fires_when, bool skip_system, bool recurse,
+									   LOCKMODE lockmode);
+static void ATExecEnableDisableRule(Relation rel, const char *rulename,
+									char fires_when, LOCKMODE lockmode);
+static void ATPrepAddInherit(Relation child_rel);
+static ObjectAddress ATExecAddInherit(Relation child_rel, RangeVar *parent, LOCKMODE lockmode);
+static ObjectAddress ATExecDropInherit(Relation rel, RangeVar *parent, LOCKMODE lockmode);
+static void drop_parent_dependency(Oid relid, Oid refclassid, Oid refobjid,
+								   DependencyType deptype);
+static ObjectAddress ATExecAddOf(Relation rel, const TypeName *ofTypename, LOCKMODE lockmode);
+static void ATExecDropOf(Relation rel, LOCKMODE lockmode);
+static void ATExecReplicaIdentity(Relation rel, ReplicaIdentityStmt *stmt, LOCKMODE lockmode);
+static void ATExecGenericOptions(Relation rel, List *options);
+static void ATExecSetRowSecurity(Relation rel, bool rls);
+static void ATExecForceNoForceRowSecurity(Relation rel, bool force_rls);
+static ObjectAddress ATExecSetCompression(AlteredTableInfo *tab, Relation rel,
+										  const char *column, Node *newValue, LOCKMODE lockmode);
+
+static void index_copy_data(Relation rel, RelFileNode newrnode);
+static const char *storage_name(char c);
+
+static void RangeVarCallbackForDropRelation(const RangeVar *rel, Oid relOid,
+											Oid oldRelOid, void *arg);
+static void RangeVarCallbackForAlterRelation(const RangeVar *rv, Oid relid,
+											 Oid oldrelid, void *arg);
+static PartitionSpec *transformPartitionSpec(Relation rel, PartitionSpec *partspec, char *strategy);
+static void ComputePartitionAttrs(ParseState *pstate, Relation rel, List *partParams, AttrNumber *partattrs,
+								  List **partexprs, Oid *partopclass, Oid *partcollation, char strategy);
+static void CreateInheritance(Relation child_rel, Relation parent_rel);
+static void RemoveInheritance(Relation child_rel, Relation parent_rel,
+							  bool allow_detached);
+static ObjectAddress ATExecAttachPartition(List **wqueue, Relation rel,
+										   PartitionCmd *cmd,
+										   AlterTableUtilityContext *context);
+static void AttachPartitionEnsureIndexes(Relation rel, Relation attachrel);
+static void QueuePartitionConstraintValidation(List **wqueue, Relation scanrel,
+											   List *partConstraint,
+											   bool validate_default);
+static void CloneRowTriggersToPartition(Relation parent, Relation partition);
+static void DetachAddConstraintIfNeeded(List **wqueue, Relation partRel);
+static void DropClonedTriggersFromPartition(Oid partitionId);
+static ObjectAddress ATExecDetachPartition(List **wqueue, AlteredTableInfo *tab,
+										   Relation rel, RangeVar *name,
+										   bool concurrent);
+static void DetachPartitionFinalize(Relation rel, Relation partRel,
+									bool concurrent, Oid defaultPartOid);
+static ObjectAddress ATExecDetachPartitionFinalize(Relation rel, RangeVar *name);
+static ObjectAddress ATExecAttachPartitionIdx(List **wqueue, Relation rel,
+											  RangeVar *name);
+static void validatePartitionedIndex(Relation partedIdx, Relation partedTbl);
+static void refuseDupeIndexAttach(Relation parentIdx, Relation partIdx,
+								  Relation partitionTbl);
+static List *GetParentedForeignKeyRefs(Relation partition);
+static void ATDetachCheckNoForeignKeyRefs(Relation partition);
+static char GetAttributeCompression(Oid atttypid, char *compression);
+
+
+/* ----------------------------------------------------------------
+ *		DefineRelation
+ *				Creates a new relation.
+ *
+ * stmt carries parsetree information from an ordinary CREATE TABLE statement.
+ * The other arguments are used to extend the behavior for other cases:
+ * relkind: relkind to assign to the new relation
+ * ownerId: if not InvalidOid, use this as the new relation's owner.
+ * typaddress: if not null, it's set to the pg_type entry's address.
+ * queryString: for error reporting
+ *
+ * Note that permissions checks are done against current user regardless of
+ * ownerId.  A nonzero ownerId is used when someone is creating a relation
+ * "on behalf of" someone else, so we still want to see that the current user
+ * has permissions to do it.
+ *
+ * If successful, returns the address of the new relation.
+ * ----------------------------------------------------------------
+ */
+ObjectAddress
+DefineRelation(CreateStmt *stmt, char relkind, Oid ownerId,
+			   ObjectAddress *typaddress, const char *queryString)
+{
+	char		relname[NAMEDATALEN];
+	Oid			namespaceId;
+	Oid			relationId;
+	Oid			tablespaceId;
+	Relation	rel;
+	TupleDesc	descriptor;
+	List	   *inheritOids;
+	List	   *old_constraints;
+	List	   *rawDefaults;
+	List	   *cookedDefaults;
+	Datum		reloptions;
+	ListCell   *listptr;
+	AttrNumber	attnum;
+	bool		partitioned;
+	static char *validnsps[] = HEAP_RELOPT_NAMESPACES;
+	Oid			ofTypeId;
+	ObjectAddress address;
+	LOCKMODE	parentLockmode;
+	const char *accessMethod = NULL;
+	Oid			accessMethodId = InvalidOid;
+
+	/*
+	 * Truncate relname to appropriate length (probably a waste of time, as
+	 * parser should have done this already).
+	 */
+	strlcpy(relname, stmt->relation->relname, NAMEDATALEN);
+
+	/*
+	 * Check consistency of arguments
+	 */
+	if (stmt->oncommit != ONCOMMIT_NOOP
+		&& stmt->relation->relpersistence != RELPERSISTENCE_TEMP)
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
+				 errmsg("ON COMMIT can only be used on temporary tables")));
+
+	if (stmt->partspec != NULL)
+	{
+		if (relkind != RELKIND_RELATION)
+			elog(ERROR, "unexpected relkind: %d", (int) relkind);
+
+		relkind = RELKIND_PARTITIONED_TABLE;
+		partitioned = true;
+	}
+	else
+		partitioned = false;
+
+	/*
+	 * Look up the namespace in which we are supposed to create the relation,
+	 * check we have permission to create there, lock it against concurrent
+	 * drop, and mark stmt->relation as RELPERSISTENCE_TEMP if a temporary
+	 * namespace is selected.
+	 */
+	namespaceId =
+		RangeVarGetAndCheckCreationNamespace(stmt->relation, NoLock, NULL);
+
+	/*
+	 * Security check: disallow creating temp tables from security-restricted
+	 * code.  This is needed because calling code might not expect untrusted
+	 * tables to appear in pg_temp at the front of its search path.
+	 */
+	if (stmt->relation->relpersistence == RELPERSISTENCE_TEMP
+		&& InSecurityRestrictedOperation())
+		ereport(ERROR,
+				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
+				 errmsg("cannot create temporary table within security-restricted operation")));
+
+	/*
+	 * Determine the lockmode to use when scanning parents.  A self-exclusive
+	 * lock is needed here.
+	 *
+	 * For regular inheritance, if two backends attempt to add children to the
+	 * same parent simultaneously, and that parent has no pre-existing
+	 * children, then both will attempt to update the parent's relhassubclass
+	 * field, leading to a "tuple concurrently updated" error.  Also, this
+	 * interlocks against a concurrent ANALYZE on the parent table, which
+	 * might otherwise be attempting to clear the parent's relhassubclass
+	 * field, if its previous children were recently dropped.
+	 *
+	 * If the child table is a partition, then we instead grab an exclusive
+	 * lock on the parent because its partition descriptor will be changed by
+	 * addition of the new partition.
+	 */
+	parentLockmode = (stmt->partbound != NULL ? AccessExclusiveLock :
+					  ShareUpdateExclusiveLock);
+
+	/* Determine the list of OIDs of the parents. */
+	inheritOids = NIL;
+	foreach(listptr, stmt->inhRelations)
+	{
+		RangeVar   *rv = (RangeVar *) lfirst(listptr);
+		Oid			parentOid;
+
+		parentOid = RangeVarGetRelid(rv, parentLockmode, false);
+
+		/*
+		 * Reject duplications in the list of parents.
+		 */
+		if (list_member_oid(inheritOids, parentOid))
+			ereport(ERROR,
+					(errcode(ERRCODE_DUPLICATE_TABLE),
+					 errmsg("relation \"%s\" would be inherited from more than once",
+							get_rel_name(parentOid))));
+
+		inheritOids = lappend_oid(inheritOids, parentOid);
+	}
+
+	/*
+	 * Select tablespace to use: an explicitly indicated one, or (in the case
+	 * of a partitioned table) the parent's, if it has one.
+	 */
+	if (stmt->tablespacename)
+	{
+		tablespaceId = get_tablespace_oid(stmt->tablespacename, false);
+
+		if (partitioned && tablespaceId == MyDatabaseTableSpace)
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("cannot specify default tablespace for partitioned relations")));
+	}
+	else if (stmt->partbound)
+	{
+		/*
+		 * For partitions, when no other tablespace is specified, we default
+		 * the tablespace to the parent partitioned table's.
+		 */
+		Assert(list_length(inheritOids) == 1);
+		tablespaceId = get_rel_tablespace(linitial_oid(inheritOids));
+	}
+	else
+		tablespaceId = InvalidOid;
+
+	/* still nothing? use the default */
+	if (!OidIsValid(tablespaceId))
+		tablespaceId = GetDefaultTablespace(stmt->relation->relpersistence,
+											partitioned);
+
+	/* Check permissions except when using database's default */
+	if (OidIsValid(tablespaceId) && tablespaceId != MyDatabaseTableSpace)
+	{
+		AclResult	aclresult;
+
+		aclresult = pg_tablespace_aclcheck(tablespaceId, GetUserId(),
+										   ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tablespaceId));
+	}
+
+	/* In all cases disallow placing user relations in pg_global */
+	if (tablespaceId == GLOBALTABLESPACE_OID)
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("only shared relations can be placed in pg_global tablespace")));
+
+	/* Identify user ID that will own the table */
+	if (!OidIsValid(ownerId))
+		ownerId = GetUserId();
+
+	/*
+	 * Parse and validate reloptions, if any.
+	 */
+	reloptions = transformRelOptions((Datum) 0, stmt->options, NULL, validnsps,
+									 true, false);
+
+	switch (relkind)
+	{
+		case RELKIND_VIEW:
+			(void) view_reloptions(reloptions, true);
+			break;
+		case RELKIND_PARTITIONED_TABLE:
+			(void) partitioned_table_reloptions(reloptions, true);
+			break;
+		default:
+			(void) heap_reloptions(relkind, reloptions, true);
+	}
+
+	if (stmt->ofTypename)
+	{
+		AclResult	aclresult;
+
+		ofTypeId = typenameTypeId(NULL, stmt->ofTypename);
+
+		aclresult = pg_type_aclcheck(ofTypeId, GetUserId(), ACL_USAGE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error_type(aclresult, ofTypeId);
+	}
+	else
+		ofTypeId = InvalidOid;
+
+	/*
+	 * Look up inheritance ancestors and generate relation schema, including
+	 * inherited attributes.  (Note that stmt->tableElts is destructively
+	 * modified by MergeAttributes.)
+	 */
+	stmt->tableElts =
+		MergeAttributes(stmt->tableElts, inheritOids,
+						stmt->relation->relpersistence,
+						stmt->partbound != NULL,
+						&old_constraints);
+
+	/*
+	 * Create a tuple descriptor from the relation schema.  Note that this
+	 * deals with column names, types, and NOT NULL constraints, but not
+	 * default values or CHECK constraints; we handle those below.
+	 */
+	descriptor = BuildDescForRelation(stmt->tableElts);
+
+	/*
+	 * Find columns with default values and prepare for insertion of the
+	 * defaults.  Pre-cooked (that is, inherited) defaults go into a list of
+	 * CookedConstraint structs that we'll pass to heap_create_with_catalog,
+	 * while raw defaults go into a list of RawColumnDefault structs that will
+	 * be processed by AddRelationNewConstraints.  (We can't deal with raw
+	 * expressions until we can do transformExpr.)
+	 *
+	 * We can set the atthasdef flags now in the tuple descriptor; this just
+	 * saves StoreAttrDefault from having to do an immediate update of the
+	 * pg_attribute rows.
+	 */
+	rawDefaults = NIL;
+	cookedDefaults = NIL;
+	attnum = 0;
+
+	foreach(listptr, stmt->tableElts)
+	{
+		ColumnDef  *colDef = lfirst(listptr);
+		Form_pg_attribute attr;
+
+		attnum++;
+		attr = TupleDescAttr(descriptor, attnum - 1);
+
+		if (colDef->raw_default != NULL)
+		{
+			RawColumnDefault *rawEnt;
+
+			Assert(colDef->cooked_default == NULL);
+
+			rawEnt = (RawColumnDefault *) palloc(sizeof(RawColumnDefault));
+			rawEnt->attnum = attnum;
+			rawEnt->raw_default = colDef->raw_default;
+			rawEnt->missingMode = false;
+			rawEnt->generated = colDef->generated;
+			rawDefaults = lappend(rawDefaults, rawEnt);
+			attr->atthasdef = true;
+		}
+		else if (colDef->cooked_default != NULL)
+		{
+			CookedConstraint *cooked;
+
+			cooked = (CookedConstraint *) palloc(sizeof(CookedConstraint));
+			cooked->contype = CONSTR_DEFAULT;
+			cooked->conoid = InvalidOid;	/* until created */
+			cooked->name = NULL;
+			cooked->attnum = attnum;
+			cooked->expr = colDef->cooked_default;
+			cooked->skip_validation = false;
+			cooked->is_local = true;	/* not used for defaults */
+			cooked->inhcount = 0;	/* ditto */
+			cooked->is_no_inherit = false;
+			cookedDefaults = lappend(cookedDefaults, cooked);
+			attr->atthasdef = true;
+		}
+
+		if (colDef->identity)
+			attr->attidentity = colDef->identity;
+
+		if (colDef->generated)
+			attr->attgenerated = colDef->generated;
+
+		if (colDef->compression)
+			attr->attcompression = GetAttributeCompression(attr->atttypid,
+														   colDef->compression);
+	}
+
+	/*
+	 * If the statement hasn't specified an access method, but we're defining
+	 * a type of relation that needs one, use the default.
+	 */
+	if (stmt->accessMethod != NULL)
+	{
+		accessMethod = stmt->accessMethod;
+
+		if (partitioned)
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("specifying a table access method is not supported on a partitioned table")));
+	}
+	else if (RELKIND_HAS_TABLE_AM(relkind))
+		accessMethod = default_table_access_method;
+
+	/* look up the access method, verify it is for a table */
+	if (accessMethod != NULL)
+		accessMethodId = get_table_am_oid(accessMethod, false);
+
+	/*
+	 * Create the relation.  Inherited defaults and constraints are passed in
+	 * for immediate handling --- since they don't need parsing, they can be
+	 * stored immediately.
+	 */
+	relationId = heap_create_with_catalog(relname,
+										  namespaceId,
+										  tablespaceId,
+										  InvalidOid,
+										  InvalidOid,
+										  ofTypeId,
+										  ownerId,
+										  accessMethodId,
+										  descriptor,
+										  list_concat(cookedDefaults,
+													  old_constraints),
+										  relkind,
+										  stmt->relation->relpersistence,
+										  false,
+										  false,
+										  stmt->oncommit,
+										  reloptions,
+										  true,
+										  allowSystemTableMods,
+										  false,
+										  InvalidOid,
+										  typaddress);
+
+	/*
+	 * We must bump the command counter to make the newly-created relation
+	 * tuple visible for opening.
+	 */
+	CommandCounterIncrement();
+
+	/*
+	 * Open the new relation and acquire exclusive lock on it.  This isn't
+	 * really necessary for locking out other backends (since they can't see
+	 * the new rel anyway until we commit), but it keeps the lock manager from
+	 * complaining about deadlock risks.
+	 */
+	rel = relation_open(relationId, AccessExclusiveLock);
+
+	/*
+	 * Now add any newly specified column default and generation expressions
+	 * to the new relation.  These are passed to us in the form of raw
+	 * parsetrees; we need to transform them to executable expression trees
+	 * before they can be added. The most convenient way to do that is to
+	 * apply the parser's transformExpr routine, but transformExpr doesn't
+	 * work unless we have a pre-existing relation. So, the transformation has
+	 * to be postponed to this final step of CREATE TABLE.
+	 *
+	 * This needs to be before processing the partitioning clauses because
+	 * those could refer to generated columns.
+	 */
+	if (rawDefaults)
+		AddRelationNewConstraints(rel, rawDefaults, NIL,
+								  true, true, false, queryString);
+
+	/*
+	 * Make column generation expressions visible for use by partitioning.
+	 */
+	CommandCounterIncrement();
+
+	/* Process and store partition bound, if any. */
+	if (stmt->partbound)
+	{
+		PartitionBoundSpec *bound;
+		ParseState *pstate;
+		Oid			parentId = linitial_oid(inheritOids),
+					defaultPartOid;
+		Relation	parent,
+					defaultRel = NULL;
+		ParseNamespaceItem *nsitem;
+
+		/* Already have strong enough lock on the parent */
+		parent = table_open(parentId, NoLock);
+
+		/*
+		 * We are going to try to validate the partition bound specification
+		 * against the partition key of parentRel, so it better have one.
+		 */
+		if (parent->rd_rel->relkind != RELKIND_PARTITIONED_TABLE)
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
+					 errmsg("\"%s\" is not partitioned",
+							RelationGetRelationName(parent))));
+
+		/*
+		 * The partition constraint of the default partition depends on the
+		 * partition bounds of every other partition. It is possible that
+		 * another backend might be about to execute a query on the default
+		 * partition table, and that the query relies on previously cached
+		 * default partition constraints. We must therefore take a table lock
+		 * strong enough to prevent all queries on the default partition from
+		 * proceeding until we commit and send out a shared-cache-inval notice
+		 * that will make them update their index lists.
+		 *
+		 * Order of locking: The relation being added won't be visible to
+		 * other backends until it is committed, hence here in
+		 * DefineRelation() the order of locking the default partition and the
+		 * relation being added does not matter. But at all other places we
+		 * need to lock the default relation before we lock the relation being
+		 * added or removed i.e. we should take the lock in same order at all
+		 * the places such that lock parent, lock default partition and then
+		 * lock the partition so as to avoid a deadlock.
+		 */
+		defaultPartOid =
+			get_default_oid_from_partdesc(RelationGetPartitionDesc(parent,
+																   true));
+		if (OidIsValid(defaultPartOid))
+			defaultRel = table_open(defaultPartOid, AccessExclusiveLock);
+
+		/* Transform the bound values */
+		pstate = make_parsestate(NULL);
+		pstate->p_sourcetext = queryString;
+
+		/*
+		 * Add an nsitem containing this relation, so that transformExpr
+		 * called on partition bound expressions is able to report errors
+		 * using a proper context.
+		 */
+		nsitem = addRangeTableEntryForRelation(pstate, rel, AccessShareLock,
+											   NULL, false, false);
+		addNSItemToQuery(pstate, nsitem, false, true, true);
+
+		bound = transformPartitionBound(pstate, parent, stmt->partbound);
+
+		/*
+		 * Check first that the new partition's bound is valid and does not
+		 * overlap with any of existing partitions of the parent.
+		 */
+		check_new_partition_bound(relname, parent, bound, pstate);
+
+		/*
+		 * If the default partition exists, its partition constraints will
+		 * change after the addition of this new partition such that it won't
+		 * allow any row that qualifies for this new partition. So, check that
+		 * the existing data in the default partition satisfies the constraint
+		 * as it will exist after adding this partition.
+		 */
+		if (OidIsValid(defaultPartOid))
+		{
+			check_default_partition_contents(parent, defaultRel, bound);
+			/* Keep the lock until commit. */
+			table_close(defaultRel, NoLock);
+		}
+
+		/* Update the pg_class entry. */
+		StorePartitionBound(rel, parent, bound);
+
+		table_close(parent, NoLock);
+	}
+
+	/* Store inheritance information for new rel. */
+	StoreCatalogInheritance(relationId, inheritOids, stmt->partbound != NULL);
+
+	/*
+	 * Process the partitioning specification (if any) and store the partition
+	 * key information into the catalog.
+	 */
+	if (partitioned)
+	{
+		ParseState *pstate;
+		char		strategy;
+		int			partnatts;
+		AttrNumber	partattrs[PARTITION_MAX_KEYS];
+		Oid			partopclass[PARTITION_MAX_KEYS];
+		Oid			partcollation[PARTITION_MAX_KEYS];
+		List	   *partexprs = NIL;
+
+		pstate = make_parsestate(NULL);
+		pstate->p_sourcetext = queryString;
+
+		partnatts = list_length(stmt->partspec->partParams);
+
+		/* Protect fixed-size arrays here and in executor */
+		if (partnatts > PARTITION_MAX_KEYS)
+			ereport(ERROR,
+					(errcode(ERRCODE_TOO_MANY_COLUMNS),
+					 errmsg("cannot partition using more than %d columns",
+							PARTITION_MAX_KEYS)));
+
+		/*
+		 * We need to transform the raw parsetrees corresponding to partition
+		 * expressions into executable expression trees.  Like column defaults
+		 * and CHECK constraints, we could not have done the transformation
+		 * earlier.
+		 */
+		stmt->partspec = transformPartitionSpec(rel, stmt->partspec,
+												&strategy);
+
+		ComputePartitionAttrs(pstate, rel, stmt->partspec->partParams,
+							  partattrs, &partexprs, partopclass,
+							  partcollation, strategy);
+
+		StorePartitionKey(rel, strategy, partnatts, partattrs, partexprs,
+						  partopclass, partcollation);
+
+		/* make it all visible */
+		CommandCounterIncrement();
+	}
+
+	/*
+	 * If we're creating a partition, create now all the indexes, triggers,
+	 * FKs defined in the parent.
+	 *
+	 * We can't do it earlier, because DefineIndex wants to know the partition
+	 * key which we just stored.
+	 */
+	if (stmt->partbound)
+	{
+		Oid			parentId = linitial_oid(inheritOids);
+		Relation	parent;
+		List	   *idxlist;
+		ListCell   *cell;
+
+		/* Already have strong enough lock on the parent */
+		parent = table_open(parentId, NoLock);
+		idxlist = RelationGetIndexList(parent);
+
+		/*
+		 * For each index in the parent table, create one in the partition
+		 */
+		foreach(cell, idxlist)
+		{
+			Relation	idxRel = index_open(lfirst_oid(cell), AccessShareLock);
+			AttrMap    *attmap;
+			IndexStmt  *idxstmt;
+			Oid			constraintOid;
+
+			if (rel->rd_rel->relkind == RELKIND_FOREIGN_TABLE)
+			{
+				if (idxRel->rd_index->indisunique)
+					ereport(ERROR,
+							(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+							 errmsg("cannot create foreign partition of partitioned table \"%s\"",
+									RelationGetRelationName(parent)),
+							 errdetail("Table \"%s\" contains indexes that are unique.",
+									   RelationGetRelationName(parent))));
+				else
+				{
+					index_close(idxRel, AccessShareLock);
+					continue;
+				}
+			}
+
+			attmap = build_attrmap_by_name(RelationGetDescr(rel),
+										   RelationGetDescr(parent));
+			idxstmt =
+				generateClonedIndexStmt(NULL, idxRel,
+										attmap, &constraintOid);
+			DefineIndex(RelationGetRelid(rel),
+						idxstmt,
+						InvalidOid,
+						RelationGetRelid(idxRel),
+						constraintOid,
+						false, false, false, false, false);
+
+			index_close(idxRel, AccessShareLock);
+		}
+
+		list_free(idxlist);
+
+		/*
+		 * If there are any row-level triggers, clone them to the new
+		 * partition.
+		 */
+		if (parent->trigdesc != NULL)
+			CloneRowTriggersToPartition(parent, rel);
+
+		/*
+		 * And foreign keys too.  Note that because we're freshly creating the
+		 * table, there is no need to verify these new constraints.
+		 */
+		CloneForeignKeyConstraints(NULL, parent, rel);
+
+		table_close(parent, NoLock);
+	}
+
+	/*
+	 * Now add any newly specified CHECK constraints to the new relation. Same
+	 * as for defaults above, but these need to come after partitioning is set
+	 * up.
+	 */
+	if (stmt->constraints)
+		AddRelationNewConstraints(rel, NIL, stmt->constraints,
+								  true, true, false, queryString);
+
+	ObjectAddressSet(address, RelationRelationId, relationId);
+
+	/*
+	 * Clean up.  We keep lock on new relation (although it shouldn't be
+	 * visible to anyone else anyway, until commit).
+	 */
+	relation_close(rel, NoLock);
+
+	return address;
+}
+
+/*
+ * Emit the right error or warning message for a "DROP" command issued on a
+ * non-existent relation
+ */
+static void
+DropErrorMsgNonExistent(RangeVar *rel, char rightkind, bool missing_ok)
+{
+	const struct dropmsgstrings *rentry;
+
+	if (rel->schemaname != NULL &&
+		!OidIsValid(LookupNamespaceNoError(rel->schemaname)))
+	{
+		if (!missing_ok)
+		{
+			ereport(ERROR,
+					(errcode(ERRCODE_UNDEFINED_SCHEMA),
+					 errmsg("schema \"%s\" does not exist", rel->schemaname)));
+		}
+		else
+		{
+			ereport(NOTICE,
+					(errmsg("schema \"%s\" does not exist, skipping",
+							rel->schemaname)));
+		}
+		return;
+	}
+
+	for (rentry = dropmsgstringarray; rentry->kind != '\0'; rentry++)
+	{
+		if (rentry->kind == rightkind)
+		{
+			if (!missing_ok)
+			{
+				ereport(ERROR,
+						(errcode(rentry->nonexistent_code),
+						 errmsg(rentry->nonexistent_msg, rel->relname)));
+			}
+			else
+			{
+				ereport(NOTICE, (errmsg(rentry->skipping_msg, rel->relname)));
+				break;
+			}
+		}
+	}
+
+	Assert(rentry->kind != '\0');	/* Should be impossible */
+}
+
+/*
+ * Emit the right error message for a "DROP" command issued on a
+ * relation of the wrong type
+ */
+static void
+DropErrorMsgWrongType(const char *relname, char wrongkind, char rightkind)
+{
+	const struct dropmsgstrings *rentry;
+	const struct dropmsgstrings *wentry;
+
+	for (rentry = dropmsgstringarray; rentry->kind != '\0'; rentry++)
+		if (rentry->kind == rightkind)
+			break;
+	Assert(rentry->kind != '\0');
+
+	for (wentry = dropmsgstringarray; wentry->kind != '\0'; wentry++)
+		if (wentry->kind == wrongkind)
+			break;
+	/* wrongkind could be something we don't have in our table... */
+
+	ereport(ERROR,
+			(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+			 errmsg(rentry->nota_msg, relname),
+			 (wentry->kind != '\0') ? errhint("%s", _(wentry->drophint_msg)) : 0));
+}
+
+/*
+ * RemoveRelations
+ *		Implements DROP TABLE, DROP INDEX, DROP SEQUENCE, DROP VIEW,
+ *		DROP MATERIALIZED VIEW, DROP FOREIGN TABLE
+ */
+void
+RemoveRelations(DropStmt *drop)
+{
+	ObjectAddresses *objects;
+	char		relkind;
+	ListCell   *cell;
+	int			flags = 0;
+	LOCKMODE	lockmode = AccessExclusiveLock;
+
+	/* DROP CONCURRENTLY uses a weaker lock, and has some restrictions */
+	if (drop->concurrent)
+	{
+		/*
+		 * Note that for temporary relations this lock may get upgraded later
+		 * on, but as no other session can access a temporary relation, this
+		 * is actually fine.
+		 */
+		lockmode = ShareUpdateExclusiveLock;
+		Assert(drop->removeType == OBJECT_INDEX);
+		if (list_length(drop->objects) != 1)
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("DROP INDEX CONCURRENTLY does not support dropping multiple objects")));
+		if (drop->behavior == DROP_CASCADE)
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("DROP INDEX CONCURRENTLY does not support CASCADE")));
+	}
+
+	/*
+	 * First we identify all the relations, then we delete them in a single
+	 * performMultipleDeletions() call.  This is to avoid unwanted DROP
+	 * RESTRICT errors if one of the relations depends on another.
+	 */
+
+	/* Determine required relkind */
+	switch (drop->removeType)
+	{
+		case OBJECT_TABLE:
+			relkind = RELKIND_RELATION;
+			break;
+
+		case OBJECT_INDEX:
+			relkind = RELKIND_INDEX;
+			break;
+
+		case OBJECT_SEQUENCE:
+			relkind = RELKIND_SEQUENCE;
+			break;
+
+		case OBJECT_VIEW:
+			relkind = RELKIND_VIEW;
+			break;
+
+		case OBJECT_MATVIEW:
+			relkind = RELKIND_MATVIEW;
+			break;
+
+		case OBJECT_FOREIGN_TABLE:
+			relkind = RELKIND_FOREIGN_TABLE;
+			break;
+
+		default:
+			elog(ERROR, "unrecognized drop object type: %d",
+				 (int) drop->removeType);
+			relkind = 0;		/* keep compiler quiet */
+			break;
+	}
+
+	/* Lock and validate each relation; build a list of object addresses */
+	objects = new_object_addresses();
+
+	foreach(cell, drop->objects)
+	{
+		RangeVar   *rel = makeRangeVarFromNameList((List *) lfirst(cell));
+		Oid			relOid;
+		ObjectAddress obj;
+		struct DropRelationCallbackState state;
+
+		/*
+		 * These next few steps are a great deal like relation_openrv, but we
+		 * don't bother building a relcache entry since we don't need it.
+		 *
+		 * Check for shared-cache-inval messages before trying to access the
+		 * relation.  This is needed to cover the case where the name
+		 * identifies a rel that has been dropped and recreated since the
+		 * start of our transaction: if we don't flush the old syscache entry,
+		 * then we'll latch onto that entry and suffer an error later.
+		 */
+		AcceptInvalidationMessages();
+
+		/* Look up the appropriate relation using namespace search. */
+		state.expected_relkind = relkind;
+		state.heap_lockmode = drop->concurrent ?
+			ShareUpdateExclusiveLock : AccessExclusiveLock;
+		/* We must initialize these fields to show that no locks are held: */
+		state.heapOid = InvalidOid;
+		state.partParentOid = InvalidOid;
+
+		relOid = RangeVarGetRelidExtended(rel, lockmode, RVR_MISSING_OK,
+										  RangeVarCallbackForDropRelation,
+										  (void *) &state);
+
+		/* Not there? */
+		if (!OidIsValid(relOid))
+		{
+			DropErrorMsgNonExistent(rel, relkind, drop->missing_ok);
+			continue;
+		}
+
+		/*
+		 * Decide if concurrent mode needs to be used here or not.  The
+		 * callback retrieved the rel's persistence for us.
+		 */
+		if (drop->concurrent &&
+			state.actual_relpersistence != RELPERSISTENCE_TEMP)
+		{
+			Assert(list_length(drop->objects) == 1 &&
+				   drop->removeType == OBJECT_INDEX);
+			flags |= PERFORM_DELETION_CONCURRENTLY;
+		}
+
+		/*
+		 * Concurrent index drop cannot be used with partitioned indexes,
+		 * either.
+		 */
+		if ((flags & PERFORM_DELETION_CONCURRENTLY) != 0 &&
+			state.actual_relkind == RELKIND_PARTITIONED_INDEX)
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("cannot drop partitioned index \"%s\" concurrently",
+							rel->relname)));
+
+		/*
+		 * If we're told to drop a partitioned index, we must acquire lock on
+		 * all the children of its parent partitioned table before proceeding.
+		 * Otherwise we'd try to lock the child index partitions before their
+		 * tables, leading to potential deadlock against other sessions that
+		 * will lock those objects in the other order.
+		 */
+		if (state.actual_relkind == RELKIND_PARTITIONED_INDEX)
+			(void) find_all_inheritors(state.heapOid,
+									   state.heap_lockmode,
+									   NULL);
+
+		/* OK, we're ready to delete this one */
+		obj.classId = RelationRelationId;
+		obj.objectId = relOid;
+		obj.objectSubId = 0;
+
+		add_exact_object_address(&obj, objects);
+	}
+
+	performMultipleDeletions(objects, drop->behavior, flags);
+
+	free_object_addresses(objects);
+}
+
+/*
+ * Before acquiring a table lock, check whether we have sufficient rights.
+ * In the case of DROP INDEX, also try to lock the table before the index.
+ * Also, if the table to be dropped is a partition, we try to lock the parent
+ * first.
+ */
+static void
+RangeVarCallbackForDropRelation(const RangeVar *rel, Oid relOid, Oid oldRelOid,
+								void *arg)
+{
+	HeapTuple	tuple;
+	struct DropRelationCallbackState *state;
+	char		expected_relkind;
+	bool		is_partition;
+	Form_pg_class classform;
+	LOCKMODE	heap_lockmode;
+	bool		invalid_system_index = false;
+
+	state = (struct DropRelationCallbackState *) arg;
+	heap_lockmode = state->heap_lockmode;
+
+	/*
+	 * If we previously locked some other index's heap, and the name we're
+	 * looking up no longer refers to that relation, release the now-useless
+	 * lock.
+	 */
+	if (relOid != oldRelOid && OidIsValid(state->heapOid))
+	{
+		UnlockRelationOid(state->heapOid, heap_lockmode);
+		state->heapOid = InvalidOid;
+	}
+
+	/*
+	 * Similarly, if we previously locked some other partition's heap, and the
+	 * name we're looking up no longer refers to that relation, release the
+	 * now-useless lock.
+	 */
+	if (relOid != oldRelOid && OidIsValid(state->partParentOid))
+	{
+		UnlockRelationOid(state->partParentOid, AccessExclusiveLock);
+		state->partParentOid = InvalidOid;
+	}
+
+	/* Didn't find a relation, so no need for locking or permission checks. */
+	if (!OidIsValid(relOid))
+		return;
+
+	tuple = SearchSysCache1(RELOID, ObjectIdGetDatum(relOid));
+	if (!HeapTupleIsValid(tuple))
+		return;					/* concurrently dropped, so nothing to do */
+	classform = (Form_pg_class) GETSTRUCT(tuple);
+	is_partition = classform->relispartition;
+
+	/* Pass back some data to save lookups in RemoveRelations */
+	state->actual_relkind = classform->relkind;
+	state->actual_relpersistence = classform->relpersistence;
+
+	/*
+	 * Both RELKIND_RELATION and RELKIND_PARTITIONED_TABLE are OBJECT_TABLE,
+	 * but RemoveRelations() can only pass one relkind for a given relation.
+	 * It chooses RELKIND_RELATION for both regular and partitioned tables.
+	 * That means we must be careful before giving the wrong type error when
+	 * the relation is RELKIND_PARTITIONED_TABLE.  An equivalent problem
+	 * exists with indexes.
+	 */
+	if (classform->relkind == RELKIND_PARTITIONED_TABLE)
+		expected_relkind = RELKIND_RELATION;
+	else if (classform->relkind == RELKIND_PARTITIONED_INDEX)
+		expected_relkind = RELKIND_INDEX;
+	else
+		expected_relkind = classform->relkind;
+
+	if (state->expected_relkind != expected_relkind)
+		DropErrorMsgWrongType(rel->relname, classform->relkind,
+							  state->expected_relkind);
+
+	/* Allow DROP to either table owner or schema owner */
+	if (!pg_class_ownercheck(relOid, GetUserId()) &&
+		!pg_namespace_ownercheck(classform->relnamespace, GetUserId()))
+		aclcheck_error(ACLCHECK_NOT_OWNER,
+					   get_relkind_objtype(classform->relkind),
+					   rel->relname);
+
+	/*
+	 * Check the case of a system index that might have been invalidated by a
+	 * failed concurrent process and allow its drop. For the time being, this
+	 * only concerns indexes of toast relations that became invalid during a
+	 * REINDEX CONCURRENTLY process.
+	 */
+	if (IsSystemClass(relOid, classform) && classform->relkind == RELKIND_INDEX)
+	{
+		HeapTuple	locTuple;
+		Form_pg_index indexform;
+		bool		indisvalid;
+
+		locTuple = SearchSysCache1(INDEXRELID, ObjectIdGetDatum(relOid));
+		if (!HeapTupleIsValid(locTuple))
+		{
+			ReleaseSysCache(tuple);
+			return;
+		}
+
+		indexform = (Form_pg_index) GETSTRUCT(locTuple);
+		indisvalid = indexform->indisvalid;
+		ReleaseSysCache(locTuple);
+
+		/* Mark object as being an invalid index of system catalogs */
+		if (!indisvalid)
+			invalid_system_index = true;
+	}
+
+	/* In the case of an invalid index, it is fine to bypass this check */
+	if (!invalid_system_index && !allowSystemTableMods && IsSystemClass(relOid, classform))
+		ereport(ERROR,
+				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
+				 errmsg("permission denied: \"%s\" is a system catalog",
+						rel->relname)));
+
+	ReleaseSysCache(tuple);
+
+	/*
+	 * In DROP INDEX, attempt to acquire lock on the parent table before
+	 * locking the index.  index_drop() will need this anyway, and since
+	 * regular queries lock tables before their indexes, we risk deadlock if
+	 * we do it the other way around.  No error if we don't find a pg_index
+	 * entry, though --- the relation may have been dropped.  Note that this
+	 * code will execute for either plain or partitioned indexes.
+	 */
+	if (expected_relkind == RELKIND_INDEX &&
+		relOid != oldRelOid)
+	{
+		state->heapOid = IndexGetRelation(relOid, true);
+		if (OidIsValid(state->heapOid))
+			LockRelationOid(state->heapOid, heap_lockmode);
+	}
+
+	/*
+	 * Similarly, if the relation is a partition, we must acquire lock on its
+	 * parent before locking the partition.  That's because queries lock the
+	 * parent before its partitions, so we risk deadlock if we do it the other
+	 * way around.
+	 */
+	if (is_partition && relOid != oldRelOid)
+	{
+		state->partParentOid = get_partition_parent(relOid, true);
+		if (OidIsValid(state->partParentOid))
+			LockRelationOid(state->partParentOid, AccessExclusiveLock);
+	}
+}
+
+/*
+ * ExecuteTruncate
+ *		Executes a TRUNCATE command.
+ *
+ * This is a multi-relation truncate.  We first open and grab exclusive
+ * lock on all relations involved, checking permissions and otherwise
+ * verifying that the relation is OK for truncation.  Note that if relations
+ * are foreign tables, at this stage, we have not yet checked that their
+ * foreign data in external data sources are OK for truncation.  These are
+ * checked when foreign data are actually truncated later.  In CASCADE mode,
+ * relations having FK references to the targeted relations are automatically
+ * added to the group; in RESTRICT mode, we check that all FK references are
+ * internal to the group that's being truncated.  Finally all the relations
+ * are truncated and reindexed.
+ */
+void
+ExecuteTruncate(TruncateStmt *stmt)
+{
+	List	   *rels = NIL;
+	List	   *relids = NIL;
+	List	   *relids_logged = NIL;
+	ListCell   *cell;
+
+	/*
+	 * Open, exclusive-lock, and check all the explicitly-specified relations
+	 */
+	foreach(cell, stmt->relations)
+	{
+		RangeVar   *rv = lfirst(cell);
+		Relation	rel;
+		bool		recurse = rv->inh;
+		Oid			myrelid;
+		LOCKMODE	lockmode = AccessExclusiveLock;
+
+		myrelid = RangeVarGetRelidExtended(rv, lockmode,
+										   0, RangeVarCallbackForTruncate,
+										   NULL);
+
+		/* don't throw error for "TRUNCATE foo, foo" */
+		if (list_member_oid(relids, myrelid))
+			continue;
+
+		/* open the relation, we already hold a lock on it */
+		rel = table_open(myrelid, NoLock);
+
+		/*
+		 * RangeVarGetRelidExtended() has done most checks with its callback,
+		 * but other checks with the now-opened Relation remain.
+		 */
+		truncate_check_activity(rel);
+
+		rels = lappend(rels, rel);
+		relids = lappend_oid(relids, myrelid);
+
+		/* Log this relation only if needed for logical decoding */
+		if (RelationIsLogicallyLogged(rel))
+			relids_logged = lappend_oid(relids_logged, myrelid);
+
+		if (recurse)
+		{
+			ListCell   *child;
+			List	   *children;
+
+			children = find_all_inheritors(myrelid, lockmode, NULL);
+
+			foreach(child, children)
+			{
+				Oid			childrelid = lfirst_oid(child);
+
+				if (list_member_oid(relids, childrelid))
+					continue;
+
+				/* find_all_inheritors already got lock */
+				rel = table_open(childrelid, NoLock);
+
+				/*
+				 * It is possible that the parent table has children that are
+				 * temp tables of other backends.  We cannot safely access
+				 * such tables (because of buffering issues), and the best
+				 * thing to do is to silently ignore them.  Note that this
+				 * check is the same as one of the checks done in
+				 * truncate_check_activity() called below, still it is kept
+				 * here for simplicity.
+				 */
+				if (RELATION_IS_OTHER_TEMP(rel))
+				{
+					table_close(rel, lockmode);
+					continue;
+				}
+
+				/*
+				 * Inherited TRUNCATE commands perform access permission
+				 * checks on the parent table only. So we skip checking the
+				 * children's permissions and don't call
+				 * truncate_check_perms() here.
+				 */
+				truncate_check_rel(RelationGetRelid(rel), rel->rd_rel);
+				truncate_check_activity(rel);
+
+				rels = lappend(rels, rel);
+				relids = lappend_oid(relids, childrelid);
+
+				/* Log this relation only if needed for logical decoding */
+				if (RelationIsLogicallyLogged(rel))
+					relids_logged = lappend_oid(relids_logged, childrelid);
+			}
+		}
+		else if (rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
+			ereport(ERROR,
+					(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+					 errmsg("cannot truncate only a partitioned table"),
+					 errhint("Do not specify the ONLY keyword, or use TRUNCATE ONLY on the partitions directly.")));
+	}
+
+	ExecuteTruncateGuts(rels, relids, relids_logged,
+						stmt->behavior, stmt->restart_seqs);
+
+	/* And close the rels */
+	foreach(cell, rels)
+	{
+		Relation	rel = (Relation) lfirst(cell);
+
+		table_close(rel, NoLock);
+	}
+}
+
+/*
+ * ExecuteTruncateGuts
+ *
+ * Internal implementation of TRUNCATE.  This is called by the actual TRUNCATE
+ * command (see above) as well as replication subscribers that execute a
+ * replicated TRUNCATE action.
+ *
+ * explicit_rels is the list of Relations to truncate that the command
+ * specified.  relids is the list of Oids corresponding to explicit_rels.
+ * relids_logged is the list of Oids (a subset of relids) that require
+ * WAL-logging.  This is all a bit redundant, but the existing callers have
+ * this information handy in this form.
+ */
+void
+ExecuteTruncateGuts(List *explicit_rels,
+					List *relids,
+					List *relids_logged,
+					DropBehavior behavior, bool restart_seqs)
+{
+	List	   *rels;
+	List	   *seq_relids = NIL;
+	HTAB	   *ft_htab = NULL;
+	EState	   *estate;
+	ResultRelInfo *resultRelInfos;
+	ResultRelInfo *resultRelInfo;
+	SubTransactionId mySubid;
+	ListCell   *cell;
+	Oid		   *logrelids;
+
+	/*
+	 * Check the explicitly-specified relations.
+	 *
+	 * In CASCADE mode, suck in all referencing relations as well.  This
+	 * requires multiple iterations to find indirectly-dependent relations. At
+	 * each phase, we need to exclusive-lock new rels before looking for their
+	 * dependencies, else we might miss something.  Also, we check each rel as
+	 * soon as we open it, to avoid a faux pas such as holding lock for a long
+	 * time on a rel we have no permissions for.
+	 */
+	rels = list_copy(explicit_rels);
+	if (behavior == DROP_CASCADE)
+	{
+		for (;;)
+		{
+			List	   *newrelids;
+
+			newrelids = heap_truncate_find_FKs(relids);
+			if (newrelids == NIL)
+				break;			/* nothing else to add */
+
+			foreach(cell, newrelids)
+			{
+				Oid			relid = lfirst_oid(cell);
+				Relation	rel;
+
+				rel = table_open(relid, AccessExclusiveLock);
+				ereport(NOTICE,
+						(errmsg("truncate cascades to table \"%s\"",
+								RelationGetRelationName(rel))));
+				truncate_check_rel(relid, rel->rd_rel);
+				truncate_check_perms(relid, rel->rd_rel);
+				truncate_check_activity(rel);
+				rels = lappend(rels, rel);
+				relids = lappend_oid(relids, relid);
+
+				/* Log this relation only if needed for logical decoding */
+				if (RelationIsLogicallyLogged(rel))
+					relids_logged = lappend_oid(relids_logged, relid);
+			}
+		}
+	}
+
+	/*
+	 * Check foreign key references.  In CASCADE mode, this should be
+	 * unnecessary since we just pulled in all the references; but as a
+	 * cross-check, do it anyway if in an Assert-enabled build.
+	 */
+#ifdef USE_ASSERT_CHECKING
+	heap_truncate_check_FKs(rels, false);
+#else
+	if (behavior == DROP_RESTRICT)
+		heap_truncate_check_FKs(rels, false);
+#endif
+
+	/*
+	 * If we are asked to restart sequences, find all the sequences, lock them
+	 * (we need AccessExclusiveLock for ResetSequence), and check permissions.
+	 * We want to do this early since it's pointless to do all the truncation
+	 * work only to fail on sequence permissions.
+	 */
+	if (restart_seqs)
+	{
+		foreach(cell, rels)
+		{
+			Relation	rel = (Relation) lfirst(cell);
+			List	   *seqlist = getOwnedSequences(RelationGetRelid(rel));
+			ListCell   *seqcell;
+
+			foreach(seqcell, seqlist)
+			{
+				Oid			seq_relid = lfirst_oid(seqcell);
+				Relation	seq_rel;
+
+				seq_rel = relation_open(seq_relid, AccessExclusiveLock);
+
+				/* This check must match AlterSequence! */
+				if (!pg_class_ownercheck(seq_relid, GetUserId()))
+					aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SEQUENCE,
+								   RelationGetRelationName(seq_rel));
+
+				seq_relids = lappend_oid(seq_relids, seq_relid);
+
+				relation_close(seq_rel, NoLock);
+			}
+		}
+	}
+
+	/* Prepare to catch AFTER triggers. */
+	AfterTriggerBeginQuery();
+
+	/*
+	 * To fire triggers, we'll need an EState as well as a ResultRelInfo for
+	 * each relation.  We don't need to call ExecOpenIndices, though.
+	 *
+	 * We put the ResultRelInfos in the es_opened_result_relations list, even
+	 * though we don't have a range table and don't populate the
+	 * es_result_relations array.  That's a bit bogus, but it's enough to make
+	 * ExecGetTriggerResultRel() find them.
+	 */
+	estate = CreateExecutorState();
+	resultRelInfos = (ResultRelInfo *)
+		palloc(list_length(rels) * sizeof(ResultRelInfo));
+	resultRelInfo = resultRelInfos;
+	foreach(cell, rels)
+	{
+		Relation	rel = (Relation) lfirst(cell);
+
+		InitResultRelInfo(resultRelInfo,
+						  rel,
+						  0,	/* dummy rangetable index */
+						  NULL,
+						  0);
+		estate->es_opened_result_relations =
+			lappend(estate->es_opened_result_relations, resultRelInfo);
+		resultRelInfo++;
+	}
+
+	/*
+	 * Process all BEFORE STATEMENT TRUNCATE triggers before we begin
+	 * truncating (this is because one of them might throw an error). Also, if
+	 * we were to allow them to prevent statement execution, that would need
+	 * to be handled here.
+	 */
+	resultRelInfo = resultRelInfos;
+	foreach(cell, rels)
+	{
+		ExecBSTruncateTriggers(estate, resultRelInfo);
+		resultRelInfo++;
+	}
+
+	/*
+	 * OK, truncate each table.
+	 */
+	mySubid = GetCurrentSubTransactionId();
+
+	foreach(cell, rels)
+	{
+		Relation	rel = (Relation) lfirst(cell);
+
+		/* Skip partitioned tables as there is nothing to do */
+		if (rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
+			continue;
+
+		/*
+		 * Build the lists of foreign tables belonging to each foreign server
+		 * and pass each list to the foreign data wrapper's callback function,
+		 * so that each server can truncate its all foreign tables in bulk.
+		 * Each list is saved as a single entry in a hash table that uses the
+		 * server OID as lookup key.
+		 */
+		if (rel->rd_rel->relkind == RELKIND_FOREIGN_TABLE)
+		{
+			Oid			serverid = GetForeignServerIdByRelId(RelationGetRelid(rel));
+			bool		found;
+			ForeignTruncateInfo *ft_info;
+
+			/* First time through, initialize hashtable for foreign tables */
+			if (!ft_htab)
+			{
+				HASHCTL		hctl;
+
+				memset(&hctl, 0, sizeof(HASHCTL));
+				hctl.keysize = sizeof(Oid);
+				hctl.entrysize = sizeof(ForeignTruncateInfo);
+				hctl.hcxt = CurrentMemoryContext;
+
+				ft_htab = hash_create("TRUNCATE for Foreign Tables",
+									  32,	/* start small and extend */
+									  &hctl,
+									  HASH_ELEM | HASH_BLOBS | HASH_CONTEXT);
+			}
+
+			/* Find or create cached entry for the foreign table */
+			ft_info = hash_search(ft_htab, &serverid, HASH_ENTER, &found);
+			if (!found)
+			{
+				ft_info->serverid = serverid;
+				ft_info->rels = NIL;
+			}
+
+			/*
+			 * Save the foreign table in the entry of the server that the
+			 * foreign table belongs to.
+			 */
+			ft_info->rels = lappend(ft_info->rels, rel);
+			continue;
+		}
+
+		/*
+		 * Normally, we need a transaction-safe truncation here.  However, if
+		 * the table was either created in the current (sub)transaction or has
+		 * a new relfilenode in the current (sub)transaction, then we can just
+		 * truncate it in-place, because a rollback would cause the whole
+		 * table or the current physical file to be thrown away anyway.
+		 */
+		if (rel->rd_createSubid == mySubid ||
+			rel->rd_newRelfilenodeSubid == mySubid)
+		{
+			/* Immediate, non-rollbackable truncation is OK */
+			heap_truncate_one_rel(rel);
+		}
+		else
+		{
+			Oid			heap_relid;
+			Oid			toast_relid;
+			ReindexParams reindex_params = {0};
+
+			/*
+			 * This effectively deletes all rows in the table, and may be done
+			 * in a serializable transaction.  In that case we must record a
+			 * rw-conflict in to this transaction from each transaction
+			 * holding a predicate lock on the table.
+			 */
+			CheckTableForSerializableConflictIn(rel);
+
+			/*
+			 * Need the full transaction-safe pushups.
+			 *
+			 * Create a new empty storage file for the relation, and assign it
+			 * as the relfilenode value. The old storage file is scheduled for
+			 * deletion at commit.
+			 */
+			RelationSetNewRelfilenode(rel, rel->rd_rel->relpersistence);
+
+			heap_relid = RelationGetRelid(rel);
+
+			/*
+			 * The same for the toast table, if any.
+			 */
+			toast_relid = rel->rd_rel->reltoastrelid;
+			if (OidIsValid(toast_relid))
+			{
+				Relation	toastrel = relation_open(toast_relid,
+													 AccessExclusiveLock);
+
+				RelationSetNewRelfilenode(toastrel,
+										  toastrel->rd_rel->relpersistence);
+				table_close(toastrel, NoLock);
+			}
+
+			/*
+			 * Reconstruct the indexes to match, and we're done.
+			 */
+			reindex_relation(heap_relid, REINDEX_REL_PROCESS_TOAST,
+							 &reindex_params);
+		}
+
+		pgstat_count_truncate(rel);
+	}
+
+	/* Now go through the hash table, and truncate foreign tables */
+	if (ft_htab)
+	{
+		ForeignTruncateInfo *ft_info;
+		HASH_SEQ_STATUS seq;
+
+		hash_seq_init(&seq, ft_htab);
+
+		PG_TRY();
+		{
+			while ((ft_info = hash_seq_search(&seq)) != NULL)
+			{
+				FdwRoutine *routine = GetFdwRoutineByServerId(ft_info->serverid);
+
+				/* truncate_check_rel() has checked that already */
+				Assert(routine->ExecForeignTruncate != NULL);
+
+				routine->ExecForeignTruncate(ft_info->rels,
+											 behavior,
+											 restart_seqs);
+			}
+		}
+		PG_FINALLY();
+		{
+			hash_destroy(ft_htab);
+		}
+		PG_END_TRY();
+	}
+
+	/*
+	 * Restart owned sequences if we were asked to.
+	 */
+	foreach(cell, seq_relids)
+	{
+		Oid			seq_relid = lfirst_oid(cell);
+
+		ResetSequence(seq_relid);
+	}
+
+	/*
+	 * Write a WAL record to allow this set of actions to be logically
+	 * decoded.
+	 *
+	 * Assemble an array of relids so we can write a single WAL record for the
+	 * whole action.
+	 */
+	if (list_length(relids_logged) > 0)
+	{
+		xl_heap_truncate xlrec;
+		int			i = 0;
+
+		/* should only get here if wal_level >= logical */
+		Assert(XLogLogicalInfoActive());
+
+		logrelids = palloc(list_length(relids_logged) * sizeof(Oid));
+		foreach(cell, relids_logged)
+			logrelids[i++] = lfirst_oid(cell);
+
+		xlrec.dbId = MyDatabaseId;
+		xlrec.nrelids = list_length(relids_logged);
+		xlrec.flags = 0;
+		if (behavior == DROP_CASCADE)
+			xlrec.flags |= XLH_TRUNCATE_CASCADE;
+		if (restart_seqs)
+			xlrec.flags |= XLH_TRUNCATE_RESTART_SEQS;
+
+		XLogBeginInsert();
+		XLogRegisterData((char *) &xlrec, SizeOfHeapTruncate);
+		XLogRegisterData((char *) logrelids, list_length(relids_logged) * sizeof(Oid));
+
+		XLogSetRecordFlags(XLOG_INCLUDE_ORIGIN);
+
+		(void) XLogInsert(RM_HEAP_ID, XLOG_HEAP_TRUNCATE);
+	}
+
+	/*
+	 * Process all AFTER STATEMENT TRUNCATE triggers.
+	 */
+	resultRelInfo = resultRelInfos;
+	foreach(cell, rels)
+	{
+		ExecASTruncateTriggers(estate, resultRelInfo);
+		resultRelInfo++;
+	}
+
+	/* Handle queued AFTER triggers */
+	AfterTriggerEndQuery(estate);
+
+	/* We can clean up the EState now */
+	FreeExecutorState(estate);
+
+	/*
+	 * Close any rels opened by CASCADE (can't do this while EState still
+	 * holds refs)
+	 */
+	rels = list_difference_ptr(rels, explicit_rels);
+	foreach(cell, rels)
+	{
+		Relation	rel = (Relation) lfirst(cell);
+
+		table_close(rel, NoLock);
+	}
+}
+
+/*
+ * Check that a given relation is safe to truncate.  Subroutine for
+ * ExecuteTruncate() and RangeVarCallbackForTruncate().
+ */
+static void
+truncate_check_rel(Oid relid, Form_pg_class reltuple)
+{
+	char	   *relname = NameStr(reltuple->relname);
+
+	/*
+	 * Only allow truncate on regular tables, foreign tables using foreign
+	 * data wrappers supporting TRUNCATE and partitioned tables (although, the
+	 * latter are only being included here for the following checks; no
+	 * physical truncation will occur in their case.).
+	 */
+	if (reltuple->relkind == RELKIND_FOREIGN_TABLE)
+	{
+		Oid			serverid = GetForeignServerIdByRelId(relid);
+		FdwRoutine *fdwroutine = GetFdwRoutineByServerId(serverid);
+
+		if (!fdwroutine->ExecForeignTruncate)
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("cannot truncate foreign table \"%s\"",
+							relname)));
+	}
+	else if (reltuple->relkind != RELKIND_RELATION &&
+			 reltuple->relkind != RELKIND_PARTITIONED_TABLE)
+		ereport(ERROR,
+				(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+				 errmsg("\"%s\" is not a table", relname)));
+
+	/*
+	 * Most system catalogs can't be truncated at all, or at least not unless
+	 * allow_system_table_mods=on. As an exception, however, we allow
+	 * pg_largeobject to be truncated as part of pg_upgrade, because we need
+	 * to change its relfilenode to match the old cluster, and allowing a
+	 * TRUNCATE command to be executed is the easiest way of doing that.
+	 */
+	if (!allowSystemTableMods && IsSystemClass(relid, reltuple)
+		&& (!IsBinaryUpgrade || relid != LargeObjectRelationId))
+		ereport(ERROR,
+				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
+				 errmsg("permission denied: \"%s\" is a system catalog",
+						relname)));
+
+	InvokeObjectTruncateHook(relid);
+}
+
+/*
+ * Check that current user has the permission to truncate given relation.
+ */
+static void
+truncate_check_perms(Oid relid, Form_pg_class reltuple)
+{
+	char	   *relname = NameStr(reltuple->relname);
+	AclResult	aclresult;
+
+	/* Permissions checks */
+	aclresult = pg_class_aclcheck(relid, GetUserId(), ACL_TRUNCATE);
+	if (aclresult != ACLCHECK_OK)
+		aclcheck_error(aclresult, get_relkind_objtype(reltuple->relkind),
+					   relname);
+}
+
+/*
+ * Set of extra sanity checks to check if a given relation is safe to
+ * truncate.  This is split with truncate_check_rel() as
+ * RangeVarCallbackForTruncate() cannot open a Relation yet.
+ */
+static void
+truncate_check_activity(Relation rel)
+{
+	/*
+	 * Don't allow truncate on temp tables of other backends ... their local
+	 * buffer manager is not going to cope.
+	 */
+	if (RELATION_IS_OTHER_TEMP(rel))
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("cannot truncate temporary tables of other sessions")));
+
+	/*
+	 * Also check for active uses of the relation in the current transaction,
+	 * including open scans and pending AFTER trigger events.
+	 */
+	CheckTableNotInUse(rel, "TRUNCATE");
+}
+
+/*
+ * storage_name
+ *	  returns the name corresponding to a typstorage/attstorage enum value
+ */
+static const char *
+storage_name(char c)
+{
+	switch (c)
+	{
+		case TYPSTORAGE_PLAIN:
+			return "PLAIN";
+		case TYPSTORAGE_EXTERNAL:
+			return "EXTERNAL";
+		case TYPSTORAGE_EXTENDED:
+			return "EXTENDED";
+		case TYPSTORAGE_MAIN:
+			return "MAIN";
+		default:
+			return "???";
+	}
+}
+
+/*----------
+ * MergeAttributes
+ *		Returns new schema given initial schema and superclasses.
+ *
+ * Input arguments:
+ * 'schema' is the column/attribute definition for the table. (It's a list
+ *		of ColumnDef's.) It is destructively changed.
+ * 'supers' is a list of OIDs of parent relations, already locked by caller.
+ * 'relpersistence' is the persistence type of the table.
+ * 'is_partition' tells if the table is a partition.
+ *
+ * Output arguments:
+ * 'supconstr' receives a list of constraints belonging to the parents,
+ *		updated as necessary to be valid for the child.
+ *
+ * Return value:
+ * Completed schema list.
+ *
+ * Notes:
+ *	  The order in which the attributes are inherited is very important.
+ *	  Intuitively, the inherited attributes should come first. If a table
+ *	  inherits from multiple parents, the order of those attributes are
+ *	  according to the order of the parents specified in CREATE TABLE.
+ *
+ *	  Here's an example:
+ *
+ *		create table person (name text, age int4, location point);
+ *		create table emp (salary int4, manager text) inherits(person);
+ *		create table student (gpa float8) inherits (person);
+ *		create table stud_emp (percent int4) inherits (emp, student);
+ *
+ *	  The order of the attributes of stud_emp is:
+ *
+ *							person {1:name, 2:age, 3:location}
+ *							/	 \
+ *			   {6:gpa}	student   emp {4:salary, 5:manager}
+ *							\	 /
+ *						   stud_emp {7:percent}
+ *
+ *	   If the same attribute name appears multiple times, then it appears
+ *	   in the result table in the proper location for its first appearance.
+ *
+ *	   Constraints (including NOT NULL constraints) for the child table
+ *	   are the union of all relevant constraints, from both the child schema
+ *	   and parent tables.
+ *
+ *	   The default value for a child column is defined as:
+ *		(1) If the child schema specifies a default, that value is used.
+ *		(2) If neither the child nor any parent specifies a default, then
+ *			the column will not have a default.
+ *		(3) If conflicting defaults are inherited from different parents
+ *			(and not overridden by the child), an error is raised.
+ *		(4) Otherwise the inherited default is used.
+ *		Rule (3) is new in Postgres 7.1; in earlier releases you got a
+ *		rather arbitrary choice of which parent default to use.
+ *----------
+ */
+static List *
+MergeAttributes(List *schema, List *supers, char relpersistence,
+				bool is_partition, List **supconstr)
+{
+	List	   *inhSchema = NIL;
+	List	   *constraints = NIL;
+	bool		have_bogus_defaults = false;
+	int			child_attno;
+	static Node bogus_marker = {0}; /* marks conflicting defaults */
+	List	   *saved_schema = NIL;
+	ListCell   *entry;
+
+	/*
+	 * Check for and reject tables with too many columns. We perform this
+	 * check relatively early for two reasons: (a) we don't run the risk of
+	 * overflowing an AttrNumber in subsequent code (b) an O(n^2) algorithm is
+	 * okay if we're processing <= 1600 columns, but could take minutes to
+	 * execute if the user attempts to create a table with hundreds of
+	 * thousands of columns.
+	 *
+	 * Note that we also need to check that we do not exceed this figure after
+	 * including columns from inherited relations.
+	 */
+	if (list_length(schema) > MaxHeapAttributeNumber)
+		ereport(ERROR,
+				(errcode(ERRCODE_TOO_MANY_COLUMNS),
+				 errmsg("tables can have at most %d columns",
+						MaxHeapAttributeNumber)));
+
+	/*
+	 * Check for duplicate names in the explicit list of attributes.
+	 *
+	 * Although we might consider merging such entries in the same way that we
+	 * handle name conflicts for inherited attributes, it seems to make more
+	 * sense to assume such conflicts are errors.
+	 *
+	 * We don't use foreach() here because we have two nested loops over the
+	 * schema list, with possible element deletions in the inner one.  If we
+	 * used foreach_delete_current() it could only fix up the state of one of
+	 * the loops, so it seems cleaner to use looping over list indexes for
+	 * both loops.  Note that any deletion will happen beyond where the outer
+	 * loop is, so its index never needs adjustment.
+	 */
+	for (int coldefpos = 0; coldefpos < list_length(schema); coldefpos++)
+	{
+		ColumnDef  *coldef = list_nth_node(ColumnDef, schema, coldefpos);
+
+		if (!is_partition && coldef->typeName == NULL)
+		{
+			/*
+			 * Typed table column option that does not belong to a column from
+			 * the type.  This works because the columns from the type come
+			 * first in the list.  (We omit this check for partition column
+			 * lists; those are processed separately below.)
+			 */
+			ereport(ERROR,
+					(errcode(ERRCODE_UNDEFINED_COLUMN),
+					 errmsg("column \"%s\" does not exist",
+							coldef->colname)));
+		}
+
+		/* restpos scans all entries beyond coldef; incr is in loop body */
+		for (int restpos = coldefpos + 1; restpos < list_length(schema);)
+		{
+			ColumnDef  *restdef = list_nth_node(ColumnDef, schema, restpos);
+
+			if (strcmp(coldef->colname, restdef->colname) == 0)
+			{
+				if (coldef->is_from_type)
+				{
+					/*
+					 * merge the column options into the column from the type
+					 */
+					coldef->is_not_null = restdef->is_not_null;
+					coldef->raw_default = restdef->raw_default;
+					coldef->cooked_default = restdef->cooked_default;
+					coldef->constraints = restdef->constraints;
+					coldef->is_from_type = false;
+					schema = list_delete_nth_cell(schema, restpos);
+				}
+				else
+					ereport(ERROR,
+							(errcode(ERRCODE_DUPLICATE_COLUMN),
+							 errmsg("column \"%s\" specified more than once",
+									coldef->colname)));
+			}
+			else
+				restpos++;
+		}
+	}
+
+	/*
+	 * In case of a partition, there are no new column definitions, only dummy
+	 * ColumnDefs created for column constraints.  Set them aside for now and
+	 * process them at the end.
+	 */
+	if (is_partition)
+	{
+		saved_schema = schema;
+		schema = NIL;
+	}
+
+	/*
+	 * Scan the parents left-to-right, and merge their attributes to form a
+	 * list of inherited attributes (inhSchema).  Also check to see if we need
+	 * to inherit an OID column.
+	 */
+	child_attno = 0;
+	foreach(entry, supers)
+	{
+		Oid			parent = lfirst_oid(entry);
+		Relation	relation;
+		TupleDesc	tupleDesc;
+		TupleConstr *constr;
+		AttrMap    *newattmap;
+		List	   *inherited_defaults;
+		List	   *cols_with_defaults;
+		AttrNumber	parent_attno;
+		ListCell   *lc1;
+		ListCell   *lc2;
+
+		/* caller already got lock */
+		relation = table_open(parent, NoLock);
+
+		/*
+		 * Check for active uses of the parent partitioned table in the
+		 * current transaction, such as being used in some manner by an
+		 * enclosing command.
+		 */
+		if (is_partition)
+			CheckTableNotInUse(relation, "CREATE TABLE .. PARTITION OF");
+
+		/*
+		 * We do not allow partitioned tables and partitions to participate in
+		 * regular inheritance.
+		 */
+		if (relation->rd_rel->relkind == RELKIND_PARTITIONED_TABLE &&
+			!is_partition)
+			ereport(ERROR,
+					(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+					 errmsg("cannot inherit from partitioned table \"%s\"",
+							RelationGetRelationName(relation))));
+		if (relation->rd_rel->relispartition && !is_partition)
+			ereport(ERROR,
+					(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+					 errmsg("cannot inherit from partition \"%s\"",
+							RelationGetRelationName(relation))));
+
+		if (relation->rd_rel->relkind != RELKIND_RELATION &&
+			relation->rd_rel->relkind != RELKIND_FOREIGN_TABLE &&
+			relation->rd_rel->relkind != RELKIND_PARTITIONED_TABLE)
+			ereport(ERROR,
+					(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+					 errmsg("inherited relation \"%s\" is not a table or foreign table",
+							RelationGetRelationName(relation))));
+
+		/*
+		 * If the parent is permanent, so must be all of its partitions.  Note
+		 * that inheritance allows that case.
+		 */
+		if (is_partition &&
+			relation->rd_rel->relpersistence != RELPERSISTENCE_TEMP &&
+			relpersistence == RELPERSISTENCE_TEMP)
+			ereport(ERROR,
+					(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+					 errmsg("cannot create a temporary relation as partition of permanent relation \"%s\"",
+							RelationGetRelationName(relation))));
+
+		/* Permanent rels cannot inherit from temporary ones */
+		if (relpersistence != RELPERSISTENCE_TEMP &&
+			relation->rd_rel->relpersistence == RELPERSISTENCE_TEMP)
+			ereport(ERROR,
+					(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+					 errmsg(!is_partition
+							? "cannot inherit from temporary relation \"%s\""
+							: "cannot create a permanent relation as partition of temporary relation \"%s\"",
+							RelationGetRelationName(relation))));
+
+		/* If existing rel is temp, it must belong to this session */
+		if (relation->rd_rel->relpersistence == RELPERSISTENCE_TEMP &&
+			!relation->rd_islocaltemp)
+			ereport(ERROR,
+					(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+					 errmsg(!is_partition
+							? "cannot inherit from temporary relation of another session"
+							: "cannot create as partition of temporary relation of another session")));
+
+		/*
+		 * We should have an UNDER permission flag for this, but for now,
+		 * demand that creator of a child table own the parent.
+		 */
+		if (!pg_class_ownercheck(RelationGetRelid(relation), GetUserId()))
+			aclcheck_error(ACLCHECK_NOT_OWNER, get_relkind_objtype(relation->rd_rel->relkind),
+						   RelationGetRelationName(relation));
+
+		tupleDesc = RelationGetDescr(relation);
+		constr = tupleDesc->constr;
+
+		/*
+		 * newattmap->attnums[] will contain the child-table attribute numbers
+		 * for the attributes of this parent table.  (They are not the same
+		 * for parents after the first one, nor if we have dropped columns.)
+		 */
+		newattmap = make_attrmap(tupleDesc->natts);
+
+		/* We can't process inherited defaults until newattmap is complete. */
+		inherited_defaults = cols_with_defaults = NIL;
+
+		for (parent_attno = 1; parent_attno <= tupleDesc->natts;
+			 parent_attno++)
+		{
+			Form_pg_attribute attribute = TupleDescAttr(tupleDesc,
+														parent_attno - 1);
+			char	   *attributeName = NameStr(attribute->attname);
+			int			exist_attno;
+			ColumnDef  *def;
+
+			/*
+			 * Ignore dropped columns in the parent.
+			 */
+			if (attribute->attisdropped)
+				continue;		/* leave newattmap->attnums entry as zero */
+
+			/*
+			 * Does it conflict with some previously inherited column?
+			 */
+			exist_attno = findAttrByName(attributeName, inhSchema);
+			if (exist_attno > 0)
+			{
+				Oid			defTypeId;
+				int32		deftypmod;
+				Oid			defCollId;
+
+				/*
+				 * Yes, try to merge the two column definitions. They must
+				 * have the same type, typmod, and collation.
+				 */
+				ereport(NOTICE,
+						(errmsg("merging multiple inherited definitions of column \"%s\"",
+								attributeName)));
+				def = (ColumnDef *) list_nth(inhSchema, exist_attno - 1);
+				typenameTypeIdAndMod(NULL, def->typeName, &defTypeId, &deftypmod);
+				if (defTypeId != attribute->atttypid ||
+					deftypmod != attribute->atttypmod)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("inherited column \"%s\" has a type conflict",
+									attributeName),
+							 errdetail("%s versus %s",
+									   format_type_with_typemod(defTypeId,
+																deftypmod),
+									   format_type_with_typemod(attribute->atttypid,
+																attribute->atttypmod))));
+				defCollId = GetColumnDefCollation(NULL, def, defTypeId);
+				if (defCollId != attribute->attcollation)
+					ereport(ERROR,
+							(errcode(ERRCODE_COLLATION_MISMATCH),
+							 errmsg("inherited column \"%s\" has a collation conflict",
+									attributeName),
+							 errdetail("\"%s\" versus \"%s\"",
+									   get_collation_name(defCollId),
+									   get_collation_name(attribute->attcollation))));
+
+				/* Copy/check storage parameter */
+				if (def->storage == 0)
+					def->storage = attribute->attstorage;
+				else if (def->storage != attribute->attstorage)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("inherited column \"%s\" has a storage parameter conflict",
+									attributeName),
+							 errdetail("%s versus %s",
+									   storage_name(def->storage),
+									   storage_name(attribute->attstorage))));
+
+				/* Copy/check compression parameter */
+				if (CompressionMethodIsValid(attribute->attcompression))
+				{
+					const char *compression =
+					GetCompressionMethodName(attribute->attcompression);
+
+					if (def->compression == NULL)
+						def->compression = pstrdup(compression);
+					else if (strcmp(def->compression, compression) != 0)
+						ereport(ERROR,
+								(errcode(ERRCODE_DATATYPE_MISMATCH),
+								 errmsg("column \"%s\" has a compression method conflict",
+										attributeName),
+								 errdetail("%s versus %s", def->compression, compression)));
+				}
+
+				def->inhcount++;
+				/* Merge of NOT NULL constraints = OR 'em together */
+				def->is_not_null |= attribute->attnotnull;
+				/* Default and other constraints are handled below */
+				newattmap->attnums[parent_attno - 1] = exist_attno;
+
+				/* Check for GENERATED conflicts */
+				if (def->generated != attribute->attgenerated)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("inherited column \"%s\" has a generation conflict",
+									attributeName)));
+			}
+			else
+			{
+				/*
+				 * No, create a new inherited column
+				 */
+				def = makeNode(ColumnDef);
+				def->colname = pstrdup(attributeName);
+				def->typeName = makeTypeNameFromOid(attribute->atttypid,
+													attribute->atttypmod);
+				def->inhcount = 1;
+				def->is_local = false;
+				def->is_not_null = attribute->attnotnull;
+				def->is_from_type = false;
+				def->storage = attribute->attstorage;
+				def->raw_default = NULL;
+				def->cooked_default = NULL;
+				def->generated = attribute->attgenerated;
+				def->collClause = NULL;
+				def->collOid = attribute->attcollation;
+				def->constraints = NIL;
+				def->location = -1;
+				if (CompressionMethodIsValid(attribute->attcompression))
+					def->compression =
+						pstrdup(GetCompressionMethodName(attribute->attcompression));
+				else
+					def->compression = NULL;
+				inhSchema = lappend(inhSchema, def);
+				newattmap->attnums[parent_attno - 1] = ++child_attno;
+			}
+
+			/*
+			 * Locate default if any
+			 */
+			if (attribute->atthasdef)
+			{
+				Node	   *this_default = NULL;
+
+				/* Find default in constraint structure */
+				if (constr != NULL)
+				{
+					AttrDefault *attrdef = constr->defval;
+
+					for (int i = 0; i < constr->num_defval; i++)
+					{
+						if (attrdef[i].adnum == parent_attno)
+						{
+							this_default = stringToNode(attrdef[i].adbin);
+							break;
+						}
+					}
+				}
+				if (this_default == NULL)
+					elog(ERROR, "default expression not found for attribute %d of relation \"%s\"",
+						 parent_attno, RelationGetRelationName(relation));
+
+				/*
+				 * If it's a GENERATED default, it might contain Vars that
+				 * need to be mapped to the inherited column(s)' new numbers.
+				 * We can't do that till newattmap is ready, so just remember
+				 * all the inherited default expressions for the moment.
+				 */
+				inherited_defaults = lappend(inherited_defaults, this_default);
+				cols_with_defaults = lappend(cols_with_defaults, def);
+			}
+		}
+
+		/*
+		 * Now process any inherited default expressions, adjusting attnos
+		 * using the completed newattmap map.
+		 */
+		forboth(lc1, inherited_defaults, lc2, cols_with_defaults)
+		{
+			Node	   *this_default = (Node *) lfirst(lc1);
+			ColumnDef  *def = (ColumnDef *) lfirst(lc2);
+			bool		found_whole_row;
+
+			/* Adjust Vars to match new table's column numbering */
+			this_default = map_variable_attnos(this_default,
+											   1, 0,
+											   newattmap,
+											   InvalidOid, &found_whole_row);
+
+			/*
+			 * For the moment we have to reject whole-row variables.  We could
+			 * convert them, if we knew the new table's rowtype OID, but that
+			 * hasn't been assigned yet.  (A variable could only appear in a
+			 * generation expression, so the error message is correct.)
+			 */
+			if (found_whole_row)
+				ereport(ERROR,
+						(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+						 errmsg("cannot convert whole-row table reference"),
+						 errdetail("Generation expression for column \"%s\" contains a whole-row reference to table \"%s\".",
+								   def->colname,
+								   RelationGetRelationName(relation))));
+
+			/*
+			 * If we already had a default from some prior parent, check to
+			 * see if they are the same.  If so, no problem; if not, mark the
+			 * column as having a bogus default.  Below, we will complain if
+			 * the bogus default isn't overridden by the child schema.
+			 */
+			Assert(def->raw_default == NULL);
+			if (def->cooked_default == NULL)
+				def->cooked_default = this_default;
+			else if (!equal(def->cooked_default, this_default))
+			{
+				def->cooked_default = &bogus_marker;
+				have_bogus_defaults = true;
+			}
+		}
+
+		/*
+		 * Now copy the CHECK constraints of this parent, adjusting attnos
+		 * using the completed newattmap map.  Identically named constraints
+		 * are merged if possible, else we throw error.
+		 */
+		if (constr && constr->num_check > 0)
+		{
+			ConstrCheck *check = constr->check;
+			int			i;
+
+			for (i = 0; i < constr->num_check; i++)
+			{
+				char	   *name = check[i].ccname;
+				Node	   *expr;
+				bool		found_whole_row;
+
+				/* ignore if the constraint is non-inheritable */
+				if (check[i].ccnoinherit)
+					continue;
+
+				/* Adjust Vars to match new table's column numbering */
+				expr = map_variable_attnos(stringToNode(check[i].ccbin),
+										   1, 0,
+										   newattmap,
+										   InvalidOid, &found_whole_row);
+
+				/*
+				 * For the moment we have to reject whole-row variables. We
+				 * could convert them, if we knew the new table's rowtype OID,
+				 * but that hasn't been assigned yet.
+				 */
+				if (found_whole_row)
+					ereport(ERROR,
+							(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+							 errmsg("cannot convert whole-row table reference"),
+							 errdetail("Constraint \"%s\" contains a whole-row reference to table \"%s\".",
+									   name,
+									   RelationGetRelationName(relation))));
+
+				/* check for duplicate */
+				if (!MergeCheckConstraint(constraints, name, expr))
+				{
+					/* nope, this is a new one */
+					CookedConstraint *cooked;
+
+					cooked = (CookedConstraint *) palloc(sizeof(CookedConstraint));
+					cooked->contype = CONSTR_CHECK;
+					cooked->conoid = InvalidOid;	/* until created */
+					cooked->name = pstrdup(name);
+					cooked->attnum = 0; /* not used for constraints */
+					cooked->expr = expr;
+					cooked->skip_validation = false;
+					cooked->is_local = false;
+					cooked->inhcount = 1;
+					cooked->is_no_inherit = false;
+					constraints = lappend(constraints, cooked);
+				}
+			}
+		}
+
+		free_attrmap(newattmap);
+
+		/*
+		 * Close the parent rel, but keep our lock on it until xact commit.
+		 * That will prevent someone else from deleting or ALTERing the parent
+		 * before the child is committed.
+		 */
+		table_close(relation, NoLock);
+	}
+
+	/*
+	 * If we had no inherited attributes, the result schema is just the
+	 * explicitly declared columns.  Otherwise, we need to merge the declared
+	 * columns into the inherited schema list.  Although, we never have any
+	 * explicitly declared columns if the table is a partition.
+	 */
+	if (inhSchema != NIL)
+	{
+		int			schema_attno = 0;
+
+		foreach(entry, schema)
+		{
+			ColumnDef  *newdef = lfirst(entry);
+			char	   *attributeName = newdef->colname;
+			int			exist_attno;
+
+			schema_attno++;
+
+			/*
+			 * Does it conflict with some previously inherited column?
+			 */
+			exist_attno = findAttrByName(attributeName, inhSchema);
+			if (exist_attno > 0)
+			{
+				ColumnDef  *def;
+				Oid			defTypeId,
+							newTypeId;
+				int32		deftypmod,
+							newtypmod;
+				Oid			defcollid,
+							newcollid;
+
+				/*
+				 * Partitions have only one parent and have no column
+				 * definitions of their own, so conflict should never occur.
+				 */
+				Assert(!is_partition);
+
+				/*
+				 * Yes, try to merge the two column definitions. They must
+				 * have the same type, typmod, and collation.
+				 */
+				if (exist_attno == schema_attno)
+					ereport(NOTICE,
+							(errmsg("merging column \"%s\" with inherited definition",
+									attributeName)));
+				else
+					ereport(NOTICE,
+							(errmsg("moving and merging column \"%s\" with inherited definition", attributeName),
+							 errdetail("User-specified column moved to the position of the inherited column.")));
+				def = (ColumnDef *) list_nth(inhSchema, exist_attno - 1);
+				typenameTypeIdAndMod(NULL, def->typeName, &defTypeId, &deftypmod);
+				typenameTypeIdAndMod(NULL, newdef->typeName, &newTypeId, &newtypmod);
+				if (defTypeId != newTypeId || deftypmod != newtypmod)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("column \"%s\" has a type conflict",
+									attributeName),
+							 errdetail("%s versus %s",
+									   format_type_with_typemod(defTypeId,
+																deftypmod),
+									   format_type_with_typemod(newTypeId,
+																newtypmod))));
+				defcollid = GetColumnDefCollation(NULL, def, defTypeId);
+				newcollid = GetColumnDefCollation(NULL, newdef, newTypeId);
+				if (defcollid != newcollid)
+					ereport(ERROR,
+							(errcode(ERRCODE_COLLATION_MISMATCH),
+							 errmsg("column \"%s\" has a collation conflict",
+									attributeName),
+							 errdetail("\"%s\" versus \"%s\"",
+									   get_collation_name(defcollid),
+									   get_collation_name(newcollid))));
+
+				/*
+				 * Identity is never inherited.  The new column can have an
+				 * identity definition, so we always just take that one.
+				 */
+				def->identity = newdef->identity;
+
+				/* Copy storage parameter */
+				if (def->storage == 0)
+					def->storage = newdef->storage;
+				else if (newdef->storage != 0 && def->storage != newdef->storage)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("column \"%s\" has a storage parameter conflict",
+									attributeName),
+							 errdetail("%s versus %s",
+									   storage_name(def->storage),
+									   storage_name(newdef->storage))));
+
+				/* Copy compression parameter */
+				if (def->compression == NULL)
+					def->compression = newdef->compression;
+				else if (newdef->compression != NULL)
+				{
+					if (strcmp(def->compression, newdef->compression) != 0)
+						ereport(ERROR,
+								(errcode(ERRCODE_DATATYPE_MISMATCH),
+								 errmsg("column \"%s\" has a compression method conflict",
+										attributeName),
+								 errdetail("%s versus %s", def->compression, newdef->compression)));
+				}
+
+				/* Mark the column as locally defined */
+				def->is_local = true;
+				/* Merge of NOT NULL constraints = OR 'em together */
+				def->is_not_null |= newdef->is_not_null;
+
+				/*
+				 * Check for conflicts related to generated columns.
+				 *
+				 * If the parent column is generated, the child column must be
+				 * unadorned and will be made a generated column.  (We could
+				 * in theory allow the child column definition specifying the
+				 * exact same generation expression, but that's a bit
+				 * complicated to implement and doesn't seem very useful.)  We
+				 * also check that the child column doesn't specify a default
+				 * value or identity, which matches the rules for a single
+				 * column in parse_util.c.
+				 */
+				if (def->generated)
+				{
+					if (newdef->generated)
+						ereport(ERROR,
+								(errcode(ERRCODE_INVALID_COLUMN_DEFINITION),
+								 errmsg("child column \"%s\" specifies generation expression",
+										def->colname),
+								 errhint("Omit the generation expression in the definition of the child table column to inherit the generation expression from the parent table.")));
+					if (newdef->raw_default && !newdef->generated)
+						ereport(ERROR,
+								(errcode(ERRCODE_INVALID_COLUMN_DEFINITION),
+								 errmsg("column \"%s\" inherits from generated column but specifies default",
+										def->colname)));
+					if (newdef->identity)
+						ereport(ERROR,
+								(errcode(ERRCODE_INVALID_COLUMN_DEFINITION),
+								 errmsg("column \"%s\" inherits from generated column but specifies identity",
+										def->colname)));
+				}
+
+				/*
+				 * If the parent column is not generated, then take whatever
+				 * the child column definition says.
+				 */
+				else
+				{
+					if (newdef->generated)
+						def->generated = newdef->generated;
+				}
+
+				/* If new def has a default, override previous default */
+				if (newdef->raw_default != NULL)
+				{
+					def->raw_default = newdef->raw_default;
+					def->cooked_default = newdef->cooked_default;
+				}
+			}
+			else
+			{
+				/*
+				 * No, attach new column to result schema
+				 */
+				inhSchema = lappend(inhSchema, newdef);
+			}
+		}
+
+		schema = inhSchema;
+
+		/*
+		 * Check that we haven't exceeded the legal # of columns after merging
+		 * in inherited columns.
+		 */
+		if (list_length(schema) > MaxHeapAttributeNumber)
+			ereport(ERROR,
+					(errcode(ERRCODE_TOO_MANY_COLUMNS),
+					 errmsg("tables can have at most %d columns",
+							MaxHeapAttributeNumber)));
+	}
+
+	/*
+	 * Now that we have the column definition list for a partition, we can
+	 * check whether the columns referenced in the column constraint specs
+	 * actually exist.  Also, we merge NOT NULL and defaults into each
+	 * corresponding column definition.
+	 */
+	if (is_partition)
+	{
+		foreach(entry, saved_schema)
+		{
+			ColumnDef  *restdef = lfirst(entry);
+			bool		found = false;
+			ListCell   *l;
+
+			foreach(l, schema)
+			{
+				ColumnDef  *coldef = lfirst(l);
+
+				if (strcmp(coldef->colname, restdef->colname) == 0)
+				{
+					found = true;
+					coldef->is_not_null |= restdef->is_not_null;
+
+					/*
+					 * Override the parent's default value for this column
+					 * (coldef->cooked_default) with the partition's local
+					 * definition (restdef->raw_default), if there's one. It
+					 * should be physically impossible to get a cooked default
+					 * in the local definition or a raw default in the
+					 * inherited definition, but make sure they're nulls, for
+					 * future-proofing.
+					 */
+					Assert(restdef->cooked_default == NULL);
+					Assert(coldef->raw_default == NULL);
+					if (restdef->raw_default)
+					{
+						coldef->raw_default = restdef->raw_default;
+						coldef->cooked_default = NULL;
+					}
+				}
+			}
+
+			/* complain for constraints on columns not in parent */
+			if (!found)
+				ereport(ERROR,
+						(errcode(ERRCODE_UNDEFINED_COLUMN),
+						 errmsg("column \"%s\" does not exist",
+								restdef->colname)));
+		}
+	}
+
+	/*
+	 * If we found any conflicting parent default values, check to make sure
+	 * they were overridden by the child.
+	 */
+	if (have_bogus_defaults)
+	{
+		foreach(entry, schema)
+		{
+			ColumnDef  *def = lfirst(entry);
+
+			if (def->cooked_default == &bogus_marker)
+			{
+				if (def->generated)
+					ereport(ERROR,
+							(errcode(ERRCODE_INVALID_COLUMN_DEFINITION),
+							 errmsg("column \"%s\" inherits conflicting generation expressions",
+									def->colname)));
+				else
+					ereport(ERROR,
+							(errcode(ERRCODE_INVALID_COLUMN_DEFINITION),
+							 errmsg("column \"%s\" inherits conflicting default values",
+									def->colname),
+							 errhint("To resolve the conflict, specify a default explicitly.")));
+			}
+		}
+	}
+
+	*supconstr = constraints;
+	return schema;
+}
+
+
+/*
+ * MergeCheckConstraint
+ *		Try to merge an inherited CHECK constraint with previous ones
+ *
+ * If we inherit identically-named constraints from multiple parents, we must
+ * merge them, or throw an error if they don't have identical definitions.
+ *
+ * constraints is a list of CookedConstraint structs for previous constraints.
+ *
+ * Returns true if merged (constraint is a duplicate), or false if it's
+ * got a so-far-unique name, or throws error if conflict.
+ */
+static bool
+MergeCheckConstraint(List *constraints, char *name, Node *expr)
+{
+	ListCell   *lc;
+
+	foreach(lc, constraints)
+	{
+		CookedConstraint *ccon = (CookedConstraint *) lfirst(lc);
+
+		Assert(ccon->contype == CONSTR_CHECK);
+
+		/* Non-matching names never conflict */
+		if (strcmp(ccon->name, name) != 0)
+			continue;
+
+		if (equal(expr, ccon->expr))
+		{
+			/* OK to merge */
+			ccon->inhcount++;
+			return true;
+		}
+
+		ereport(ERROR,
+				(errcode(ERRCODE_DUPLICATE_OBJECT),
+				 errmsg("check constraint name \"%s\" appears multiple times but with different expressions",
+						name)));
+	}
+
+	return false;
+}
+
+
+/*
+ * StoreCatalogInheritance
+ *		Updates the system catalogs with proper inheritance information.
+ *
+ * supers is a list of the OIDs of the new relation's direct ancestors.
+ */
+static void
+StoreCatalogInheritance(Oid relationId, List *supers,
+						bool child_is_partition)
+{
+	Relation	relation;
+	int32		seqNumber;
+	ListCell   *entry;
+
+	/*
+	 * sanity checks
+	 */
+	AssertArg(OidIsValid(relationId));
+
+	if (supers == NIL)
+		return;
+
+	/*
+	 * Store INHERITS information in pg_inherits using direct ancestors only.
+	 * Also enter dependencies on the direct ancestors, and make sure they are
+	 * marked with relhassubclass = true.
+	 *
+	 * (Once upon a time, both direct and indirect ancestors were found here
+	 * and then entered into pg_ipl.  Since that catalog doesn't exist
+	 * anymore, there's no need to look for indirect ancestors.)
+	 */
+	relation = table_open(InheritsRelationId, RowExclusiveLock);
+
+	seqNumber = 1;
+	foreach(entry, supers)
+	{
+		Oid			parentOid = lfirst_oid(entry);
+
+		StoreCatalogInheritance1(relationId, parentOid, seqNumber, relation,
+								 child_is_partition);
+		seqNumber++;
+	}
+
+	table_close(relation, RowExclusiveLock);
+}
+
+/*
+ * Make catalog entries showing relationId as being an inheritance child
+ * of parentOid.  inhRelation is the already-opened pg_inherits catalog.
+ */
+static void
+StoreCatalogInheritance1(Oid relationId, Oid parentOid,
+						 int32 seqNumber, Relation inhRelation,
+						 bool child_is_partition)
+{
+	ObjectAddress childobject,
+				parentobject;
+
+	/* store the pg_inherits row */
+	StoreSingleInheritance(relationId, parentOid, seqNumber);
+
+	/*
+	 * Store a dependency too
+	 */
+	parentobject.classId = RelationRelationId;
+	parentobject.objectId = parentOid;
+	parentobject.objectSubId = 0;
+	childobject.classId = RelationRelationId;
+	childobject.objectId = relationId;
+	childobject.objectSubId = 0;
+
+	recordDependencyOn(&childobject, &parentobject,
+					   child_dependency_type(child_is_partition));
+
+	/*
+	 * Post creation hook of this inheritance. Since object_access_hook
+	 * doesn't take multiple object identifiers, we relay oid of parent
+	 * relation using auxiliary_id argument.
+	 */
+	InvokeObjectPostAlterHookArg(InheritsRelationId,
+								 relationId, 0,
+								 parentOid, false);
+
+	/*
+	 * Mark the parent as having subclasses.
+	 */
+	SetRelationHasSubclass(parentOid, true);
+}
+
+/*
+ * Look for an existing schema entry with the given name.
+ *
+ * Returns the index (starting with 1) if attribute already exists in schema,
+ * 0 if it doesn't.
+ */
+static int
+findAttrByName(const char *attributeName, List *schema)
+{
+	ListCell   *s;
+	int			i = 1;
+
+	foreach(s, schema)
+	{
+		ColumnDef  *def = lfirst(s);
+
+		if (strcmp(attributeName, def->colname) == 0)
+			return i;
+
+		i++;
+	}
+	return 0;
+}
+
+
+/*
+ * SetRelationHasSubclass
+ *		Set the value of the relation's relhassubclass field in pg_class.
+ *
+ * NOTE: caller must be holding an appropriate lock on the relation.
+ * ShareUpdateExclusiveLock is sufficient.
+ *
+ * NOTE: an important side-effect of this operation is that an SI invalidation
+ * message is sent out to all backends --- including me --- causing plans
+ * referencing the relation to be rebuilt with the new list of children.
+ * This must happen even if we find that no change is needed in the pg_class
+ * row.
+ */
+void
+SetRelationHasSubclass(Oid relationId, bool relhassubclass)
+{
+	Relation	relationRelation;
+	HeapTuple	tuple;
+	Form_pg_class classtuple;
+
+	/*
+	 * Fetch a modifiable copy of the tuple, modify it, update pg_class.
+	 */
+	relationRelation = table_open(RelationRelationId, RowExclusiveLock);
+	tuple = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(relationId));
+	if (!HeapTupleIsValid(tuple))
+		elog(ERROR, "cache lookup failed for relation %u", relationId);
+	classtuple = (Form_pg_class) GETSTRUCT(tuple);
+
+	if (classtuple->relhassubclass != relhassubclass)
+	{
+		classtuple->relhassubclass = relhassubclass;
+		CatalogTupleUpdate(relationRelation, &tuple->t_self, tuple);
+	}
+	else
+	{
+		/* no need to change tuple, but force relcache rebuild anyway */
+		CacheInvalidateRelcacheByTuple(tuple);
+	}
+
+	heap_freetuple(tuple);
+	table_close(relationRelation, RowExclusiveLock);
+}
+
+/*
+ * CheckRelationTableSpaceMove
+ *		Check if relation can be moved to new tablespace.
+ *
+ * NOTE: The caller must hold AccessExclusiveLock on the relation.
+ *
+ * Returns true if the relation can be moved to the new tablespace; raises
+ * an error if it is not possible to do the move; returns false if the move
+ * would have no effect.
+ */
+bool
+CheckRelationTableSpaceMove(Relation rel, Oid newTableSpaceId)
+{
+	Oid			oldTableSpaceId;
+
+	/*
+	 * No work if no change in tablespace.  Note that MyDatabaseTableSpace is
+	 * stored as 0.
+	 */
+	oldTableSpaceId = rel->rd_rel->reltablespace;
+	if (newTableSpaceId == oldTableSpaceId ||
+		(newTableSpaceId == MyDatabaseTableSpace && oldTableSpaceId == 0))
+		return false;
+
+	/*
+	 * We cannot support moving mapped relations into different tablespaces.
+	 * (In particular this eliminates all shared catalogs.)
+	 */
+	if (RelationIsMapped(rel))
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("cannot move system relation \"%s\"",
+						RelationGetRelationName(rel))));
+
+	/* Cannot move a non-shared relation into pg_global */
+	if (newTableSpaceId == GLOBALTABLESPACE_OID)
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("only shared relations can be placed in pg_global tablespace")));
+
+	/*
+	 * Do not allow moving temp tables of other backends ... their local
+	 * buffer manager is not going to cope.
+	 */
+	if (RELATION_IS_OTHER_TEMP(rel))
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("cannot move temporary tables of other sessions")));
+
+	return true;
+}
+
+/*
+ * SetRelationTableSpace
+ *		Set new reltablespace and relfilenode in pg_class entry.
+ *
+ * newTableSpaceId is the new tablespace for the relation, and
+ * newRelFileNode its new filenode.  If newRelFileNode is InvalidOid,
+ * this field is not updated.
+ *
+ * NOTE: The caller must hold AccessExclusiveLock on the relation.
+ *
+ * The caller of this routine had better check if a relation can be
+ * moved to this new tablespace by calling CheckRelationTableSpaceMove()
+ * first, and is responsible for making the change visible with
+ * CommandCounterIncrement().
+ */
+void
+SetRelationTableSpace(Relation rel,
+					  Oid newTableSpaceId,
+					  Oid newRelFileNode)
+{
+	Relation	pg_class;
+	HeapTuple	tuple;
+	Form_pg_class rd_rel;
+	Oid			reloid = RelationGetRelid(rel);
+
+	Assert(CheckRelationTableSpaceMove(rel, newTableSpaceId));
+
+	/* Get a modifiable copy of the relation's pg_class row. */
+	pg_class = table_open(RelationRelationId, RowExclusiveLock);
+
+	tuple = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(reloid));
+	if (!HeapTupleIsValid(tuple))
+		elog(ERROR, "cache lookup failed for relation %u", reloid);
+	rd_rel = (Form_pg_class) GETSTRUCT(tuple);
+
+	/* Update the pg_class row. */
+	rd_rel->reltablespace = (newTableSpaceId == MyDatabaseTableSpace) ?
+		InvalidOid : newTableSpaceId;
+	if (OidIsValid(newRelFileNode))
+		rd_rel->relfilenode = newRelFileNode;
+	CatalogTupleUpdate(pg_class, &tuple->t_self, tuple);
+
+	/*
+	 * Record dependency on tablespace.  This is only required for relations
+	 * that have no physical storage.
+	 */
+	if (!RELKIND_HAS_STORAGE(rel->rd_rel->relkind))
+		changeDependencyOnTablespace(RelationRelationId, reloid,
+									 rd_rel->reltablespace);
+
+	heap_freetuple(tuple);
+	table_close(pg_class, RowExclusiveLock);
+}
+
+/*
+ *		renameatt_check			- basic sanity checks before attribute rename
+ */
+static void
+renameatt_check(Oid myrelid, Form_pg_class classform, bool recursing)
+{
+	char		relkind = classform->relkind;
+
+	if (classform->reloftype && !recursing)
+		ereport(ERROR,
+				(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+				 errmsg("cannot rename column of typed table")));
+
+	/*
+	 * Renaming the columns of sequences or toast tables doesn't actually
+	 * break anything from the system's point of view, since internal
+	 * references are by attnum.  But it doesn't seem right to allow users to
+	 * change names that are hardcoded into the system, hence the following
+	 * restriction.
+	 */
+	if (relkind != RELKIND_RELATION &&
+		relkind != RELKIND_VIEW &&
+		relkind != RELKIND_MATVIEW &&
+		relkind != RELKIND_COMPOSITE_TYPE &&
+		relkind != RELKIND_INDEX &&
+		relkind != RELKIND_PARTITIONED_INDEX &&
+		relkind != RELKIND_FOREIGN_TABLE &&
+		relkind != RELKIND_PARTITIONED_TABLE)
+		ereport(ERROR,
+				(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+				 errmsg("cannot rename columns of relation \"%s\"",
+						NameStr(classform->relname)),
+				 errdetail_relkind_not_supported(relkind)));
+
+	/*
+	 * permissions checking.  only the owner of a class can change its schema.
+	 */
+	if (!pg_class_ownercheck(myrelid, GetUserId()))
+		aclcheck_error(ACLCHECK_NOT_OWNER, get_relkind_objtype(get_rel_relkind(myrelid)),
+					   NameStr(classform->relname));
+	if (!allowSystemTableMods && IsSystemClass(myrelid, classform))
+		ereport(ERROR,
+				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
+				 errmsg("permission denied: \"%s\" is a system catalog",
+						NameStr(classform->relname))));
+}
+
+/*
+ *		renameatt_internal		- workhorse for renameatt
+ *
+ * Return value is the attribute number in the 'myrelid' relation.
+ */
+static AttrNumber
+renameatt_internal(Oid myrelid,
+				   const char *oldattname,
+				   const char *newattname,
+				   bool recurse,
+				   bool recursing,
+				   int expected_parents,
+				   DropBehavior behavior)
+{
+	Relation	targetrelation;
+	Relation	attrelation;
+	HeapTuple	atttup;
+	Form_pg_attribute attform;
+	AttrNumber	attnum;
+
+	/*
+	 * Grab an exclusive lock on the target table, which we will NOT release
+	 * until end of transaction.
+	 */
+	targetrelation = relation_open(myrelid, AccessExclusiveLock);
+	renameatt_check(myrelid, RelationGetForm(targetrelation), recursing);
+
+	/*
+	 * if the 'recurse' flag is set then we are supposed to rename this
+	 * attribute in all classes that inherit from 'relname' (as well as in
+	 * 'relname').
+	 *
+	 * any permissions or problems with duplicate attributes will cause the
+	 * whole transaction to abort, which is what we want -- all or nothing.
+	 */
+	if (recurse)
+	{
+		List	   *child_oids,
+				   *child_numparents;
+		ListCell   *lo,
+				   *li;
+
+		/*
+		 * we need the number of parents for each child so that the recursive
+		 * calls to renameatt() can determine whether there are any parents
+		 * outside the inheritance hierarchy being processed.
+		 */
+		child_oids = find_all_inheritors(myrelid, AccessExclusiveLock,
+										 &child_numparents);
+
+		/*
+		 * find_all_inheritors does the recursive search of the inheritance
+		 * hierarchy, so all we have to do is process all of the relids in the
+		 * list that it returns.
+		 */
+		forboth(lo, child_oids, li, child_numparents)
+		{
+			Oid			childrelid = lfirst_oid(lo);
+			int			numparents = lfirst_int(li);
+
+			if (childrelid == myrelid)
+				continue;
+			/* note we need not recurse again */
+			renameatt_internal(childrelid, oldattname, newattname, false, true, numparents, behavior);
+		}
+	}
+	else
+	{
+		/*
+		 * If we are told not to recurse, there had better not be any child
+		 * tables; else the rename would put them out of step.
+		 *
+		 * expected_parents will only be 0 if we are not already recursing.
+		 */
+		if (expected_parents == 0 &&
+			find_inheritance_children(myrelid, NoLock) != NIL)
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
+					 errmsg("inherited column \"%s\" must be renamed in child tables too",
+							oldattname)));
+	}
+
+	/* rename attributes in typed tables of composite type */
+	if (targetrelation->rd_rel->relkind == RELKIND_COMPOSITE_TYPE)
+	{
+		List	   *child_oids;
+		ListCell   *lo;
+
+		child_oids = find_typed_table_dependencies(targetrelation->rd_rel->reltype,
+												   RelationGetRelationName(targetrelation),
+												   behavior);
+
+		foreach(lo, child_oids)
+			renameatt_internal(lfirst_oid(lo), oldattname, newattname, true, true, 0, behavior);
+	}
+
+	attrelation = table_open(AttributeRelationId, RowExclusiveLock);
+
+	atttup = SearchSysCacheCopyAttName(myrelid, oldattname);
+	if (!HeapTupleIsValid(atttup))
+		ereport(ERROR,
+				(errcode(ERRCODE_UNDEFINED_COLUMN),
+				 errmsg("column \"%s\" does not exist",
+						oldattname)));
+	attform = (Form_pg_attribute) GETSTRUCT(atttup);
+
+	attnum = attform->attnum;
+	if (attnum <= 0)
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("cannot rename system column \"%s\"",
+						oldattname)));
+
+	/*
+	 * if the attribute is inherited, forbid the renaming.  if this is a
+	 * top-level call to renameatt(), then expected_parents will be 0, so the
+	 * effect of this code will be to prohibit the renaming if the attribute
+	 * is inherited at all.  if this is a recursive call to renameatt(),
+	 * expected_parents will be the number of parents the current relation has
+	 * within the inheritance hierarchy being processed, so we'll prohibit the
+	 * renaming only if there are additional parents from elsewhere.
+	 */
+	if (attform->attinhcount > expected_parents)
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
+				 errmsg("cannot rename inherited column \"%s\"",
+						oldattname)));
+
+	/* new name should not already exist */
+	(void) check_for_column_name_collision(targetrelation, newattname, false);
+
+	/* apply the update */
+	namestrcpy(&(attform->attname), newattname);
+
+	CatalogTupleUpdate(attrelation, &atttup->t_self, atttup);
+
+	InvokeObjectPostAlterHook(RelationRelationId, myrelid, attnum);
+
+	heap_freetuple(atttup);
+
+	table_close(attrelation, RowExclusiveLock);
+
+	relation_close(targetrelation, NoLock); /* close rel but keep lock */
+
+	return attnum;
+}
+
+/*
+ * Perform permissions and integrity checks before acquiring a relation lock.
+ */
+static void
+RangeVarCallbackForRenameAttribute(const RangeVar *rv, Oid relid, Oid oldrelid,
+								   void *arg)
+{
+	HeapTuple	tuple;
+	Form_pg_class form;
+
+	tuple = SearchSysCache1(RELOID, ObjectIdGetDatum(relid));
+	if (!HeapTupleIsValid(tuple))
+		return;					/* concurrently dropped */
+	form = (Form_pg_class) GETSTRUCT(tuple);
+	renameatt_check(relid, form, false);
+	ReleaseSysCache(tuple);
+}
+
+/*
+ *		renameatt		- changes the name of an attribute in a relation
+ *
+ * The returned ObjectAddress is that of the renamed column.
+ */
+ObjectAddress
+renameatt(RenameStmt *stmt)
+{
+	Oid			relid;
+	AttrNumber	attnum;
+	ObjectAddress address;
+
+	/* lock level taken here should match renameatt_internal */
+	relid = RangeVarGetRelidExtended(stmt->relation, AccessExclusiveLock,
+									 stmt->missing_ok ? RVR_MISSING_OK : 0,
+									 RangeVarCallbackForRenameAttribute,
+									 NULL);
+
+	if (!OidIsValid(relid))
+	{
+		ereport(NOTICE,
+				(errmsg("relation \"%s\" does not exist, skipping",
+						stmt->relation->relname)));
+		return InvalidObjectAddress;
+	}
+
+	attnum =
+		renameatt_internal(relid,
+						   stmt->subname,	/* old att name */
+						   stmt->newname,	/* new att name */
+						   stmt->relation->inh, /* recursive? */
+						   false,	/* recursing? */
+						   0,	/* expected inhcount */
+						   stmt->behavior);
+
+	ObjectAddressSubSet(address, RelationRelationId, relid, attnum);
+
+	return address;
+}
+
+/*
+ * same logic as renameatt_internal
+ */
+static ObjectAddress
+rename_constraint_internal(Oid myrelid,
+						   Oid mytypid,
+						   const char *oldconname,
+						   const char *newconname,
+						   bool recurse,
+						   bool recursing,
+						   int expected_parents)
+{
+	Relation	targetrelation = NULL;
+	Oid			constraintOid;
+	HeapTuple	tuple;
+	Form_pg_constraint con;
+	ObjectAddress address;
+
+	AssertArg(!myrelid || !mytypid);
+
+	if (mytypid)
+	{
+		constraintOid = get_domain_constraint_oid(mytypid, oldconname, false);
+	}
+	else
+	{
+		targetrelation = relation_open(myrelid, AccessExclusiveLock);
+
+		/*
+		 * don't tell it whether we're recursing; we allow changing typed
+		 * tables here
+		 */
+		renameatt_check(myrelid, RelationGetForm(targetrelation), false);
+
+		constraintOid = get_relation_constraint_oid(myrelid, oldconname, false);
+	}
+
+	tuple = SearchSysCache1(CONSTROID, ObjectIdGetDatum(constraintOid));
+	if (!HeapTupleIsValid(tuple))
+		elog(ERROR, "cache lookup failed for constraint %u",
+			 constraintOid);
+	con = (Form_pg_constraint) GETSTRUCT(tuple);
+
+	if (myrelid && con->contype == CONSTRAINT_CHECK && !con->connoinherit)
+	{
+		if (recurse)
+		{
+			List	   *child_oids,
+					   *child_numparents;
+			ListCell   *lo,
+					   *li;
+
+			child_oids = find_all_inheritors(myrelid, AccessExclusiveLock,
+											 &child_numparents);
+
+			forboth(lo, child_oids, li, child_numparents)
+			{
+				Oid			childrelid = lfirst_oid(lo);
+				int			numparents = lfirst_int(li);
+
+				if (childrelid == myrelid)
+					continue;
+
+				rename_constraint_internal(childrelid, InvalidOid, oldconname, newconname, false, true, numparents);
+			}
+		}
+		else
+		{
+			if (expected_parents == 0 &&
+				find_inheritance_children(myrelid, NoLock) != NIL)
+				ereport(ERROR,
+						(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
+						 errmsg("inherited constraint \"%s\" must be renamed in child tables too",
+								oldconname)));
+		}
+
+		if (con->coninhcount > expected_parents)
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
+					 errmsg("cannot rename inherited constraint \"%s\"",
+							oldconname)));
+	}
+
+	if (con->conindid
+		&& (con->contype == CONSTRAINT_PRIMARY
+			|| con->contype == CONSTRAINT_UNIQUE
+			|| con->contype == CONSTRAINT_EXCLUSION))
+		/* rename the index; this renames the constraint as well */
+		RenameRelationInternal(con->conindid, newconname, false, true);
+	else
+		RenameConstraintById(constraintOid, newconname);
+
+	ObjectAddressSet(address, ConstraintRelationId, constraintOid);
+
+	ReleaseSysCache(tuple);
+
+	if (targetrelation)
+	{
+		/*
+		 * Invalidate relcache so as others can see the new constraint name.
+		 */
+		CacheInvalidateRelcache(targetrelation);
+
+		relation_close(targetrelation, NoLock); /* close rel but keep lock */
+	}
+
+	return address;
+}
+
+ObjectAddress
+RenameConstraint(RenameStmt *stmt)
+{
+	Oid			relid = InvalidOid;
+	Oid			typid = InvalidOid;
+
+	if (stmt->renameType == OBJECT_DOMCONSTRAINT)
+	{
+		Relation	rel;
+		HeapTuple	tup;
+
+		typid = typenameTypeId(NULL, makeTypeNameFromNameList(castNode(List, stmt->object)));
+		rel = table_open(TypeRelationId, RowExclusiveLock);
+		tup = SearchSysCache1(TYPEOID, ObjectIdGetDatum(typid));
+		if (!HeapTupleIsValid(tup))
+			elog(ERROR, "cache lookup failed for type %u", typid);
+		checkDomainOwner(tup);
+		ReleaseSysCache(tup);
+		table_close(rel, NoLock);
+	}
+	else
+	{
+		/* lock level taken here should match rename_constraint_internal */
+		relid = RangeVarGetRelidExtended(stmt->relation, AccessExclusiveLock,
+										 stmt->missing_ok ? RVR_MISSING_OK : 0,
+										 RangeVarCallbackForRenameAttribute,
+										 NULL);
+		if (!OidIsValid(relid))
+		{
+			ereport(NOTICE,
+					(errmsg("relation \"%s\" does not exist, skipping",
+							stmt->relation->relname)));
+			return InvalidObjectAddress;
+		}
+	}
+
+	return
+		rename_constraint_internal(relid, typid,
+								   stmt->subname,
+								   stmt->newname,
+								   (stmt->relation &&
+									stmt->relation->inh),	/* recursive? */
+								   false,	/* recursing? */
+								   0 /* expected inhcount */ );
+}
+
+/*
+ * Execute ALTER TABLE/INDEX/SEQUENCE/VIEW/MATERIALIZED VIEW/FOREIGN TABLE
+ * RENAME
+ */
+ObjectAddress
+RenameRelation(RenameStmt *stmt)
+{
+	bool		is_index_stmt = stmt->renameType == OBJECT_INDEX;
+	Oid			relid;
+	ObjectAddress address;
+
+	/*
+	 * Grab an exclusive lock on the target table, index, sequence, view,
+	 * materialized view, or foreign table, which we will NOT release until
+	 * end of transaction.
+	 *
+	 * Lock level used here should match RenameRelationInternal, to avoid lock
+	 * escalation.  However, because ALTER INDEX can be used with any relation
+	 * type, we mustn't believe without verification.
+	 */
+	for (;;)
+	{
+		LOCKMODE	lockmode;
+		char		relkind;
+		bool		obj_is_index;
+
+		lockmode = is_index_stmt ? ShareUpdateExclusiveLock : AccessExclusiveLock;
+
+		relid = RangeVarGetRelidExtended(stmt->relation, lockmode,
+										 stmt->missing_ok ? RVR_MISSING_OK : 0,
+										 RangeVarCallbackForAlterRelation,
+										 (void *) stmt);
+
+		if (!OidIsValid(relid))
+		{
+			ereport(NOTICE,
+					(errmsg("relation \"%s\" does not exist, skipping",
+							stmt->relation->relname)));
+			return InvalidObjectAddress;
+		}
+
+		/*
+		 * We allow mismatched statement and object types (e.g., ALTER INDEX
+		 * to rename a table), but we might've used the wrong lock level.  If
+		 * that happens, retry with the correct lock level.  We don't bother
+		 * if we already acquired AccessExclusiveLock with an index, however.
+		 */
+		relkind = get_rel_relkind(relid);
+		obj_is_index = (relkind == RELKIND_INDEX ||
+						relkind == RELKIND_PARTITIONED_INDEX);
+		if (obj_is_index || is_index_stmt == obj_is_index)
+			break;
+
+		UnlockRelationOid(relid, lockmode);
+		is_index_stmt = obj_is_index;
+	}
+
+	/* Do the work */
+	RenameRelationInternal(relid, stmt->newname, false, is_index_stmt);
+
+	ObjectAddressSet(address, RelationRelationId, relid);
+
+	return address;
+}
+
+/*
+ *		RenameRelationInternal - change the name of a relation
+ */
+void
+RenameRelationInternal(Oid myrelid, const char *newrelname, bool is_internal, bool is_index)
+{
+	Relation	targetrelation;
+	Relation	relrelation;	/* for RELATION relation */
+	HeapTuple	reltup;
+	Form_pg_class relform;
+	Oid			namespaceId;
+
+	/*
+	 * Grab a lock on the target relation, which we will NOT release until end
+	 * of transaction.  We need at least a self-exclusive lock so that
+	 * concurrent DDL doesn't overwrite the rename if they start updating
+	 * while still seeing the old version.  The lock also guards against
+	 * triggering relcache reloads in concurrent sessions, which might not
+	 * handle this information changing under them.  For indexes, we can use a
+	 * reduced lock level because RelationReloadIndexInfo() handles indexes
+	 * specially.
+	 */
+	targetrelation = relation_open(myrelid, is_index ? ShareUpdateExclusiveLock : AccessExclusiveLock);
+	namespaceId = RelationGetNamespace(targetrelation);
+
+	/*
+	 * Find relation's pg_class tuple, and make sure newrelname isn't in use.
+	 */
+	relrelation = table_open(RelationRelationId, RowExclusiveLock);
+
+	reltup = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(myrelid));
+	if (!HeapTupleIsValid(reltup))	/* shouldn't happen */
+		elog(ERROR, "cache lookup failed for relation %u", myrelid);
+	relform = (Form_pg_class) GETSTRUCT(reltup);
+
+	if (get_relname_relid(newrelname, namespaceId) != InvalidOid)
+		ereport(ERROR,
+				(errcode(ERRCODE_DUPLICATE_TABLE),
+				 errmsg("relation \"%s\" already exists",
+						newrelname)));
+
+	/*
+	 * RenameRelation is careful not to believe the caller's idea of the
+	 * relation kind being handled.  We don't have to worry about this, but
+	 * let's not be totally oblivious to it.  We can process an index as
+	 * not-an-index, but not the other way around.
+	 */
+	Assert(!is_index ||
+		   is_index == (targetrelation->rd_rel->relkind == RELKIND_INDEX ||
+						targetrelation->rd_rel->relkind == RELKIND_PARTITIONED_INDEX));
+
+	/*
+	 * Update pg_class tuple with new relname.  (Scribbling on reltup is OK
+	 * because it's a copy...)
+	 */
+	namestrcpy(&(relform->relname), newrelname);
+
+	CatalogTupleUpdate(relrelation, &reltup->t_self, reltup);
+
+	InvokeObjectPostAlterHookArg(RelationRelationId, myrelid, 0,
+								 InvalidOid, is_internal);
+
+	heap_freetuple(reltup);
+	table_close(relrelation, RowExclusiveLock);
+
+	/*
+	 * Also rename the associated type, if any.
+	 */
+	if (OidIsValid(targetrelation->rd_rel->reltype))
+		RenameTypeInternal(targetrelation->rd_rel->reltype,
+						   newrelname, namespaceId);
+
+	/*
+	 * Also rename the associated constraint, if any.
+	 */
+	if (targetrelation->rd_rel->relkind == RELKIND_INDEX ||
+		targetrelation->rd_rel->relkind == RELKIND_PARTITIONED_INDEX)
+	{
+		Oid			constraintId = get_index_constraint(myrelid);
+
+		if (OidIsValid(constraintId))
+			RenameConstraintById(constraintId, newrelname);
+	}
+
+	/*
+	 * Close rel, but keep lock!
+	 */
+	relation_close(targetrelation, NoLock);
+}
+
+/*
+ *		ResetRelRewrite - reset relrewrite
+ */
+void
+ResetRelRewrite(Oid myrelid)
+{
+	Relation	relrelation;	/* for RELATION relation */
+	HeapTuple	reltup;
+	Form_pg_class relform;
+
+	/*
+	 * Find relation's pg_class tuple.
+	 */
+	relrelation = table_open(RelationRelationId, RowExclusiveLock);
+
+	reltup = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(myrelid));
+	if (!HeapTupleIsValid(reltup))	/* shouldn't happen */
+		elog(ERROR, "cache lookup failed for relation %u", myrelid);
+	relform = (Form_pg_class) GETSTRUCT(reltup);
+
+	/*
+	 * Update pg_class tuple.
+	 */
+	relform->relrewrite = InvalidOid;
+
+	CatalogTupleUpdate(relrelation, &reltup->t_self, reltup);
+
+	heap_freetuple(reltup);
+	table_close(relrelation, RowExclusiveLock);
+}
+
+/*
+ * Disallow ALTER TABLE (and similar commands) when the current backend has
+ * any open reference to the target table besides the one just acquired by
+ * the calling command; this implies there's an open cursor or active plan.
+ * We need this check because our lock doesn't protect us against stomping
+ * on our own foot, only other people's feet!
+ *
+ * For ALTER TABLE, the only case known to cause serious trouble is ALTER
+ * COLUMN TYPE, and some changes are obviously pretty benign, so this could
+ * possibly be relaxed to only error out for certain types of alterations.
+ * But the use-case for allowing any of these things is not obvious, so we
+ * won't work hard at it for now.
+ *
+ * We also reject these commands if there are any pending AFTER trigger events
+ * for the rel.  This is certainly necessary for the rewriting variants of
+ * ALTER TABLE, because they don't preserve tuple TIDs and so the pending
+ * events would try to fetch the wrong tuples.  It might be overly cautious
+ * in other cases, but again it seems better to err on the side of paranoia.
+ *
+ * REINDEX calls this with "rel" referencing the index to be rebuilt; here
+ * we are worried about active indexscans on the index.  The trigger-event
+ * check can be skipped, since we are doing no damage to the parent table.
+ *
+ * The statement name (eg, "ALTER TABLE") is passed for use in error messages.
+ */
+void
+CheckTableNotInUse(Relation rel, const char *stmt)
+{
+	int			expected_refcnt;
+
+	expected_refcnt = rel->rd_isnailed ? 2 : 1;
+	if (rel->rd_refcnt != expected_refcnt)
+		ereport(ERROR,
+				(errcode(ERRCODE_OBJECT_IN_USE),
+		/* translator: first %s is a SQL command, eg ALTER TABLE */
+				 errmsg("cannot %s \"%s\" because it is being used by active queries in this session",
+						stmt, RelationGetRelationName(rel))));
+
+	if (rel->rd_rel->relkind != RELKIND_INDEX &&
+		rel->rd_rel->relkind != RELKIND_PARTITIONED_INDEX &&
+		AfterTriggerPendingOnRel(RelationGetRelid(rel)))
+		ereport(ERROR,
+				(errcode(ERRCODE_OBJECT_IN_USE),
+		/* translator: first %s is a SQL command, eg ALTER TABLE */
+				 errmsg("cannot %s \"%s\" because it has pending trigger events",
+						stmt, RelationGetRelationName(rel))));
+}
+
+/*
+ * AlterTableLookupRelation
+ *		Look up, and lock, the OID for the relation named by an alter table
+ *		statement.
+ */
+Oid
+AlterTableLookupRelation(AlterTableStmt *stmt, LOCKMODE lockmode)
+{
+	return RangeVarGetRelidExtended(stmt->relation, lockmode,
+									stmt->missing_ok ? RVR_MISSING_OK : 0,
+									RangeVarCallbackForAlterRelation,
+									(void *) stmt);
+}
+
+/*
+ * AlterTable
+ *		Execute ALTER TABLE, which can be a list of subcommands
+ *
+ * ALTER TABLE is performed in three phases:
+ *		1. Examine subcommands and perform pre-transformation checking.
+ *		2. Validate and transform subcommands, and update system catalogs.
+ *		3. Scan table(s) to check new constraints, and optionally recopy
+ *		   the data into new table(s).
+ * Phase 3 is not performed unless one or more of the subcommands requires
+ * it.  The intention of this design is to allow multiple independent
+ * updates of the table schema to be performed with only one pass over the
+ * data.
+ *
+ * ATPrepCmd performs phase 1.  A "work queue" entry is created for
+ * each table to be affected (there may be multiple affected tables if the
+ * commands traverse a table inheritance hierarchy).  Also we do preliminary
+ * validation of the subcommands.  Because earlier subcommands may change
+ * the catalog state seen by later commands, there are limits to what can
+ * be done in this phase.  Generally, this phase acquires table locks,
+ * checks permissions and relkind, and recurses to find child tables.
+ *
+ * ATRewriteCatalogs performs phase 2 for each affected table.
+ * Certain subcommands need to be performed before others to avoid
+ * unnecessary conflicts; for example, DROP COLUMN should come before
+ * ADD COLUMN.  Therefore phase 1 divides the subcommands into multiple
+ * lists, one for each logical "pass" of phase 2.
+ *
+ * ATRewriteTables performs phase 3 for those tables that need it.
+ *
+ * For most subcommand types, phases 2 and 3 do no explicit recursion,
+ * since phase 1 already does it.  However, for certain subcommand types
+ * it is only possible to determine how to recurse at phase 2 time; for
+ * those cases, phase 1 sets the cmd->recurse flag (or, in some older coding,
+ * changes the command subtype of a "Recurse" variant XXX to be cleaned up.)
+ *
+ * Thanks to the magic of MVCC, an error anywhere along the way rolls back
+ * the whole operation; we don't have to do anything special to clean up.
+ *
+ * The caller must lock the relation, with an appropriate lock level
+ * for the subcommands requested, using AlterTableGetLockLevel(stmt->cmds)
+ * or higher. We pass the lock level down
+ * so that we can apply it recursively to inherited tables. Note that the
+ * lock level we want as we recurse might well be higher than required for
+ * that specific subcommand. So we pass down the overall lock requirement,
+ * rather than reassess it at lower levels.
+ *
+ * The caller also provides a "context" which is to be passed back to
+ * utility.c when we need to execute a subcommand such as CREATE INDEX.
+ * Some of the fields therein, such as the relid, are used here as well.
+ */
+void
+AlterTable(AlterTableStmt *stmt, LOCKMODE lockmode,
+		   AlterTableUtilityContext *context)
+{
+	Relation	rel;
+
+	/* Caller is required to provide an adequate lock. */
+	rel = relation_open(context->relid, NoLock);
+
+	CheckTableNotInUse(rel, "ALTER TABLE");
+
+	ATController(stmt, rel, stmt->cmds, stmt->relation->inh, lockmode, context);
+}
+
+/*
+ * AlterTableInternal
+ *
+ * ALTER TABLE with target specified by OID
+ *
+ * We do not reject if the relation is already open, because it's quite
+ * likely that one or more layers of caller have it open.  That means it
+ * is unsafe to use this entry point for alterations that could break
+ * existing query plans.  On the assumption it's not used for such, we
+ * don't have to reject pending AFTER triggers, either.
+ *
+ * Also, since we don't have an AlterTableUtilityContext, this cannot be
+ * used for any subcommand types that require parse transformation or
+ * could generate subcommands that have to be passed to ProcessUtility.
+ */
+void
+AlterTableInternal(Oid relid, List *cmds, bool recurse)
+{
+	Relation	rel;
+	LOCKMODE	lockmode = AlterTableGetLockLevel(cmds);
+
+	rel = relation_open(relid, lockmode);
+
+	EventTriggerAlterTableRelid(relid);
+
+	ATController(NULL, rel, cmds, recurse, lockmode, NULL);
+}
+
+/*
+ * AlterTableGetLockLevel
+ *
+ * Sets the overall lock level required for the supplied list of subcommands.
+ * Policy for doing this set according to needs of AlterTable(), see
+ * comments there for overall explanation.
+ *
+ * Function is called before and after parsing, so it must give same
+ * answer each time it is called. Some subcommands are transformed
+ * into other subcommand types, so the transform must never be made to a
+ * lower lock level than previously assigned. All transforms are noted below.
+ *
+ * Since this is called before we lock the table we cannot use table metadata
+ * to influence the type of lock we acquire.
+ *
+ * There should be no lockmodes hardcoded into the subcommand functions. All
+ * lockmode decisions for ALTER TABLE are made here only. The one exception is
+ * ALTER TABLE RENAME which is treated as a different statement type T_RenameStmt
+ * and does not travel through this section of code and cannot be combined with
+ * any of the subcommands given here.
+ *
+ * Note that Hot Standby only knows about AccessExclusiveLocks on the primary
+ * so any changes that might affect SELECTs running on standbys need to use
+ * AccessExclusiveLocks even if you think a lesser lock would do, unless you
+ * have a solution for that also.
+ *
+ * Also note that pg_dump uses only an AccessShareLock, meaning that anything
+ * that takes a lock less than AccessExclusiveLock can change object definitions
+ * while pg_dump is running. Be careful to check that the appropriate data is
+ * derived by pg_dump using an MVCC snapshot, rather than syscache lookups,
+ * otherwise we might end up with an inconsistent dump that can't restore.
+ */
+LOCKMODE
+AlterTableGetLockLevel(List *cmds)
+{
+	/*
+	 * This only works if we read catalog tables using MVCC snapshots.
+	 */
+	ListCell   *lcmd;
+	LOCKMODE	lockmode = ShareUpdateExclusiveLock;
+
+	foreach(lcmd, cmds)
+	{
+		AlterTableCmd *cmd = (AlterTableCmd *) lfirst(lcmd);
+		LOCKMODE	cmd_lockmode = AccessExclusiveLock; /* default for compiler */
+
+		switch (cmd->subtype)
+		{
+				/*
+				 * These subcommands rewrite the heap, so require full locks.
+				 */
+			case AT_AddColumn:	/* may rewrite heap, in some cases and visible
+								 * to SELECT */
+			case AT_SetAccessMethod:	/* must rewrite heap */
+			case AT_SetTableSpace:	/* must rewrite heap */
+			case AT_AlterColumnType:	/* must rewrite heap */
+				cmd_lockmode = AccessExclusiveLock;
+				break;
+
+				/*
+				 * These subcommands may require addition of toast tables. If
+				 * we add a toast table to a table currently being scanned, we
+				 * might miss data added to the new toast table by concurrent
+				 * insert transactions.
+				 */
+			case AT_SetStorage: /* may add toast tables, see
+								 * ATRewriteCatalogs() */
+				cmd_lockmode = AccessExclusiveLock;
+				break;
+
+				/*
+				 * Removing constraints can affect SELECTs that have been
+				 * optimized assuming the constraint holds true. See also
+				 * CloneFkReferenced.
+				 */
+			case AT_DropConstraint: /* as DROP INDEX */
+			case AT_DropNotNull:	/* may change some SQL plans */
+				cmd_lockmode = AccessExclusiveLock;
+				break;
+
+				/*
+				 * Subcommands that may be visible to concurrent SELECTs
+				 */
+			case AT_DropColumn: /* change visible to SELECT */
+			case AT_AddColumnToView:	/* CREATE VIEW */
+			case AT_DropOids:	/* used to equiv to DropColumn */
+			case AT_EnableAlwaysRule:	/* may change SELECT rules */
+			case AT_EnableReplicaRule:	/* may change SELECT rules */
+			case AT_EnableRule: /* may change SELECT rules */
+			case AT_DisableRule:	/* may change SELECT rules */
+				cmd_lockmode = AccessExclusiveLock;
+				break;
+
+				/*
+				 * Changing owner may remove implicit SELECT privileges
+				 */
+			case AT_ChangeOwner:	/* change visible to SELECT */
+				cmd_lockmode = AccessExclusiveLock;
+				break;
+
+				/*
+				 * Changing foreign table options may affect optimization.
+				 */
+			case AT_GenericOptions:
+			case AT_AlterColumnGenericOptions:
+				cmd_lockmode = AccessExclusiveLock;
+				break;
+
+				/*
+				 * These subcommands affect write operations only.
+				 */
+			case AT_EnableTrig:
+			case AT_EnableAlwaysTrig:
+			case AT_EnableReplicaTrig:
+			case AT_EnableTrigAll:
+			case AT_EnableTrigUser:
+			case AT_DisableTrig:
+			case AT_DisableTrigAll:
+			case AT_DisableTrigUser:
+				cmd_lockmode = ShareRowExclusiveLock;
+				break;
+
+				/*
+				 * These subcommands affect write operations only. XXX
+				 * Theoretically, these could be ShareRowExclusiveLock.
+				 */
+			case AT_ColumnDefault:
+			case AT_CookedColumnDefault:
+			case AT_AlterConstraint:
+			case AT_AddIndex:	/* from ADD CONSTRAINT */
+			case AT_AddIndexConstraint:
+			case AT_ReplicaIdentity:
+			case AT_SetNotNull:
+			case AT_EnableRowSecurity:
+			case AT_DisableRowSecurity:
+			case AT_ForceRowSecurity:
+			case AT_NoForceRowSecurity:
+			case AT_AddIdentity:
+			case AT_DropIdentity:
+			case AT_SetIdentity:
+			case AT_DropExpression:
+			case AT_SetCompression:
+				cmd_lockmode = AccessExclusiveLock;
+				break;
+
+			case AT_AddConstraint:
+			case AT_AddConstraintRecurse:	/* becomes AT_AddConstraint */
+			case AT_ReAddConstraint:	/* becomes AT_AddConstraint */
+			case AT_ReAddDomainConstraint:	/* becomes AT_AddConstraint */
+				if (IsA(cmd->def, Constraint))
+				{
+					Constraint *con = (Constraint *) cmd->def;
+
+					switch (con->contype)
+					{
+						case CONSTR_EXCLUSION:
+						case CONSTR_PRIMARY:
+						case CONSTR_UNIQUE:
+
+							/*
+							 * Cases essentially the same as CREATE INDEX. We
+							 * could reduce the lock strength to ShareLock if
+							 * we can work out how to allow concurrent catalog
+							 * updates. XXX Might be set down to
+							 * ShareRowExclusiveLock but requires further
+							 * analysis.
+							 */
+							cmd_lockmode = AccessExclusiveLock;
+							break;
+						case CONSTR_FOREIGN:
+
+							/*
+							 * We add triggers to both tables when we add a
+							 * Foreign Key, so the lock level must be at least
+							 * as strong as CREATE TRIGGER.
+							 */
+							cmd_lockmode = ShareRowExclusiveLock;
+							break;
+
+						default:
+							cmd_lockmode = AccessExclusiveLock;
+					}
+				}
+				break;
+
+				/*
+				 * These subcommands affect inheritance behaviour. Queries
+				 * started before us will continue to see the old inheritance
+				 * behaviour, while queries started after we commit will see
+				 * new behaviour. No need to prevent reads or writes to the
+				 * subtable while we hook it up though. Changing the TupDesc
+				 * may be a problem, so keep highest lock.
+				 */
+			case AT_AddInherit:
+			case AT_DropInherit:
+				cmd_lockmode = AccessExclusiveLock;
+				break;
+
+				/*
+				 * These subcommands affect implicit row type conversion. They
+				 * have affects similar to CREATE/DROP CAST on queries. don't
+				 * provide for invalidating parse trees as a result of such
+				 * changes, so we keep these at AccessExclusiveLock.
+				 */
+			case AT_AddOf:
+			case AT_DropOf:
+				cmd_lockmode = AccessExclusiveLock;
+				break;
+
+				/*
+				 * Only used by CREATE OR REPLACE VIEW which must conflict
+				 * with an SELECTs currently using the view.
+				 */
+			case AT_ReplaceRelOptions:
+				cmd_lockmode = AccessExclusiveLock;
+				break;
+
+				/*
+				 * These subcommands affect general strategies for performance
+				 * and maintenance, though don't change the semantic results
+				 * from normal data reads and writes. Delaying an ALTER TABLE
+				 * behind currently active writes only delays the point where
+				 * the new strategy begins to take effect, so there is no
+				 * benefit in waiting. In this case the minimum restriction
+				 * applies: we don't currently allow concurrent catalog
+				 * updates.
+				 */
+			case AT_SetStatistics:	/* Uses MVCC in getTableAttrs() */
+			case AT_ClusterOn:	/* Uses MVCC in getIndexes() */
+			case AT_DropCluster:	/* Uses MVCC in getIndexes() */
+			case AT_SetOptions: /* Uses MVCC in getTableAttrs() */
+			case AT_ResetOptions:	/* Uses MVCC in getTableAttrs() */
+				cmd_lockmode = ShareUpdateExclusiveLock;
+				break;
+
+			case AT_SetLogged:
+			case AT_SetUnLogged:
+				cmd_lockmode = AccessExclusiveLock;
+				break;
+
+			case AT_ValidateConstraint: /* Uses MVCC in getConstraints() */
+				cmd_lockmode = ShareUpdateExclusiveLock;
+				break;
+
+				/*
+				 * Rel options are more complex than first appears. Options
+				 * are set here for tables, views and indexes; for historical
+				 * reasons these can all be used with ALTER TABLE, so we can't
+				 * decide between them using the basic grammar.
+				 */
+			case AT_SetRelOptions:	/* Uses MVCC in getIndexes() and
+									 * getTables() */
+			case AT_ResetRelOptions:	/* Uses MVCC in getIndexes() and
+										 * getTables() */
+				cmd_lockmode = AlterTableGetRelOptionsLockLevel((List *) cmd->def);
+				break;
+
+			case AT_AttachPartition:
+				cmd_lockmode = ShareUpdateExclusiveLock;
+				break;
+
+			case AT_DetachPartition:
+				if (((PartitionCmd *) cmd->def)->concurrent)
+					cmd_lockmode = ShareUpdateExclusiveLock;
+				else
+					cmd_lockmode = AccessExclusiveLock;
+				break;
+
+			case AT_DetachPartitionFinalize:
+				cmd_lockmode = ShareUpdateExclusiveLock;
+				break;
+
+			case AT_CheckNotNull:
+
+				/*
+				 * This only examines the table's schema; but lock must be
+				 * strong enough to prevent concurrent DROP NOT NULL.
+				 */
+				cmd_lockmode = AccessShareLock;
+				break;
+
+			default:			/* oops */
+				elog(ERROR, "unrecognized alter table type: %d",
+					 (int) cmd->subtype);
+				break;
+		}
+
+		/*
+		 * Take the greatest lockmode from any subcommand
+		 */
+		if (cmd_lockmode > lockmode)
+			lockmode = cmd_lockmode;
+	}
+
+	return lockmode;
+}
+
+/*
+ * ATController provides top level control over the phases.
+ *
+ * parsetree is passed in to allow it to be passed to event triggers
+ * when requested.
+ */
+static void
+ATController(AlterTableStmt *parsetree,
+			 Relation rel, List *cmds, bool recurse, LOCKMODE lockmode,
+			 AlterTableUtilityContext *context)
+{
+	List	   *wqueue = NIL;
+	ListCell   *lcmd;
+
+	/* Phase 1: preliminary examination of commands, create work queue */
+	foreach(lcmd, cmds)
+	{
+		AlterTableCmd *cmd = (AlterTableCmd *) lfirst(lcmd);
+
+		ATPrepCmd(&wqueue, rel, cmd, recurse, false, lockmode, context);
+	}
+
+	/* Close the relation, but keep lock until commit */
+	relation_close(rel, NoLock);
+
+	/* Phase 2: update system catalogs */
+	ATRewriteCatalogs(&wqueue, lockmode, context);
+
+	/* Phase 3: scan/rewrite tables as needed, and run afterStmts */
+	ATRewriteTables(parsetree, &wqueue, lockmode, context);
+}
+
+/*
+ * ATPrepCmd
+ *
+ * Traffic cop for ALTER TABLE Phase 1 operations, including simple
+ * recursion and permission checks.
+ *
+ * Caller must have acquired appropriate lock type on relation already.
+ * This lock should be held until commit.
+ */
+static void
+ATPrepCmd(List **wqueue, Relation rel, AlterTableCmd *cmd,
+		  bool recurse, bool recursing, LOCKMODE lockmode,
+		  AlterTableUtilityContext *context)
+{
+	AlteredTableInfo *tab;
+	int			pass = AT_PASS_UNSET;
+
+	/* Find or create work queue entry for this table */
+	tab = ATGetQueueEntry(wqueue, rel);
+
+	/*
+	 * Disallow any ALTER TABLE other than ALTER TABLE DETACH FINALIZE on
+	 * partitions that are pending detach.
+	 */
+	if (rel->rd_rel->relispartition &&
+		cmd->subtype != AT_DetachPartitionFinalize &&
+		PartitionHasPendingDetach(RelationGetRelid(rel)))
+		ereport(ERROR,
+				errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+				errmsg("cannot alter partition \"%s\" with an incomplete detach",
+					   RelationGetRelationName(rel)),
+				errhint("Use ALTER TABLE ... DETACH PARTITION ... FINALIZE to complete the pending detach operation."));
+
+	/*
+	 * Copy the original subcommand for each table, so we can scribble on it.
+	 * This avoids conflicts when different child tables need to make
+	 * different parse transformations (for example, the same column may have
+	 * different column numbers in different children).
+	 */
+	cmd = copyObject(cmd);
+
+	/*
+	 * Do permissions and relkind checking, recursion to child tables if
+	 * needed, and any additional phase-1 processing needed.  (But beware of
+	 * adding any processing that looks at table details that another
+	 * subcommand could change.  In some cases we reject multiple subcommands
+	 * that could try to change the same state in contrary ways.)
+	 */
+	switch (cmd->subtype)
+	{
+		case AT_AddColumn:		/* ADD COLUMN */
+			ATSimplePermissions(cmd->subtype, rel,
+								ATT_TABLE | ATT_COMPOSITE_TYPE | ATT_FOREIGN_TABLE);
+			ATPrepAddColumn(wqueue, rel, recurse, recursing, false, cmd,
+							lockmode, context);
+			/* Recursion occurs during execution phase */
+			pass = AT_PASS_ADD_COL;
+			break;
+		case AT_AddColumnToView:	/* add column via CREATE OR REPLACE VIEW */
+			ATSimplePermissions(cmd->subtype, rel, ATT_VIEW);
+			ATPrepAddColumn(wqueue, rel, recurse, recursing, true, cmd,
+							lockmode, context);
+			/* Recursion occurs during execution phase */
+			pass = AT_PASS_ADD_COL;
+			break;
+		case AT_ColumnDefault:	/* ALTER COLUMN DEFAULT */
+
+			/*
+			 * We allow defaults on views so that INSERT into a view can have
+			 * default-ish behavior.  This works because the rewriter
+			 * substitutes default values into INSERTs before it expands
+			 * rules.
+			 */
+			ATSimplePermissions(cmd->subtype, rel, ATT_TABLE | ATT_VIEW | ATT_FOREIGN_TABLE);
+			ATSimpleRecursion(wqueue, rel, cmd, recurse, lockmode, context);
+			/* No command-specific prep needed */
+			pass = cmd->def ? AT_PASS_ADD_OTHERCONSTR : AT_PASS_DROP;
+			break;
+		case AT_CookedColumnDefault:	/* add a pre-cooked default */
+			/* This is currently used only in CREATE TABLE */
+			/* (so the permission check really isn't necessary) */
+			ATSimplePermissions(cmd->subtype, rel, ATT_TABLE | ATT_FOREIGN_TABLE);
+			/* This command never recurses */
+			pass = AT_PASS_ADD_OTHERCONSTR;
+			break;
+		case AT_AddIdentity:
+			ATSimplePermissions(cmd->subtype, rel, ATT_TABLE | ATT_VIEW | ATT_FOREIGN_TABLE);
+			/* This command never recurses */
+			pass = AT_PASS_ADD_OTHERCONSTR;
+			break;
+		case AT_SetIdentity:
+			ATSimplePermissions(cmd->subtype, rel, ATT_TABLE | ATT_VIEW | ATT_FOREIGN_TABLE);
+			/* This command never recurses */
+			/* This should run after AddIdentity, so do it in MISC pass */
+			pass = AT_PASS_MISC;
+			break;
+		case AT_DropIdentity:
+			ATSimplePermissions(cmd->subtype, rel, ATT_TABLE | ATT_VIEW | ATT_FOREIGN_TABLE);
+			/* This command never recurses */
+			pass = AT_PASS_DROP;
+			break;
+		case AT_DropNotNull:	/* ALTER COLUMN DROP NOT NULL */
+			ATSimplePermissions(cmd->subtype, rel, ATT_TABLE | ATT_FOREIGN_TABLE);
+			ATPrepDropNotNull(rel, recurse, recursing);
+			ATSimpleRecursion(wqueue, rel, cmd, recurse, lockmode, context);
+			pass = AT_PASS_DROP;
+			break;
+		case AT_SetNotNull:		/* ALTER COLUMN SET NOT NULL */
+			ATSimplePermissions(cmd->subtype, rel, ATT_TABLE | ATT_FOREIGN_TABLE);
+			/* Need command-specific recursion decision */
+			ATPrepSetNotNull(wqueue, rel, cmd, recurse, recursing,
+							 lockmode, context);
+			pass = AT_PASS_COL_ATTRS;
+			break;
+		case AT_CheckNotNull:	/* check column is already marked NOT NULL */
+			ATSimplePermissions(cmd->subtype, rel, ATT_TABLE | ATT_FOREIGN_TABLE);
+			ATSimpleRecursion(wqueue, rel, cmd, recurse, lockmode, context);
+			/* No command-specific prep needed */
+			pass = AT_PASS_COL_ATTRS;
+			break;
+		case AT_DropExpression: /* ALTER COLUMN DROP EXPRESSION */
+			ATSimplePermissions(cmd->subtype, rel, ATT_TABLE | ATT_FOREIGN_TABLE);
+			ATSimpleRecursion(wqueue, rel, cmd, recurse, lockmode, context);
+			ATPrepDropExpression(rel, cmd, recurse, recursing, lockmode);
+			pass = AT_PASS_DROP;
+			break;
+		case AT_SetStatistics:	/* ALTER COLUMN SET STATISTICS */
+			ATSimplePermissions(cmd->subtype, rel, ATT_TABLE | ATT_MATVIEW | ATT_INDEX | ATT_PARTITIONED_INDEX | ATT_FOREIGN_TABLE);
+			ATSimpleRecursion(wqueue, rel, cmd, recurse, lockmode, context);
+			/* No command-specific prep needed */
+			pass = AT_PASS_MISC;
+			break;
+		case AT_SetOptions:		/* ALTER COLUMN SET ( options ) */
+		case AT_ResetOptions:	/* ALTER COLUMN RESET ( options ) */
+			ATSimplePermissions(cmd->subtype, rel, ATT_TABLE | ATT_MATVIEW | ATT_FOREIGN_TABLE);
+			/* This command never recurses */
+			pass = AT_PASS_MISC;
+			break;
+		case AT_SetStorage:		/* ALTER COLUMN SET STORAGE */
+			ATSimplePermissions(cmd->subtype, rel, ATT_TABLE | ATT_MATVIEW | ATT_FOREIGN_TABLE);
+			ATSimpleRecursion(wqueue, rel, cmd, recurse, lockmode, context);
+			/* No command-specific prep needed */
+			pass = AT_PASS_MISC;
+			break;
+		case AT_SetCompression: /* ALTER COLUMN SET COMPRESSION */
+			ATSimplePermissions(cmd->subtype, rel, ATT_TABLE | ATT_MATVIEW);
+			/* This command never recurses */
+			/* No command-specific prep needed */
+			pass = AT_PASS_MISC;
+			break;
+		case AT_DropColumn:		/* DROP COLUMN */
+			ATSimplePermissions(cmd->subtype, rel,
+								ATT_TABLE | ATT_COMPOSITE_TYPE | ATT_FOREIGN_TABLE);
+			ATPrepDropColumn(wqueue, rel, recurse, recursing, cmd,
+							 lockmode, context);
+			/* Recursion occurs during execution phase */
+			pass = AT_PASS_DROP;
+			break;
+		case AT_AddIndex:		/* ADD INDEX */
+			ATSimplePermissions(cmd->subtype, rel, ATT_TABLE);
+			/* This command never recurses */
+			/* No command-specific prep needed */
+			pass = AT_PASS_ADD_INDEX;
+			break;
+		case AT_AddConstraint:	/* ADD CONSTRAINT */
+			ATSimplePermissions(cmd->subtype, rel, ATT_TABLE | ATT_FOREIGN_TABLE);
+			/* Recursion occurs during execution phase */
+			/* No command-specific prep needed except saving recurse flag */
+			if (recurse)
+				cmd->subtype = AT_AddConstraintRecurse;
+			pass = AT_PASS_ADD_CONSTR;
+			break;
+		case AT_AddIndexConstraint: /* ADD CONSTRAINT USING INDEX */
+			ATSimplePermissions(cmd->subtype, rel, ATT_TABLE);
+			/* This command never recurses */
+			/* No command-specific prep needed */
+			pass = AT_PASS_ADD_INDEXCONSTR;
+			break;
+		case AT_DropConstraint: /* DROP CONSTRAINT */
+			ATSimplePermissions(cmd->subtype, rel, ATT_TABLE | ATT_FOREIGN_TABLE);
+			ATCheckPartitionsNotInUse(rel, lockmode);
+			/* Other recursion occurs during execution phase */
+			/* No command-specific prep needed except saving recurse flag */
+			if (recurse)
+				cmd->subtype = AT_DropConstraintRecurse;
+			pass = AT_PASS_DROP;
+			break;
+		case AT_AlterColumnType:	/* ALTER COLUMN TYPE */
+			ATSimplePermissions(cmd->subtype, rel,
+								ATT_TABLE | ATT_COMPOSITE_TYPE | ATT_FOREIGN_TABLE);
+			/* See comments for ATPrepAlterColumnType */
+			cmd = ATParseTransformCmd(wqueue, tab, rel, cmd, recurse, lockmode,
+									  AT_PASS_UNSET, context);
+			Assert(cmd != NULL);
+			/* Performs own recursion */
+			ATPrepAlterColumnType(wqueue, tab, rel, recurse, recursing, cmd,
+								  lockmode, context);
+			pass = AT_PASS_ALTER_TYPE;
+			break;
+		case AT_AlterColumnGenericOptions:
+			ATSimplePermissions(cmd->subtype, rel, ATT_FOREIGN_TABLE);
+			/* This command never recurses */
+			/* No command-specific prep needed */
+			pass = AT_PASS_MISC;
+			break;
+		case AT_ChangeOwner:	/* ALTER OWNER */
+			/* This command never recurses */
+			/* No command-specific prep needed */
+			pass = AT_PASS_MISC;
+			break;
+		case AT_ClusterOn:		/* CLUSTER ON */
+		case AT_DropCluster:	/* SET WITHOUT CLUSTER */
+			ATSimplePermissions(cmd->subtype, rel, ATT_TABLE | ATT_MATVIEW);
+			/* These commands never recurse */
+			/* No command-specific prep needed */
+			pass = AT_PASS_MISC;
+			break;
+		case AT_SetLogged:		/* SET LOGGED */
+			ATSimplePermissions(cmd->subtype, rel, ATT_TABLE | ATT_SEQUENCE);
+			if (tab->chgPersistence)
+				ereport(ERROR,
+						(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+						 errmsg("cannot change persistence setting twice")));
+			tab->chgPersistence = ATPrepChangePersistence(rel, true);
+			/* force rewrite if necessary; see comment in ATRewriteTables */
+			if (tab->chgPersistence)
+			{
+				tab->rewrite |= AT_REWRITE_ALTER_PERSISTENCE;
+				tab->newrelpersistence = RELPERSISTENCE_PERMANENT;
+			}
+			pass = AT_PASS_MISC;
+			break;
+		case AT_SetUnLogged:	/* SET UNLOGGED */
+			ATSimplePermissions(cmd->subtype, rel, ATT_TABLE | ATT_SEQUENCE);
+			if (tab->chgPersistence)
+				ereport(ERROR,
+						(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+						 errmsg("cannot change persistence setting twice")));
+			tab->chgPersistence = ATPrepChangePersistence(rel, false);
+			/* force rewrite if necessary; see comment in ATRewriteTables */
+			if (tab->chgPersistence)
+			{
+				tab->rewrite |= AT_REWRITE_ALTER_PERSISTENCE;
+				tab->newrelpersistence = RELPERSISTENCE_UNLOGGED;
+			}
+			pass = AT_PASS_MISC;
+			break;
+		case AT_DropOids:		/* SET WITHOUT OIDS */
+			ATSimplePermissions(cmd->subtype, rel, ATT_TABLE | ATT_FOREIGN_TABLE);
+			pass = AT_PASS_DROP;
+			break;
+		case AT_SetAccessMethod:	/* SET ACCESS METHOD */
+			ATSimplePermissions(cmd->subtype, rel, ATT_TABLE | ATT_MATVIEW);
+
+			/* partitioned tables don't have an access method */
+			if (rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
+				ereport(ERROR,
+						(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+						 errmsg("cannot change access method of a partitioned table")));
+
+			/* check if another access method change was already requested */
+			if (OidIsValid(tab->newAccessMethod))
+				ereport(ERROR,
+						(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+						 errmsg("cannot have multiple SET ACCESS METHOD subcommands")));
+
+			ATPrepSetAccessMethod(tab, rel, cmd->name);
+			pass = AT_PASS_MISC;	/* does not matter; no work in Phase 2 */
+			break;
+		case AT_SetTableSpace:	/* SET TABLESPACE */
+			ATSimplePermissions(cmd->subtype, rel, ATT_TABLE | ATT_MATVIEW | ATT_INDEX |
+								ATT_PARTITIONED_INDEX);
+			/* This command never recurses */
+			ATPrepSetTableSpace(tab, rel, cmd->name, lockmode);
+			pass = AT_PASS_MISC;	/* doesn't actually matter */
+			break;
+		case AT_SetRelOptions:	/* SET (...) */
+		case AT_ResetRelOptions:	/* RESET (...) */
+		case AT_ReplaceRelOptions:	/* reset them all, then set just these */
+			ATSimplePermissions(cmd->subtype, rel, ATT_TABLE | ATT_VIEW | ATT_MATVIEW | ATT_INDEX);
+			/* This command never recurses */
+			/* No command-specific prep needed */
+			pass = AT_PASS_MISC;
+			break;
+		case AT_AddInherit:		/* INHERIT */
+			ATSimplePermissions(cmd->subtype, rel, ATT_TABLE | ATT_FOREIGN_TABLE);
+			/* This command never recurses */
+			ATPrepAddInherit(rel);
+			pass = AT_PASS_MISC;
+			break;
+		case AT_DropInherit:	/* NO INHERIT */
+			ATSimplePermissions(cmd->subtype, rel, ATT_TABLE | ATT_FOREIGN_TABLE);
+			/* This command never recurses */
+			/* No command-specific prep needed */
+			pass = AT_PASS_MISC;
+			break;
+		case AT_AlterConstraint:	/* ALTER CONSTRAINT */
+			ATSimplePermissions(cmd->subtype, rel, ATT_TABLE);
+			/* Recursion occurs during execution phase */
+			pass = AT_PASS_MISC;
+			break;
+		case AT_ValidateConstraint: /* VALIDATE CONSTRAINT */
+			ATSimplePermissions(cmd->subtype, rel, ATT_TABLE | ATT_FOREIGN_TABLE);
+			/* Recursion occurs during execution phase */
+			/* No command-specific prep needed except saving recurse flag */
+			if (recurse)
+				cmd->subtype = AT_ValidateConstraintRecurse;
+			pass = AT_PASS_MISC;
+			break;
+		case AT_ReplicaIdentity:	/* REPLICA IDENTITY ... */
+			ATSimplePermissions(cmd->subtype, rel, ATT_TABLE | ATT_MATVIEW);
+			pass = AT_PASS_MISC;
+			/* This command never recurses */
+			/* No command-specific prep needed */
+			break;
+		case AT_EnableTrig:		/* ENABLE TRIGGER variants */
+		case AT_EnableAlwaysTrig:
+		case AT_EnableReplicaTrig:
+		case AT_EnableTrigAll:
+		case AT_EnableTrigUser:
+		case AT_DisableTrig:	/* DISABLE TRIGGER variants */
+		case AT_DisableTrigAll:
+		case AT_DisableTrigUser:
+			ATSimplePermissions(cmd->subtype, rel, ATT_TABLE | ATT_FOREIGN_TABLE);
+			/* Set up recursion for phase 2; no other prep needed */
+			if (recurse)
+				cmd->recurse = true;
+			pass = AT_PASS_MISC;
+			break;
+		case AT_EnableRule:		/* ENABLE/DISABLE RULE variants */
+		case AT_EnableAlwaysRule:
+		case AT_EnableReplicaRule:
+		case AT_DisableRule:
+		case AT_AddOf:			/* OF */
+		case AT_DropOf:			/* NOT OF */
+		case AT_EnableRowSecurity:
+		case AT_DisableRowSecurity:
+		case AT_ForceRowSecurity:
+		case AT_NoForceRowSecurity:
+			ATSimplePermissions(cmd->subtype, rel, ATT_TABLE);
+			/* These commands never recurse */
+			/* No command-specific prep needed */
+			pass = AT_PASS_MISC;
+			break;
+		case AT_GenericOptions:
+			ATSimplePermissions(cmd->subtype, rel, ATT_FOREIGN_TABLE);
+			/* No command-specific prep needed */
+			pass = AT_PASS_MISC;
+			break;
+		case AT_AttachPartition:
+			ATSimplePermissions(cmd->subtype, rel, ATT_TABLE | ATT_PARTITIONED_INDEX);
+			/* No command-specific prep needed */
+			pass = AT_PASS_MISC;
+			break;
+		case AT_DetachPartition:
+			ATSimplePermissions(cmd->subtype, rel, ATT_TABLE);
+			/* No command-specific prep needed */
+			pass = AT_PASS_MISC;
+			break;
+		case AT_DetachPartitionFinalize:
+			ATSimplePermissions(cmd->subtype, rel, ATT_TABLE);
+			/* No command-specific prep needed */
+			pass = AT_PASS_MISC;
+			break;
+		default:				/* oops */
+			elog(ERROR, "unrecognized alter table type: %d",
+				 (int) cmd->subtype);
+			pass = AT_PASS_UNSET;	/* keep compiler quiet */
+			break;
+	}
+	Assert(pass > AT_PASS_UNSET);
+
+	/* Add the subcommand to the appropriate list for phase 2 */
+	tab->subcmds[pass] = lappend(tab->subcmds[pass], cmd);
+}
+
+/*
+ * ATRewriteCatalogs
+ *
+ * Traffic cop for ALTER TABLE Phase 2 operations.  Subcommands are
+ * dispatched in a "safe" execution order (designed to avoid unnecessary
+ * conflicts).
+ */
+static void
+ATRewriteCatalogs(List **wqueue, LOCKMODE lockmode,
+				  AlterTableUtilityContext *context)
+{
+	int			pass;
+	ListCell   *ltab;
+
+	/*
+	 * We process all the tables "in parallel", one pass at a time.  This is
+	 * needed because we may have to propagate work from one table to another
+	 * (specifically, ALTER TYPE on a foreign key's PK has to dispatch the
+	 * re-adding of the foreign key constraint to the other table).  Work can
+	 * only be propagated into later passes, however.
+	 */
+	for (pass = 0; pass < AT_NUM_PASSES; pass++)
+	{
+		/* Go through each table that needs to be processed */
+		foreach(ltab, *wqueue)
+		{
+			AlteredTableInfo *tab = (AlteredTableInfo *) lfirst(ltab);
+			List	   *subcmds = tab->subcmds[pass];
+			ListCell   *lcmd;
+
+			if (subcmds == NIL)
+				continue;
+
+			/*
+			 * Open the relation and store it in tab.  This allows subroutines
+			 * close and reopen, if necessary.  Appropriate lock was obtained
+			 * by phase 1, needn't get it again.
+			 */
+			tab->rel = relation_open(tab->relid, NoLock);
+
+			foreach(lcmd, subcmds)
+				ATExecCmd(wqueue, tab,
+						  lfirst_node(AlterTableCmd, lcmd),
+						  lockmode, pass, context);
+
+			/*
+			 * After the ALTER TYPE pass, do cleanup work (this is not done in
+			 * ATExecAlterColumnType since it should be done only once if
+			 * multiple columns of a table are altered).
+			 */
+			if (pass == AT_PASS_ALTER_TYPE)
+				ATPostAlterTypeCleanup(wqueue, tab, lockmode);
+
+			if (tab->rel)
+			{
+				relation_close(tab->rel, NoLock);
+				tab->rel = NULL;
+			}
+		}
+	}
+
+	/* Check to see if a toast table must be added. */
+	foreach(ltab, *wqueue)
+	{
+		AlteredTableInfo *tab = (AlteredTableInfo *) lfirst(ltab);
+
+		/*
+		 * If the table is source table of ATTACH PARTITION command, we did
+		 * not modify anything about it that will change its toasting
+		 * requirement, so no need to check.
+		 */
+		if (((tab->relkind == RELKIND_RELATION ||
+			  tab->relkind == RELKIND_PARTITIONED_TABLE) &&
+			 tab->partition_constraint == NULL) ||
+			tab->relkind == RELKIND_MATVIEW)
+			AlterTableCreateToastTable(tab->relid, (Datum) 0, lockmode);
+	}
+}
+
+/*
+ * ATExecCmd: dispatch a subcommand to appropriate execution routine
+ */
+static void
+ATExecCmd(List **wqueue, AlteredTableInfo *tab,
+		  AlterTableCmd *cmd, LOCKMODE lockmode, int cur_pass,
+		  AlterTableUtilityContext *context)
+{
+	ObjectAddress address = InvalidObjectAddress;
+	Relation	rel = tab->rel;
+
+	switch (cmd->subtype)
+	{
+		case AT_AddColumn:		/* ADD COLUMN */
+		case AT_AddColumnToView:	/* add column via CREATE OR REPLACE VIEW */
+			address = ATExecAddColumn(wqueue, tab, rel, &cmd,
+									  false, false,
+									  lockmode, cur_pass, context);
+			break;
+		case AT_AddColumnRecurse:
+			address = ATExecAddColumn(wqueue, tab, rel, &cmd,
+									  true, false,
+									  lockmode, cur_pass, context);
+			break;
+		case AT_ColumnDefault:	/* ALTER COLUMN DEFAULT */
+			address = ATExecColumnDefault(rel, cmd->name, cmd->def, lockmode);
+			break;
+		case AT_CookedColumnDefault:	/* add a pre-cooked default */
+			address = ATExecCookedColumnDefault(rel, cmd->num, cmd->def);
+			break;
+		case AT_AddIdentity:
+			cmd = ATParseTransformCmd(wqueue, tab, rel, cmd, false, lockmode,
+									  cur_pass, context);
+			Assert(cmd != NULL);
+			address = ATExecAddIdentity(rel, cmd->name, cmd->def, lockmode);
+			break;
+		case AT_SetIdentity:
+			cmd = ATParseTransformCmd(wqueue, tab, rel, cmd, false, lockmode,
+									  cur_pass, context);
+			Assert(cmd != NULL);
+			address = ATExecSetIdentity(rel, cmd->name, cmd->def, lockmode);
+			break;
+		case AT_DropIdentity:
+			address = ATExecDropIdentity(rel, cmd->name, cmd->missing_ok, lockmode);
+			break;
+		case AT_DropNotNull:	/* ALTER COLUMN DROP NOT NULL */
+			address = ATExecDropNotNull(rel, cmd->name, lockmode);
+			break;
+		case AT_SetNotNull:		/* ALTER COLUMN SET NOT NULL */
+			address = ATExecSetNotNull(tab, rel, cmd->name, lockmode);
+			break;
+		case AT_CheckNotNull:	/* check column is already marked NOT NULL */
+			ATExecCheckNotNull(tab, rel, cmd->name, lockmode);
+			break;
+		case AT_DropExpression:
+			address = ATExecDropExpression(rel, cmd->name, cmd->missing_ok, lockmode);
+			break;
+		case AT_SetStatistics:	/* ALTER COLUMN SET STATISTICS */
+			address = ATExecSetStatistics(rel, cmd->name, cmd->num, cmd->def, lockmode);
+			break;
+		case AT_SetOptions:		/* ALTER COLUMN SET ( options ) */
+			address = ATExecSetOptions(rel, cmd->name, cmd->def, false, lockmode);
+			break;
+		case AT_ResetOptions:	/* ALTER COLUMN RESET ( options ) */
+			address = ATExecSetOptions(rel, cmd->name, cmd->def, true, lockmode);
+			break;
+		case AT_SetStorage:		/* ALTER COLUMN SET STORAGE */
+			address = ATExecSetStorage(rel, cmd->name, cmd->def, lockmode);
+			break;
+		case AT_SetCompression:
+			address = ATExecSetCompression(tab, rel, cmd->name, cmd->def,
+										   lockmode);
+			break;
+		case AT_DropColumn:		/* DROP COLUMN */
+			address = ATExecDropColumn(wqueue, rel, cmd->name,
+									   cmd->behavior, false, false,
+									   cmd->missing_ok, lockmode,
+									   NULL);
+			break;
+		case AT_DropColumnRecurse:	/* DROP COLUMN with recursion */
+			address = ATExecDropColumn(wqueue, rel, cmd->name,
+									   cmd->behavior, true, false,
+									   cmd->missing_ok, lockmode,
+									   NULL);
+			break;
+		case AT_AddIndex:		/* ADD INDEX */
+			address = ATExecAddIndex(tab, rel, (IndexStmt *) cmd->def, false,
+									 lockmode);
+			break;
+		case AT_ReAddIndex:		/* ADD INDEX */
+			address = ATExecAddIndex(tab, rel, (IndexStmt *) cmd->def, true,
+									 lockmode);
+			break;
+		case AT_ReAddStatistics:	/* ADD STATISTICS */
+			address = ATExecAddStatistics(tab, rel, (CreateStatsStmt *) cmd->def,
+										  true, lockmode);
+			break;
+		case AT_AddConstraint:	/* ADD CONSTRAINT */
+			/* Transform the command only during initial examination */
+			if (cur_pass == AT_PASS_ADD_CONSTR)
+				cmd = ATParseTransformCmd(wqueue, tab, rel, cmd,
+										  false, lockmode,
+										  cur_pass, context);
+			/* Depending on constraint type, might be no more work to do now */
+			if (cmd != NULL)
+				address =
+					ATExecAddConstraint(wqueue, tab, rel,
+										(Constraint *) cmd->def,
+										false, false, lockmode);
+			break;
+		case AT_AddConstraintRecurse:	/* ADD CONSTRAINT with recursion */
+			/* Transform the command only during initial examination */
+			if (cur_pass == AT_PASS_ADD_CONSTR)
+				cmd = ATParseTransformCmd(wqueue, tab, rel, cmd,
+										  true, lockmode,
+										  cur_pass, context);
+			/* Depending on constraint type, might be no more work to do now */
+			if (cmd != NULL)
+				address =
+					ATExecAddConstraint(wqueue, tab, rel,
+										(Constraint *) cmd->def,
+										true, false, lockmode);
+			break;
+		case AT_ReAddConstraint:	/* Re-add pre-existing check constraint */
+			address =
+				ATExecAddConstraint(wqueue, tab, rel, (Constraint *) cmd->def,
+									true, true, lockmode);
+			break;
+		case AT_ReAddDomainConstraint:	/* Re-add pre-existing domain check
+										 * constraint */
+			address =
+				AlterDomainAddConstraint(((AlterDomainStmt *) cmd->def)->typeName,
+										 ((AlterDomainStmt *) cmd->def)->def,
+										 NULL);
+			break;
+		case AT_ReAddComment:	/* Re-add existing comment */
+			address = CommentObject((CommentStmt *) cmd->def);
+			break;
+		case AT_AddIndexConstraint: /* ADD CONSTRAINT USING INDEX */
+			address = ATExecAddIndexConstraint(tab, rel, (IndexStmt *) cmd->def,
+											   lockmode);
+			break;
+		case AT_AlterConstraint:	/* ALTER CONSTRAINT */
+			address = ATExecAlterConstraint(rel, cmd, false, false, lockmode);
+			break;
+		case AT_ValidateConstraint: /* VALIDATE CONSTRAINT */
+			address = ATExecValidateConstraint(wqueue, rel, cmd->name, false,
+											   false, lockmode);
+			break;
+		case AT_ValidateConstraintRecurse:	/* VALIDATE CONSTRAINT with
+											 * recursion */
+			address = ATExecValidateConstraint(wqueue, rel, cmd->name, true,
+											   false, lockmode);
+			break;
+		case AT_DropConstraint: /* DROP CONSTRAINT */
+			ATExecDropConstraint(rel, cmd->name, cmd->behavior,
+								 false, false,
+								 cmd->missing_ok, lockmode);
+			break;
+		case AT_DropConstraintRecurse:	/* DROP CONSTRAINT with recursion */
+			ATExecDropConstraint(rel, cmd->name, cmd->behavior,
+								 true, false,
+								 cmd->missing_ok, lockmode);
+			break;
+		case AT_AlterColumnType:	/* ALTER COLUMN TYPE */
+			/* parse transformation was done earlier */
+			address = ATExecAlterColumnType(tab, rel, cmd, lockmode);
+			break;
+		case AT_AlterColumnGenericOptions:	/* ALTER COLUMN OPTIONS */
+			address =
+				ATExecAlterColumnGenericOptions(rel, cmd->name,
+												(List *) cmd->def, lockmode);
+			break;
+		case AT_ChangeOwner:	/* ALTER OWNER */
+			ATExecChangeOwner(RelationGetRelid(rel),
+							  get_rolespec_oid(cmd->newowner, false),
+							  false, lockmode);
+			break;
+		case AT_ClusterOn:		/* CLUSTER ON */
+			address = ATExecClusterOn(rel, cmd->name, lockmode);
+			break;
+		case AT_DropCluster:	/* SET WITHOUT CLUSTER */
+			ATExecDropCluster(rel, lockmode);
+			break;
+		case AT_SetLogged:		/* SET LOGGED */
+		case AT_SetUnLogged:	/* SET UNLOGGED */
+			break;
+		case AT_DropOids:		/* SET WITHOUT OIDS */
+			/* nothing to do here, oid columns don't exist anymore */
+			break;
+		case AT_SetAccessMethod:	/* SET ACCESS METHOD */
+			/* handled specially in Phase 3 */
+			break;
+		case AT_SetTableSpace:	/* SET TABLESPACE */
+
+			/*
+			 * Only do this for partitioned tables and indexes, for which this
+			 * is just a catalog change.  Other relation types which have
+			 * storage are handled by Phase 3.
+			 */
+			if (rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE ||
+				rel->rd_rel->relkind == RELKIND_PARTITIONED_INDEX)
+				ATExecSetTableSpaceNoStorage(rel, tab->newTableSpace);
+
+			break;
+		case AT_SetRelOptions:	/* SET (...) */
+		case AT_ResetRelOptions:	/* RESET (...) */
+		case AT_ReplaceRelOptions:	/* replace entire option list */
+			ATExecSetRelOptions(rel, (List *) cmd->def, cmd->subtype, lockmode);
+			break;
+		case AT_EnableTrig:		/* ENABLE TRIGGER name */
+			ATExecEnableDisableTrigger(rel, cmd->name,
+									   TRIGGER_FIRES_ON_ORIGIN, false,
+									   cmd->recurse,
+									   lockmode);
+			break;
+		case AT_EnableAlwaysTrig:	/* ENABLE ALWAYS TRIGGER name */
+			ATExecEnableDisableTrigger(rel, cmd->name,
+									   TRIGGER_FIRES_ALWAYS, false,
+									   cmd->recurse,
+									   lockmode);
+			break;
+		case AT_EnableReplicaTrig:	/* ENABLE REPLICA TRIGGER name */
+			ATExecEnableDisableTrigger(rel, cmd->name,
+									   TRIGGER_FIRES_ON_REPLICA, false,
+									   cmd->recurse,
+									   lockmode);
+			break;
+		case AT_DisableTrig:	/* DISABLE TRIGGER name */
+			ATExecEnableDisableTrigger(rel, cmd->name,
+									   TRIGGER_DISABLED, false,
+									   cmd->recurse,
+									   lockmode);
+			break;
+		case AT_EnableTrigAll:	/* ENABLE TRIGGER ALL */
+			ATExecEnableDisableTrigger(rel, NULL,
+									   TRIGGER_FIRES_ON_ORIGIN, false,
+									   cmd->recurse,
+									   lockmode);
+			break;
+		case AT_DisableTrigAll: /* DISABLE TRIGGER ALL */
+			ATExecEnableDisableTrigger(rel, NULL,
+									   TRIGGER_DISABLED, false,
+									   cmd->recurse,
+									   lockmode);
+			break;
+		case AT_EnableTrigUser: /* ENABLE TRIGGER USER */
+			ATExecEnableDisableTrigger(rel, NULL,
+									   TRIGGER_FIRES_ON_ORIGIN, true,
+									   cmd->recurse,
+									   lockmode);
+			break;
+		case AT_DisableTrigUser:	/* DISABLE TRIGGER USER */
+			ATExecEnableDisableTrigger(rel, NULL,
+									   TRIGGER_DISABLED, true,
+									   cmd->recurse,
+									   lockmode);
+			break;
+
+		case AT_EnableRule:		/* ENABLE RULE name */
+			ATExecEnableDisableRule(rel, cmd->name,
+									RULE_FIRES_ON_ORIGIN, lockmode);
+			break;
+		case AT_EnableAlwaysRule:	/* ENABLE ALWAYS RULE name */
+			ATExecEnableDisableRule(rel, cmd->name,
+									RULE_FIRES_ALWAYS, lockmode);
+			break;
+		case AT_EnableReplicaRule:	/* ENABLE REPLICA RULE name */
+			ATExecEnableDisableRule(rel, cmd->name,
+									RULE_FIRES_ON_REPLICA, lockmode);
+			break;
+		case AT_DisableRule:	/* DISABLE RULE name */
+			ATExecEnableDisableRule(rel, cmd->name,
+									RULE_DISABLED, lockmode);
+			break;
+
+		case AT_AddInherit:
+			address = ATExecAddInherit(rel, (RangeVar *) cmd->def, lockmode);
+			break;
+		case AT_DropInherit:
+			address = ATExecDropInherit(rel, (RangeVar *) cmd->def, lockmode);
+			break;
+		case AT_AddOf:
+			address = ATExecAddOf(rel, (TypeName *) cmd->def, lockmode);
+			break;
+		case AT_DropOf:
+			ATExecDropOf(rel, lockmode);
+			break;
+		case AT_ReplicaIdentity:
+			ATExecReplicaIdentity(rel, (ReplicaIdentityStmt *) cmd->def, lockmode);
+			break;
+		case AT_EnableRowSecurity:
+			ATExecSetRowSecurity(rel, true);
+			break;
+		case AT_DisableRowSecurity:
+			ATExecSetRowSecurity(rel, false);
+			break;
+		case AT_ForceRowSecurity:
+			ATExecForceNoForceRowSecurity(rel, true);
+			break;
+		case AT_NoForceRowSecurity:
+			ATExecForceNoForceRowSecurity(rel, false);
+			break;
+		case AT_GenericOptions:
+			ATExecGenericOptions(rel, (List *) cmd->def);
+			break;
+		case AT_AttachPartition:
+			cmd = ATParseTransformCmd(wqueue, tab, rel, cmd, false, lockmode,
+									  cur_pass, context);
+			Assert(cmd != NULL);
+			if (rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
+				ATExecAttachPartition(wqueue, rel, (PartitionCmd *) cmd->def,
+									  context);
+			else
+				ATExecAttachPartitionIdx(wqueue, rel,
+										 ((PartitionCmd *) cmd->def)->name);
+			break;
+		case AT_DetachPartition:
+			cmd = ATParseTransformCmd(wqueue, tab, rel, cmd, false, lockmode,
+									  cur_pass, context);
+			Assert(cmd != NULL);
+			/* ATPrepCmd ensures it must be a table */
+			Assert(rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE);
+			ATExecDetachPartition(wqueue, tab, rel,
+								  ((PartitionCmd *) cmd->def)->name,
+								  ((PartitionCmd *) cmd->def)->concurrent);
+			break;
+		case AT_DetachPartitionFinalize:
+			ATExecDetachPartitionFinalize(rel, ((PartitionCmd *) cmd->def)->name);
+			break;
+		default:				/* oops */
+			elog(ERROR, "unrecognized alter table type: %d",
+				 (int) cmd->subtype);
+			break;
+	}
+
+	/*
+	 * Report the subcommand to interested event triggers.
+	 */
+	if (cmd)
+		EventTriggerCollectAlterTableSubcmd((Node *) cmd, address);
+
+	/*
+	 * Bump the command counter to ensure the next subcommand in the sequence
+	 * can see the changes so far
+	 */
+	CommandCounterIncrement();
+}
+
+/*
+ * ATParseTransformCmd: perform parse transformation for one subcommand
+ *
+ * Returns the transformed subcommand tree, if there is one, else NULL.
+ *
+ * The parser may hand back additional AlterTableCmd(s) and/or other
+ * utility statements, either before or after the original subcommand.
+ * Other AlterTableCmds are scheduled into the appropriate slot of the
+ * AlteredTableInfo (they had better be for later passes than the current one).
+ * Utility statements that are supposed to happen before the AlterTableCmd
+ * are executed immediately.  Those that are supposed to happen afterwards
+ * are added to the tab->afterStmts list to be done at the very end.
+ */
+static AlterTableCmd *
+ATParseTransformCmd(List **wqueue, AlteredTableInfo *tab, Relation rel,
+					AlterTableCmd *cmd, bool recurse, LOCKMODE lockmode,
+					int cur_pass, AlterTableUtilityContext *context)
+{
+	AlterTableCmd *newcmd = NULL;
+	AlterTableStmt *atstmt = makeNode(AlterTableStmt);
+	List	   *beforeStmts;
+	List	   *afterStmts;
+	ListCell   *lc;
+
+	/* Gin up an AlterTableStmt with just this subcommand and this table */
+	atstmt->relation =
+		makeRangeVar(get_namespace_name(RelationGetNamespace(rel)),
+					 pstrdup(RelationGetRelationName(rel)),
+					 -1);
+	atstmt->relation->inh = recurse;
+	atstmt->cmds = list_make1(cmd);
+	atstmt->objtype = OBJECT_TABLE; /* needn't be picky here */
+	atstmt->missing_ok = false;
+
+	/* Transform the AlterTableStmt */
+	atstmt = transformAlterTableStmt(RelationGetRelid(rel),
+									 atstmt,
+									 context->queryString,
+									 &beforeStmts,
+									 &afterStmts);
+
+	/* Execute any statements that should happen before these subcommand(s) */
+	foreach(lc, beforeStmts)
+	{
+		Node	   *stmt = (Node *) lfirst(lc);
+
+		ProcessUtilityForAlterTable(stmt, context);
+		CommandCounterIncrement();
+	}
+
+	/* Examine the transformed subcommands and schedule them appropriately */
+	foreach(lc, atstmt->cmds)
+	{
+		AlterTableCmd *cmd2 = lfirst_node(AlterTableCmd, lc);
+		int			pass;
+
+		/*
+		 * This switch need only cover the subcommand types that can be added
+		 * by parse_utilcmd.c; otherwise, we'll use the default strategy of
+		 * executing the subcommand immediately, as a substitute for the
+		 * original subcommand.  (Note, however, that this does cause
+		 * AT_AddConstraint subcommands to be rescheduled into later passes,
+		 * which is important for index and foreign key constraints.)
+		 *
+		 * We assume we needn't do any phase-1 checks for added subcommands.
+		 */
+		switch (cmd2->subtype)
+		{
+			case AT_SetNotNull:
+				/* Need command-specific recursion decision */
+				ATPrepSetNotNull(wqueue, rel, cmd2,
+								 recurse, false,
+								 lockmode, context);
+				pass = AT_PASS_COL_ATTRS;
+				break;
+			case AT_AddIndex:
+				/* This command never recurses */
+				/* No command-specific prep needed */
+				pass = AT_PASS_ADD_INDEX;
+				break;
+			case AT_AddIndexConstraint:
+				/* This command never recurses */
+				/* No command-specific prep needed */
+				pass = AT_PASS_ADD_INDEXCONSTR;
+				break;
+			case AT_AddConstraint:
+				/* Recursion occurs during execution phase */
+				if (recurse)
+					cmd2->subtype = AT_AddConstraintRecurse;
+				switch (castNode(Constraint, cmd2->def)->contype)
+				{
+					case CONSTR_PRIMARY:
+					case CONSTR_UNIQUE:
+					case CONSTR_EXCLUSION:
+						pass = AT_PASS_ADD_INDEXCONSTR;
+						break;
+					default:
+						pass = AT_PASS_ADD_OTHERCONSTR;
+						break;
+				}
+				break;
+			case AT_AlterColumnGenericOptions:
+				/* This command never recurses */
+				/* No command-specific prep needed */
+				pass = AT_PASS_MISC;
+				break;
+			default:
+				pass = cur_pass;
+				break;
+		}
+
+		if (pass < cur_pass)
+		{
+			/* Cannot schedule into a pass we already finished */
+			elog(ERROR, "ALTER TABLE scheduling failure: too late for pass %d",
+				 pass);
+		}
+		else if (pass > cur_pass)
+		{
+			/* OK, queue it up for later */
+			tab->subcmds[pass] = lappend(tab->subcmds[pass], cmd2);
+		}
+		else
+		{
+			/*
+			 * We should see at most one subcommand for the current pass,
+			 * which is the transformed version of the original subcommand.
+			 */
+			if (newcmd == NULL && cmd->subtype == cmd2->subtype)
+			{
+				/* Found the transformed version of our subcommand */
+				newcmd = cmd2;
+			}
+			else
+				elog(ERROR, "ALTER TABLE scheduling failure: bogus item for pass %d",
+					 pass);
+		}
+	}
+
+	/* Queue up any after-statements to happen at the end */
+	tab->afterStmts = list_concat(tab->afterStmts, afterStmts);
+
+	return newcmd;
+}
+
+/*
+ * ATRewriteTables: ALTER TABLE phase 3
+ */
+static void
+ATRewriteTables(AlterTableStmt *parsetree, List **wqueue, LOCKMODE lockmode,
+				AlterTableUtilityContext *context)
+{
+	ListCell   *ltab;
+
+	/* Go through each table that needs to be checked or rewritten */
+	foreach(ltab, *wqueue)
+	{
+		AlteredTableInfo *tab = (AlteredTableInfo *) lfirst(ltab);
+
+		/* Relations without storage may be ignored here */
+		if (!RELKIND_HAS_STORAGE(tab->relkind))
+			continue;
+
+		/*
+		 * If we change column data types, the operation has to be propagated
+		 * to tables that use this table's rowtype as a column type.
+		 * tab->newvals will also be non-NULL in the case where we're adding a
+		 * column with a default.  We choose to forbid that case as well,
+		 * since composite types might eventually support defaults.
+		 *
+		 * (Eventually we'll probably need to check for composite type
+		 * dependencies even when we're just scanning the table without a
+		 * rewrite, but at the moment a composite type does not enforce any
+		 * constraints, so it's not necessary/appropriate to enforce them just
+		 * during ALTER.)
+		 */
+		if (tab->newvals != NIL || tab->rewrite > 0)
+		{
+			Relation	rel;
+
+			rel = table_open(tab->relid, NoLock);
+			find_composite_type_dependencies(rel->rd_rel->reltype, rel, NULL);
+			table_close(rel, NoLock);
+		}
+
+		/*
+		 * We only need to rewrite the table if at least one column needs to
+		 * be recomputed, or we are changing its persistence or access method.
+		 *
+		 * There are two reasons for requiring a rewrite when changing
+		 * persistence: on one hand, we need to ensure that the buffers
+		 * belonging to each of the two relations are marked with or without
+		 * BM_PERMANENT properly.  On the other hand, since rewriting creates
+		 * and assigns a new relfilenode, we automatically create or drop an
+		 * init fork for the relation as appropriate.
+		 */
+		if (tab->rewrite > 0 && tab->relkind != RELKIND_SEQUENCE)
+		{
+			/* Build a temporary relation and copy data */
+			Relation	OldHeap;
+			Oid			OIDNewHeap;
+			Oid			NewAccessMethod;
+			Oid			NewTableSpace;
+			char		persistence;
+
+			OldHeap = table_open(tab->relid, NoLock);
+
+			/*
+			 * We don't support rewriting of system catalogs; there are too
+			 * many corner cases and too little benefit.  In particular this
+			 * is certainly not going to work for mapped catalogs.
+			 */
+			if (IsSystemRelation(OldHeap))
+				ereport(ERROR,
+						(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+						 errmsg("cannot rewrite system relation \"%s\"",
+								RelationGetRelationName(OldHeap))));
+
+			if (RelationIsUsedAsCatalogTable(OldHeap))
+				ereport(ERROR,
+						(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+						 errmsg("cannot rewrite table \"%s\" used as a catalog table",
+								RelationGetRelationName(OldHeap))));
+
+			/*
+			 * Don't allow rewrite on temp tables of other backends ... their
+			 * local buffer manager is not going to cope.
+			 */
+			if (RELATION_IS_OTHER_TEMP(OldHeap))
+				ereport(ERROR,
+						(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+						 errmsg("cannot rewrite temporary tables of other sessions")));
+
+			/*
+			 * Select destination tablespace (same as original unless user
+			 * requested a change)
+			 */
+			if (tab->newTableSpace)
+				NewTableSpace = tab->newTableSpace;
+			else
+				NewTableSpace = OldHeap->rd_rel->reltablespace;
+
+			/*
+			 * Select destination access method (same as original unless user
+			 * requested a change)
+			 */
+			if (OidIsValid(tab->newAccessMethod))
+				NewAccessMethod = tab->newAccessMethod;
+			else
+				NewAccessMethod = OldHeap->rd_rel->relam;
+
+			/*
+			 * Select persistence of transient table (same as original unless
+			 * user requested a change)
+			 */
+			persistence = tab->chgPersistence ?
+				tab->newrelpersistence : OldHeap->rd_rel->relpersistence;
+
+			table_close(OldHeap, NoLock);
+
+			/*
+			 * Fire off an Event Trigger now, before actually rewriting the
+			 * table.
+			 *
+			 * We don't support Event Trigger for nested commands anywhere,
+			 * here included, and parsetree is given NULL when coming from
+			 * AlterTableInternal.
+			 *
+			 * And fire it only once.
+			 */
+			if (parsetree)
+				EventTriggerTableRewrite((Node *) parsetree,
+										 tab->relid,
+										 tab->rewrite);
+
+			/*
+			 * Create transient table that will receive the modified data.
+			 *
+			 * Ensure it is marked correctly as logged or unlogged.  We have
+			 * to do this here so that buffers for the new relfilenode will
+			 * have the right persistence set, and at the same time ensure
+			 * that the original filenode's buffers will get read in with the
+			 * correct setting (i.e. the original one).  Otherwise a rollback
+			 * after the rewrite would possibly result with buffers for the
+			 * original filenode having the wrong persistence setting.
+			 *
+			 * NB: This relies on swap_relation_files() also swapping the
+			 * persistence. That wouldn't work for pg_class, but that can't be
+			 * unlogged anyway.
+			 */
+			OIDNewHeap = make_new_heap(tab->relid, NewTableSpace, NewAccessMethod,
+									   persistence, lockmode);
+
+			/*
+			 * Copy the heap data into the new table with the desired
+			 * modifications, and test the current data within the table
+			 * against new constraints generated by ALTER TABLE commands.
+			 */
+			ATRewriteTable(tab, OIDNewHeap, lockmode);
+
+			/*
+			 * Swap the physical files of the old and new heaps, then rebuild
+			 * indexes and discard the old heap.  We can use RecentXmin for
+			 * the table's new relfrozenxid because we rewrote all the tuples
+			 * in ATRewriteTable, so no older Xid remains in the table.  Also,
+			 * we never try to swap toast tables by content, since we have no
+			 * interest in letting this code work on system catalogs.
+			 */
+			finish_heap_swap(tab->relid, OIDNewHeap,
+							 false, false, true,
+							 !OidIsValid(tab->newTableSpace),
+							 RecentXmin,
+							 ReadNextMultiXactId(),
+							 persistence);
+
+			InvokeObjectPostAlterHook(RelationRelationId, tab->relid, 0);
+		}
+		else if (tab->rewrite > 0 && tab->relkind == RELKIND_SEQUENCE)
+		{
+			if (tab->chgPersistence)
+				SequenceChangePersistence(tab->relid, tab->newrelpersistence);
+		}
+		else
+		{
+			/*
+			 * If required, test the current data within the table against new
+			 * constraints generated by ALTER TABLE commands, but don't
+			 * rebuild data.
+			 */
+			if (tab->constraints != NIL || tab->verify_new_notnull ||
+				tab->partition_constraint != NULL)
+				ATRewriteTable(tab, InvalidOid, lockmode);
+
+			/*
+			 * If we had SET TABLESPACE but no reason to reconstruct tuples,
+			 * just do a block-by-block copy.
+			 */
+			if (tab->newTableSpace)
+				ATExecSetTableSpace(tab->relid, tab->newTableSpace, lockmode);
+		}
+
+		/*
+		 * Also change persistence of owned sequences, so that it matches the
+		 * table persistence.
+		 */
+		if (tab->chgPersistence)
+		{
+			List	   *seqlist = getOwnedSequences(tab->relid);
+			ListCell   *lc;
+
+			foreach(lc, seqlist)
+			{
+				Oid			seq_relid = lfirst_oid(lc);
+
+				SequenceChangePersistence(seq_relid, tab->newrelpersistence);
+			}
+		}
+	}
+
+	/*
+	 * Foreign key constraints are checked in a final pass, since (a) it's
+	 * generally best to examine each one separately, and (b) it's at least
+	 * theoretically possible that we have changed both relations of the
+	 * foreign key, and we'd better have finished both rewrites before we try
+	 * to read the tables.
+	 */
+	foreach(ltab, *wqueue)
+	{
+		AlteredTableInfo *tab = (AlteredTableInfo *) lfirst(ltab);
+		Relation	rel = NULL;
+		ListCell   *lcon;
+
+		/* Relations without storage may be ignored here too */
+		if (!RELKIND_HAS_STORAGE(tab->relkind))
+			continue;
+
+		foreach(lcon, tab->constraints)
+		{
+			NewConstraint *con = lfirst(lcon);
+
+			if (con->contype == CONSTR_FOREIGN)
+			{
+				Constraint *fkconstraint = (Constraint *) con->qual;
+				Relation	refrel;
+
+				if (rel == NULL)
+				{
+					/* Long since locked, no need for another */
+					rel = table_open(tab->relid, NoLock);
+				}
+
+				refrel = table_open(con->refrelid, RowShareLock);
+
+				validateForeignKeyConstraint(fkconstraint->conname, rel, refrel,
+											 con->refindid,
+											 con->conid);
+
+				/*
+				 * No need to mark the constraint row as validated, we did
+				 * that when we inserted the row earlier.
+				 */
+
+				table_close(refrel, NoLock);
+			}
+		}
+
+		if (rel)
+			table_close(rel, NoLock);
+	}
+
+	/* Finally, run any afterStmts that were queued up */
+	foreach(ltab, *wqueue)
+	{
+		AlteredTableInfo *tab = (AlteredTableInfo *) lfirst(ltab);
+		ListCell   *lc;
+
+		foreach(lc, tab->afterStmts)
+		{
+			Node	   *stmt = (Node *) lfirst(lc);
+
+			ProcessUtilityForAlterTable(stmt, context);
+			CommandCounterIncrement();
+		}
+	}
+}
+
+/*
+ * ATRewriteTable: scan or rewrite one table
+ *
+ * OIDNewHeap is InvalidOid if we don't need to rewrite
+ */
+static void
+ATRewriteTable(AlteredTableInfo *tab, Oid OIDNewHeap, LOCKMODE lockmode)
+{
+	Relation	oldrel;
+	Relation	newrel;
+	TupleDesc	oldTupDesc;
+	TupleDesc	newTupDesc;
+	bool		needscan = false;
+	List	   *notnull_attrs;
+	int			i;
+	ListCell   *l;
+	EState	   *estate;
+	CommandId	mycid;
+	BulkInsertState bistate;
+	int			ti_options;
+	ExprState  *partqualstate = NULL;
+
+	/*
+	 * Open the relation(s).  We have surely already locked the existing
+	 * table.
+	 */
+	oldrel = table_open(tab->relid, NoLock);
+	oldTupDesc = tab->oldDesc;
+	newTupDesc = RelationGetDescr(oldrel);	/* includes all mods */
+
+	if (OidIsValid(OIDNewHeap))
+		newrel = table_open(OIDNewHeap, lockmode);
+	else
+		newrel = NULL;
+
+	/*
+	 * Prepare a BulkInsertState and options for table_tuple_insert.  The FSM
+	 * is empty, so don't bother using it.
+	 */
+	if (newrel)
+	{
+		mycid = GetCurrentCommandId(true);
+		bistate = GetBulkInsertState();
+		ti_options = TABLE_INSERT_SKIP_FSM;
+	}
+	else
+	{
+		/* keep compiler quiet about using these uninitialized */
+		mycid = 0;
+		bistate = NULL;
+		ti_options = 0;
+	}
+
+	/*
+	 * Generate the constraint and default execution states
+	 */
+
+	estate = CreateExecutorState();
+
+	/* Build the needed expression execution states */
+	foreach(l, tab->constraints)
+	{
+		NewConstraint *con = lfirst(l);
+
+		switch (con->contype)
+		{
+			case CONSTR_CHECK:
+				needscan = true;
+				con->qualstate = ExecPrepareExpr((Expr *) con->qual, estate);
+				break;
+			case CONSTR_FOREIGN:
+				/* Nothing to do here */
+				break;
+			default:
+				elog(ERROR, "unrecognized constraint type: %d",
+					 (int) con->contype);
+		}
+	}
+
+	/* Build expression execution states for partition check quals */
+	if (tab->partition_constraint)
+	{
+		needscan = true;
+		partqualstate = ExecPrepareExpr(tab->partition_constraint, estate);
+	}
+
+	foreach(l, tab->newvals)
+	{
+		NewColumnValue *ex = lfirst(l);
+
+		/* expr already planned */
+		ex->exprstate = ExecInitExpr((Expr *) ex->expr, NULL);
+	}
+
+	notnull_attrs = NIL;
+	if (newrel || tab->verify_new_notnull)
+	{
+		/*
+		 * If we are rebuilding the tuples OR if we added any new but not
+		 * verified NOT NULL constraints, check all not-null constraints. This
+		 * is a bit of overkill but it minimizes risk of bugs, and
+		 * heap_attisnull is a pretty cheap test anyway.
+		 */
+		for (i = 0; i < newTupDesc->natts; i++)
+		{
+			Form_pg_attribute attr = TupleDescAttr(newTupDesc, i);
+
+			if (attr->attnotnull && !attr->attisdropped)
+				notnull_attrs = lappend_int(notnull_attrs, i);
+		}
+		if (notnull_attrs)
+			needscan = true;
+	}
+
+	if (newrel || needscan)
+	{
+		ExprContext *econtext;
+		TupleTableSlot *oldslot;
+		TupleTableSlot *newslot;
+		TableScanDesc scan;
+		MemoryContext oldCxt;
+		List	   *dropped_attrs = NIL;
+		ListCell   *lc;
+		Snapshot	snapshot;
+
+		if (newrel)
+			ereport(DEBUG1,
+					(errmsg_internal("rewriting table \"%s\"",
+									 RelationGetRelationName(oldrel))));
+		else
+			ereport(DEBUG1,
+					(errmsg_internal("verifying table \"%s\"",
+									 RelationGetRelationName(oldrel))));
+
+		if (newrel)
+		{
+			/*
+			 * All predicate locks on the tuples or pages are about to be made
+			 * invalid, because we move tuples around.  Promote them to
+			 * relation locks.
+			 */
+			TransferPredicateLocksToHeapRelation(oldrel);
+		}
+
+		econtext = GetPerTupleExprContext(estate);
+
+		/*
+		 * Create necessary tuple slots. When rewriting, two slots are needed,
+		 * otherwise one suffices. In the case where one slot suffices, we
+		 * need to use the new tuple descriptor, otherwise some constraints
+		 * can't be evaluated.  Note that even when the tuple layout is the
+		 * same and no rewrite is required, the tupDescs might not be
+		 * (consider ADD COLUMN without a default).
+		 */
+		if (tab->rewrite)
+		{
+			Assert(newrel != NULL);
+			oldslot = MakeSingleTupleTableSlot(oldTupDesc,
+											   table_slot_callbacks(oldrel));
+			newslot = MakeSingleTupleTableSlot(newTupDesc,
+											   table_slot_callbacks(newrel));
+
+			/*
+			 * Set all columns in the new slot to NULL initially, to ensure
+			 * columns added as part of the rewrite are initialized to NULL.
+			 * That is necessary as tab->newvals will not contain an
+			 * expression for columns with a NULL default, e.g. when adding a
+			 * column without a default together with a column with a default
+			 * requiring an actual rewrite.
+			 */
+			ExecStoreAllNullTuple(newslot);
+		}
+		else
+		{
+			oldslot = MakeSingleTupleTableSlot(newTupDesc,
+											   table_slot_callbacks(oldrel));
+			newslot = NULL;
+		}
+
+		/*
+		 * Any attributes that are dropped according to the new tuple
+		 * descriptor can be set to NULL. We precompute the list of dropped
+		 * attributes to avoid needing to do so in the per-tuple loop.
+		 */
+		for (i = 0; i < newTupDesc->natts; i++)
+		{
+			if (TupleDescAttr(newTupDesc, i)->attisdropped)
+				dropped_attrs = lappend_int(dropped_attrs, i);
+		}
+
+		/*
+		 * Scan through the rows, generating a new row if needed and then
+		 * checking all the constraints.
+		 */
+		snapshot = RegisterSnapshot(GetLatestSnapshot());
+		scan = table_beginscan(oldrel, snapshot, 0, NULL);
+
+		/*
+		 * Switch to per-tuple memory context and reset it for each tuple
+		 * produced, so we don't leak memory.
+		 */
+		oldCxt = MemoryContextSwitchTo(GetPerTupleMemoryContext(estate));
+
+		while (table_scan_getnextslot(scan, ForwardScanDirection, oldslot))
+		{
+			TupleTableSlot *insertslot;
+
+			if (tab->rewrite > 0)
+			{
+				/* Extract data from old tuple */
+				slot_getallattrs(oldslot);
+				ExecClearTuple(newslot);
+
+				/* copy attributes */
+				memcpy(newslot->tts_values, oldslot->tts_values,
+					   sizeof(Datum) * oldslot->tts_nvalid);
+				memcpy(newslot->tts_isnull, oldslot->tts_isnull,
+					   sizeof(bool) * oldslot->tts_nvalid);
+
+				/* Set dropped attributes to null in new tuple */
+				foreach(lc, dropped_attrs)
+					newslot->tts_isnull[lfirst_int(lc)] = true;
+
+				/*
+				 * Constraints and GENERATED expressions might reference the
+				 * tableoid column, so fill tts_tableOid with the desired
+				 * value.  (We must do this each time, because it gets
+				 * overwritten with newrel's OID during storing.)
+				 */
+				newslot->tts_tableOid = RelationGetRelid(oldrel);
+
+				/*
+				 * Process supplied expressions to replace selected columns.
+				 *
+				 * First, evaluate expressions whose inputs come from the old
+				 * tuple.
+				 */
+				econtext->ecxt_scantuple = oldslot;
+
+				foreach(l, tab->newvals)
+				{
+					NewColumnValue *ex = lfirst(l);
+
+					if (ex->is_generated)
+						continue;
+
+					newslot->tts_values[ex->attnum - 1]
+						= ExecEvalExpr(ex->exprstate,
+									   econtext,
+									   &newslot->tts_isnull[ex->attnum - 1]);
+				}
+
+				ExecStoreVirtualTuple(newslot);
+
+				/*
+				 * Now, evaluate any expressions whose inputs come from the
+				 * new tuple.  We assume these columns won't reference each
+				 * other, so that there's no ordering dependency.
+				 */
+				econtext->ecxt_scantuple = newslot;
+
+				foreach(l, tab->newvals)
+				{
+					NewColumnValue *ex = lfirst(l);
+
+					if (!ex->is_generated)
+						continue;
+
+					newslot->tts_values[ex->attnum - 1]
+						= ExecEvalExpr(ex->exprstate,
+									   econtext,
+									   &newslot->tts_isnull[ex->attnum - 1]);
+				}
+
+				insertslot = newslot;
+			}
+			else
+			{
+				/*
+				 * If there's no rewrite, old and new table are guaranteed to
+				 * have the same AM, so we can just use the old slot to verify
+				 * new constraints etc.
+				 */
+				insertslot = oldslot;
+			}
+
+			/* Now check any constraints on the possibly-changed tuple */
+			econtext->ecxt_scantuple = insertslot;
+
+			foreach(l, notnull_attrs)
+			{
+				int			attn = lfirst_int(l);
+
+				if (slot_attisnull(insertslot, attn + 1))
+				{
+					Form_pg_attribute attr = TupleDescAttr(newTupDesc, attn);
+
+					ereport(ERROR,
+							(errcode(ERRCODE_NOT_NULL_VIOLATION),
+							 errmsg("column \"%s\" of relation \"%s\" contains null values",
+									NameStr(attr->attname),
+									RelationGetRelationName(oldrel)),
+							 errtablecol(oldrel, attn + 1)));
+				}
+			}
+
+			foreach(l, tab->constraints)
+			{
+				NewConstraint *con = lfirst(l);
+
+				switch (con->contype)
+				{
+					case CONSTR_CHECK:
+						if (!ExecCheck(con->qualstate, econtext))
+							ereport(ERROR,
+									(errcode(ERRCODE_CHECK_VIOLATION),
+									 errmsg("check constraint \"%s\" of relation \"%s\" is violated by some row",
+											con->name,
+											RelationGetRelationName(oldrel)),
+									 errtableconstraint(oldrel, con->name)));
+						break;
+					case CONSTR_FOREIGN:
+						/* Nothing to do here */
+						break;
+					default:
+						elog(ERROR, "unrecognized constraint type: %d",
+							 (int) con->contype);
+				}
+			}
+
+			if (partqualstate && !ExecCheck(partqualstate, econtext))
+			{
+				if (tab->validate_default)
+					ereport(ERROR,
+							(errcode(ERRCODE_CHECK_VIOLATION),
+							 errmsg("updated partition constraint for default partition \"%s\" would be violated by some row",
+									RelationGetRelationName(oldrel)),
+							 errtable(oldrel)));
+				else
+					ereport(ERROR,
+							(errcode(ERRCODE_CHECK_VIOLATION),
+							 errmsg("partition constraint of relation \"%s\" is violated by some row",
+									RelationGetRelationName(oldrel)),
+							 errtable(oldrel)));
+			}
+
+			/* Write the tuple out to the new relation */
+			if (newrel)
+				table_tuple_insert(newrel, insertslot, mycid,
+								   ti_options, bistate);
+
+			ResetExprContext(econtext);
+
+			CHECK_FOR_INTERRUPTS();
+		}
+
+		MemoryContextSwitchTo(oldCxt);
+		table_endscan(scan);
+		UnregisterSnapshot(snapshot);
+
+		ExecDropSingleTupleTableSlot(oldslot);
+		if (newslot)
+			ExecDropSingleTupleTableSlot(newslot);
+	}
+
+	FreeExecutorState(estate);
+
+	table_close(oldrel, NoLock);
+	if (newrel)
+	{
+		FreeBulkInsertState(bistate);
+
+		table_finish_bulk_insert(newrel, ti_options);
+
+		table_close(newrel, NoLock);
+	}
+}
+
+/*
+ * ATGetQueueEntry: find or create an entry in the ALTER TABLE work queue
+ */
+static AlteredTableInfo *
+ATGetQueueEntry(List **wqueue, Relation rel)
+{
+	Oid			relid = RelationGetRelid(rel);
+	AlteredTableInfo *tab;
+	ListCell   *ltab;
+
+	foreach(ltab, *wqueue)
+	{
+		tab = (AlteredTableInfo *) lfirst(ltab);
+		if (tab->relid == relid)
+			return tab;
+	}
+
+	/*
+	 * Not there, so add it.  Note that we make a copy of the relation's
+	 * existing descriptor before anything interesting can happen to it.
+	 */
+	tab = (AlteredTableInfo *) palloc0(sizeof(AlteredTableInfo));
+	tab->relid = relid;
+	tab->rel = NULL;			/* set later */
+	tab->relkind = rel->rd_rel->relkind;
+	tab->oldDesc = CreateTupleDescCopyConstr(RelationGetDescr(rel));
+	tab->newAccessMethod = InvalidOid;
+	tab->newTableSpace = InvalidOid;
+	tab->newrelpersistence = RELPERSISTENCE_PERMANENT;
+	tab->chgPersistence = false;
+
+	*wqueue = lappend(*wqueue, tab);
+
+	return tab;
+}
+
+static const char *
+alter_table_type_to_string(AlterTableType cmdtype)
+{
+	switch (cmdtype)
+	{
+		case AT_AddColumn:
+		case AT_AddColumnRecurse:
+		case AT_AddColumnToView:
+			return "ADD COLUMN";
+		case AT_ColumnDefault:
+		case AT_CookedColumnDefault:
+			return "ALTER COLUMN ... SET DEFAULT";
+		case AT_DropNotNull:
+			return "ALTER COLUMN ... DROP NOT NULL";
+		case AT_SetNotNull:
+			return "ALTER COLUMN ... SET NOT NULL";
+		case AT_DropExpression:
+			return "ALTER COLUMN ... DROP EXPRESSION";
+		case AT_CheckNotNull:
+			return NULL;		/* not real grammar */
+		case AT_SetStatistics:
+			return "ALTER COLUMN ... SET STATISTICS";
+		case AT_SetOptions:
+			return "ALTER COLUMN ... SET";
+		case AT_ResetOptions:
+			return "ALTER COLUMN ... RESET";
+		case AT_SetStorage:
+			return "ALTER COLUMN ... SET STORAGE";
+		case AT_SetCompression:
+			return "ALTER COLUMN ... SET COMPRESSION";
+		case AT_DropColumn:
+		case AT_DropColumnRecurse:
+			return "DROP COLUMN";
+		case AT_AddIndex:
+		case AT_ReAddIndex:
+			return NULL;		/* not real grammar */
+		case AT_AddConstraint:
+		case AT_AddConstraintRecurse:
+		case AT_ReAddConstraint:
+		case AT_ReAddDomainConstraint:
+		case AT_AddIndexConstraint:
+			return "ADD CONSTRAINT";
+		case AT_AlterConstraint:
+			return "ALTER CONSTRAINT";
+		case AT_ValidateConstraint:
+		case AT_ValidateConstraintRecurse:
+			return "VALIDATE CONSTRAINT";
+		case AT_DropConstraint:
+		case AT_DropConstraintRecurse:
+			return "DROP CONSTRAINT";
+		case AT_ReAddComment:
+			return NULL;		/* not real grammar */
+		case AT_AlterColumnType:
+			return "ALTER COLUMN ... SET DATA TYPE";
+		case AT_AlterColumnGenericOptions:
+			return "ALTER COLUMN ... OPTIONS";
+		case AT_ChangeOwner:
+			return "OWNER TO";
+		case AT_ClusterOn:
+			return "CLUSTER ON";
+		case AT_DropCluster:
+			return "SET WITHOUT CLUSTER";
+		case AT_SetAccessMethod:
+			return "SET ACCESS METHOD";
+		case AT_SetLogged:
+			return "SET LOGGED";
+		case AT_SetUnLogged:
+			return "SET UNLOGGED";
+		case AT_DropOids:
+			return "SET WITHOUT OIDS";
+		case AT_SetTableSpace:
+			return "SET TABLESPACE";
+		case AT_SetRelOptions:
+			return "SET";
+		case AT_ResetRelOptions:
+			return "RESET";
+		case AT_ReplaceRelOptions:
+			return NULL;		/* not real grammar */
+		case AT_EnableTrig:
+			return "ENABLE TRIGGER";
+		case AT_EnableAlwaysTrig:
+			return "ENABLE ALWAYS TRIGGER";
+		case AT_EnableReplicaTrig:
+			return "ENABLE REPLICA TRIGGER";
+		case AT_DisableTrig:
+			return "DISABLE TRIGGER";
+		case AT_EnableTrigAll:
+			return "ENABLE TRIGGER ALL";
+		case AT_DisableTrigAll:
+			return "DISABLE TRIGGER ALL";
+		case AT_EnableTrigUser:
+			return "ENABLE TRIGGER USER";
+		case AT_DisableTrigUser:
+			return "DISABLE TRIGGER USER";
+		case AT_EnableRule:
+			return "ENABLE RULE";
+		case AT_EnableAlwaysRule:
+			return "ENABLE ALWAYS RULE";
+		case AT_EnableReplicaRule:
+			return "ENABLE REPLICA RULE";
+		case AT_DisableRule:
+			return "DISABLE RULE";
+		case AT_AddInherit:
+			return "INHERIT";
+		case AT_DropInherit:
+			return "NO INHERIT";
+		case AT_AddOf:
+			return "OF";
+		case AT_DropOf:
+			return "NOT OF";
+		case AT_ReplicaIdentity:
+			return "REPLICA IDENTITY";
+		case AT_EnableRowSecurity:
+			return "ENABLE ROW SECURITY";
+		case AT_DisableRowSecurity:
+			return "DISABLE ROW SECURITY";
+		case AT_ForceRowSecurity:
+			return "FORCE ROW SECURITY";
+		case AT_NoForceRowSecurity:
+			return "NO FORCE ROW SECURITY";
+		case AT_GenericOptions:
+			return "OPTIONS";
+		case AT_AttachPartition:
+			return "ATTACH PARTITION";
+		case AT_DetachPartition:
+			return "DETACH PARTITION";
+		case AT_DetachPartitionFinalize:
+			return "DETACH PARTITION ... FINALIZE";
+		case AT_AddIdentity:
+			return "ALTER COLUMN ... ADD IDENTITY";
+		case AT_SetIdentity:
+			return "ALTER COLUMN ... SET";
+		case AT_DropIdentity:
+			return "ALTER COLUMN ... DROP IDENTITY";
+		case AT_ReAddStatistics:
+			return NULL;		/* not real grammar */
+	}
+
+	return NULL;
+}
+
+/*
+ * ATSimplePermissions
+ *
+ * - Ensure that it is a relation (or possibly a view)
+ * - Ensure this user is the owner
+ * - Ensure that it is not a system table
+ */
+static void
+ATSimplePermissions(AlterTableType cmdtype, Relation rel, int allowed_targets)
+{
+	int			actual_target;
+
+	switch (rel->rd_rel->relkind)
+	{
+		case RELKIND_RELATION:
+		case RELKIND_PARTITIONED_TABLE:
+			actual_target = ATT_TABLE;
+			break;
+		case RELKIND_VIEW:
+			actual_target = ATT_VIEW;
+			break;
+		case RELKIND_MATVIEW:
+			actual_target = ATT_MATVIEW;
+			break;
+		case RELKIND_INDEX:
+			actual_target = ATT_INDEX;
+			break;
+		case RELKIND_PARTITIONED_INDEX:
+			actual_target = ATT_PARTITIONED_INDEX;
+			break;
+		case RELKIND_COMPOSITE_TYPE:
+			actual_target = ATT_COMPOSITE_TYPE;
+			break;
+		case RELKIND_FOREIGN_TABLE:
+			actual_target = ATT_FOREIGN_TABLE;
+			break;
+		case RELKIND_SEQUENCE:
+			actual_target = ATT_SEQUENCE;
+			break;
+		default:
+			actual_target = 0;
+			break;
+	}
+
+	/* Wrong target type? */
+	if ((actual_target & allowed_targets) == 0)
+	{
+		const char *action_str = alter_table_type_to_string(cmdtype);
+
+		if (action_str)
+			ereport(ERROR,
+					(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+			/* translator: %s is a group of some SQL keywords */
+					 errmsg("ALTER action %s cannot be performed on relation \"%s\"",
+							action_str, RelationGetRelationName(rel)),
+					 errdetail_relkind_not_supported(rel->rd_rel->relkind)));
+		else
+			/* internal error? */
+			elog(ERROR, "invalid ALTER action attempted on relation \"%s\"",
+				 RelationGetRelationName(rel));
+	}
+
+	/* Permissions checks */
+	if (!pg_class_ownercheck(RelationGetRelid(rel), GetUserId()))
+		aclcheck_error(ACLCHECK_NOT_OWNER, get_relkind_objtype(rel->rd_rel->relkind),
+					   RelationGetRelationName(rel));
+
+	if (!allowSystemTableMods && IsSystemRelation(rel))
+		ereport(ERROR,
+				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
+				 errmsg("permission denied: \"%s\" is a system catalog",
+						RelationGetRelationName(rel))));
+}
+
+/*
+ * ATSimpleRecursion
+ *
+ * Simple table recursion sufficient for most ALTER TABLE operations.
+ * All direct and indirect children are processed in an unspecified order.
+ * Note that if a child inherits from the original table via multiple
+ * inheritance paths, it will be visited just once.
+ */
+static void
+ATSimpleRecursion(List **wqueue, Relation rel,
+				  AlterTableCmd *cmd, bool recurse, LOCKMODE lockmode,
+				  AlterTableUtilityContext *context)
+{
+	/*
+	 * Propagate to children, if desired and if there are (or might be) any
+	 * children.
+	 */
+	if (recurse && rel->rd_rel->relhassubclass)
+	{
+		Oid			relid = RelationGetRelid(rel);
+		ListCell   *child;
+		List	   *children;
+
+		children = find_all_inheritors(relid, lockmode, NULL);
+
+		/*
+		 * find_all_inheritors does the recursive search of the inheritance
+		 * hierarchy, so all we have to do is process all of the relids in the
+		 * list that it returns.
+		 */
+		foreach(child, children)
+		{
+			Oid			childrelid = lfirst_oid(child);
+			Relation	childrel;
+
+			if (childrelid == relid)
+				continue;
+			/* find_all_inheritors already got lock */
+			childrel = relation_open(childrelid, NoLock);
+			CheckTableNotInUse(childrel, "ALTER TABLE");
+			ATPrepCmd(wqueue, childrel, cmd, false, true, lockmode, context);
+			relation_close(childrel, NoLock);
+		}
+	}
+}
+
+/*
+ * Obtain list of partitions of the given table, locking them all at the given
+ * lockmode and ensuring that they all pass CheckTableNotInUse.
+ *
+ * This function is a no-op if the given relation is not a partitioned table;
+ * in particular, nothing is done if it's a legacy inheritance parent.
+ */
+static void
+ATCheckPartitionsNotInUse(Relation rel, LOCKMODE lockmode)
+{
+	if (rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
+	{
+		List	   *inh;
+		ListCell   *cell;
+
+		inh = find_all_inheritors(RelationGetRelid(rel), lockmode, NULL);
+		/* first element is the parent rel; must ignore it */
+		for_each_from(cell, inh, 1)
+		{
+			Relation	childrel;
+
+			/* find_all_inheritors already got lock */
+			childrel = table_open(lfirst_oid(cell), NoLock);
+			CheckTableNotInUse(childrel, "ALTER TABLE");
+			table_close(childrel, NoLock);
+		}
+		list_free(inh);
+	}
+}
+
+/*
+ * ATTypedTableRecursion
+ *
+ * Propagate ALTER TYPE operations to the typed tables of that type.
+ * Also check the RESTRICT/CASCADE behavior.  Given CASCADE, also permit
+ * recursion to inheritance children of the typed tables.
+ */
+static void
+ATTypedTableRecursion(List **wqueue, Relation rel, AlterTableCmd *cmd,
+					  LOCKMODE lockmode, AlterTableUtilityContext *context)
+{
+	ListCell   *child;
+	List	   *children;
+
+	Assert(rel->rd_rel->relkind == RELKIND_COMPOSITE_TYPE);
+
+	children = find_typed_table_dependencies(rel->rd_rel->reltype,
+											 RelationGetRelationName(rel),
+											 cmd->behavior);
+
+	foreach(child, children)
+	{
+		Oid			childrelid = lfirst_oid(child);
+		Relation	childrel;
+
+		childrel = relation_open(childrelid, lockmode);
+		CheckTableNotInUse(childrel, "ALTER TABLE");
+		ATPrepCmd(wqueue, childrel, cmd, true, true, lockmode, context);
+		relation_close(childrel, NoLock);
+	}
+}
+
+
+/*
+ * find_composite_type_dependencies
+ *
+ * Check to see if the type "typeOid" is being used as a column in some table
+ * (possibly nested several levels deep in composite types, arrays, etc!).
+ * Eventually, we'd like to propagate the check or rewrite operation
+ * into such tables, but for now, just error out if we find any.
+ *
+ * Caller should provide either the associated relation of a rowtype,
+ * or a type name (not both) for use in the error message, if any.
+ *
+ * Note that "typeOid" is not necessarily a composite type; it could also be
+ * another container type such as an array or range, or a domain over one of
+ * these things.  The name of this function is therefore somewhat historical,
+ * but it's not worth changing.
+ *
+ * We assume that functions and views depending on the type are not reasons
+ * to reject the ALTER.  (How safe is this really?)
+ */
+void
+find_composite_type_dependencies(Oid typeOid, Relation origRelation,
+								 const char *origTypeName)
+{
+	Relation	depRel;
+	ScanKeyData key[2];
+	SysScanDesc depScan;
+	HeapTuple	depTup;
+
+	/* since this function recurses, it could be driven to stack overflow */
+	check_stack_depth();
+
+	/*
+	 * We scan pg_depend to find those things that depend on the given type.
+	 * (We assume we can ignore refobjsubid for a type.)
+	 */
+	depRel = table_open(DependRelationId, AccessShareLock);
+
+	ScanKeyInit(&key[0],
+				Anum_pg_depend_refclassid,
+				BTEqualStrategyNumber, F_OIDEQ,
+				ObjectIdGetDatum(TypeRelationId));
+	ScanKeyInit(&key[1],
+				Anum_pg_depend_refobjid,
+				BTEqualStrategyNumber, F_OIDEQ,
+				ObjectIdGetDatum(typeOid));
+
+	depScan = systable_beginscan(depRel, DependReferenceIndexId, true,
+								 NULL, 2, key);
+
+	while (HeapTupleIsValid(depTup = systable_getnext(depScan)))
+	{
+		Form_pg_depend pg_depend = (Form_pg_depend) GETSTRUCT(depTup);
+		Relation	rel;
+		TupleDesc	tupleDesc;
+		Form_pg_attribute att;
+
+		/* Check for directly dependent types */
+		if (pg_depend->classid == TypeRelationId)
+		{
+			/*
+			 * This must be an array, domain, or range containing the given
+			 * type, so recursively check for uses of this type.  Note that
+			 * any error message will mention the original type not the
+			 * container; this is intentional.
+			 */
+			find_composite_type_dependencies(pg_depend->objid,
+											 origRelation, origTypeName);
+			continue;
+		}
+
+		/* Else, ignore dependees that aren't relations */
+		if (pg_depend->classid != RelationRelationId)
+			continue;
+
+		rel = relation_open(pg_depend->objid, AccessShareLock);
+		tupleDesc = RelationGetDescr(rel);
+
+		/*
+		 * If objsubid identifies a specific column, refer to that in error
+		 * messages.  Otherwise, search to see if there's a user column of the
+		 * type.  (We assume system columns are never of interesting types.)
+		 * The search is needed because an index containing an expression
+		 * column of the target type will just be recorded as a whole-relation
+		 * dependency.  If we do not find a column of the type, the dependency
+		 * must indicate that the type is transiently referenced in an index
+		 * expression but not stored on disk, which we assume is OK, just as
+		 * we do for references in views.  (It could also be that the target
+		 * type is embedded in some container type that is stored in an index
+		 * column, but the previous recursion should catch such cases.)
+		 */
+		if (pg_depend->objsubid > 0 && pg_depend->objsubid <= tupleDesc->natts)
+			att = TupleDescAttr(tupleDesc, pg_depend->objsubid - 1);
+		else
+		{
+			att = NULL;
+			for (int attno = 1; attno <= tupleDesc->natts; attno++)
+			{
+				att = TupleDescAttr(tupleDesc, attno - 1);
+				if (att->atttypid == typeOid && !att->attisdropped)
+					break;
+				att = NULL;
+			}
+			if (att == NULL)
+			{
+				/* No such column, so assume OK */
+				relation_close(rel, AccessShareLock);
+				continue;
+			}
+		}
+
+		/*
+		 * We definitely should reject if the relation has storage.  If it's
+		 * partitioned, then perhaps we don't have to reject: if there are
+		 * partitions then we'll fail when we find one, else there is no
+		 * stored data to worry about.  However, it's possible that the type
+		 * change would affect conclusions about whether the type is sortable
+		 * or hashable and thus (if it's a partitioning column) break the
+		 * partitioning rule.  For now, reject for partitioned rels too.
+		 */
+		if (RELKIND_HAS_STORAGE(rel->rd_rel->relkind) ||
+			RELKIND_HAS_PARTITIONS(rel->rd_rel->relkind))
+		{
+			if (origTypeName)
+				ereport(ERROR,
+						(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+						 errmsg("cannot alter type \"%s\" because column \"%s.%s\" uses it",
+								origTypeName,
+								RelationGetRelationName(rel),
+								NameStr(att->attname))));
+			else if (origRelation->rd_rel->relkind == RELKIND_COMPOSITE_TYPE)
+				ereport(ERROR,
+						(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+						 errmsg("cannot alter type \"%s\" because column \"%s.%s\" uses it",
+								RelationGetRelationName(origRelation),
+								RelationGetRelationName(rel),
+								NameStr(att->attname))));
+			else if (origRelation->rd_rel->relkind == RELKIND_FOREIGN_TABLE)
+				ereport(ERROR,
+						(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+						 errmsg("cannot alter foreign table \"%s\" because column \"%s.%s\" uses its row type",
+								RelationGetRelationName(origRelation),
+								RelationGetRelationName(rel),
+								NameStr(att->attname))));
+			else
+				ereport(ERROR,
+						(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+						 errmsg("cannot alter table \"%s\" because column \"%s.%s\" uses its row type",
+								RelationGetRelationName(origRelation),
+								RelationGetRelationName(rel),
+								NameStr(att->attname))));
+		}
+		else if (OidIsValid(rel->rd_rel->reltype))
+		{
+			/*
+			 * A view or composite type itself isn't a problem, but we must
+			 * recursively check for indirect dependencies via its rowtype.
+			 */
+			find_composite_type_dependencies(rel->rd_rel->reltype,
+											 origRelation, origTypeName);
+		}
+
+		relation_close(rel, AccessShareLock);
+	}
+
+	systable_endscan(depScan);
+
+	relation_close(depRel, AccessShareLock);
+}
+
+
+/*
+ * find_typed_table_dependencies
+ *
+ * Check to see if a composite type is being used as the type of a
+ * typed table.  Abort if any are found and behavior is RESTRICT.
+ * Else return the list of tables.
+ */
+static List *
+find_typed_table_dependencies(Oid typeOid, const char *typeName, DropBehavior behavior)
+{
+	Relation	classRel;
+	ScanKeyData key[1];
+	TableScanDesc scan;
+	HeapTuple	tuple;
+	List	   *result = NIL;
+
+	classRel = table_open(RelationRelationId, AccessShareLock);
+
+	ScanKeyInit(&key[0],
+				Anum_pg_class_reloftype,
+				BTEqualStrategyNumber, F_OIDEQ,
+				ObjectIdGetDatum(typeOid));
+
+	scan = table_beginscan_catalog(classRel, 1, key);
+
+	while ((tuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
+	{
+		Form_pg_class classform = (Form_pg_class) GETSTRUCT(tuple);
+
+		if (behavior == DROP_RESTRICT)
+			ereport(ERROR,
+					(errcode(ERRCODE_DEPENDENT_OBJECTS_STILL_EXIST),
+					 errmsg("cannot alter type \"%s\" because it is the type of a typed table",
+							typeName),
+					 errhint("Use ALTER ... CASCADE to alter the typed tables too.")));
+		else
+			result = lappend_oid(result, classform->oid);
+	}
+
+	table_endscan(scan);
+	table_close(classRel, AccessShareLock);
+
+	return result;
+}
+
+
+/*
+ * check_of_type
+ *
+ * Check whether a type is suitable for CREATE TABLE OF/ALTER TABLE OF.  If it
+ * isn't suitable, throw an error.  Currently, we require that the type
+ * originated with CREATE TYPE AS.  We could support any row type, but doing so
+ * would require handling a number of extra corner cases in the DDL commands.
+ * (Also, allowing domain-over-composite would open up a can of worms about
+ * whether and how the domain's constraints should apply to derived tables.)
+ */
+void
+check_of_type(HeapTuple typetuple)
+{
+	Form_pg_type typ = (Form_pg_type) GETSTRUCT(typetuple);
+	bool		typeOk = false;
+
+	if (typ->typtype == TYPTYPE_COMPOSITE)
+	{
+		Relation	typeRelation;
+
+		Assert(OidIsValid(typ->typrelid));
+		typeRelation = relation_open(typ->typrelid, AccessShareLock);
+		typeOk = (typeRelation->rd_rel->relkind == RELKIND_COMPOSITE_TYPE);
+
+		/*
+		 * Close the parent rel, but keep our AccessShareLock on it until xact
+		 * commit.  That will prevent someone else from deleting or ALTERing
+		 * the type before the typed table creation/conversion commits.
+		 */
+		relation_close(typeRelation, NoLock);
+	}
+	if (!typeOk)
+		ereport(ERROR,
+				(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+				 errmsg("type %s is not a composite type",
+						format_type_be(typ->oid))));
+}
+
+
+/*
+ * ALTER TABLE ADD COLUMN
+ *
+ * Adds an additional attribute to a relation making the assumption that
+ * CHECK, NOT NULL, and FOREIGN KEY constraints will be removed from the
+ * AT_AddColumn AlterTableCmd by parse_utilcmd.c and added as independent
+ * AlterTableCmd's.
+ *
+ * ADD COLUMN cannot use the normal ALTER TABLE recursion mechanism, because we
+ * have to decide at runtime whether to recurse or not depending on whether we
+ * actually add a column or merely merge with an existing column.  (We can't
+ * check this in a static pre-pass because it won't handle multiple inheritance
+ * situations correctly.)
+ */
+static void
+ATPrepAddColumn(List **wqueue, Relation rel, bool recurse, bool recursing,
+				bool is_view, AlterTableCmd *cmd, LOCKMODE lockmode,
+				AlterTableUtilityContext *context)
+{
+	if (rel->rd_rel->reloftype && !recursing)
+		ereport(ERROR,
+				(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+				 errmsg("cannot add column to typed table")));
+
+	if (rel->rd_rel->relkind == RELKIND_COMPOSITE_TYPE)
+		ATTypedTableRecursion(wqueue, rel, cmd, lockmode, context);
+
+	if (recurse && !is_view)
+		cmd->subtype = AT_AddColumnRecurse;
+}
+
+/*
+ * Add a column to a table.  The return value is the address of the
+ * new column in the parent relation.
+ *
+ * cmd is pass-by-ref so that we can replace it with the parse-transformed
+ * copy (but that happens only after we check for IF NOT EXISTS).
+ */
+static ObjectAddress
+ATExecAddColumn(List **wqueue, AlteredTableInfo *tab, Relation rel,
+				AlterTableCmd **cmd,
+				bool recurse, bool recursing,
+				LOCKMODE lockmode, int cur_pass,
+				AlterTableUtilityContext *context)
+{
+	Oid			myrelid = RelationGetRelid(rel);
+	ColumnDef  *colDef = castNode(ColumnDef, (*cmd)->def);
+	bool		if_not_exists = (*cmd)->missing_ok;
+	Relation	pgclass,
+				attrdesc;
+	HeapTuple	reltup;
+	FormData_pg_attribute attribute;
+	int			newattnum;
+	char		relkind;
+	HeapTuple	typeTuple;
+	Oid			typeOid;
+	int32		typmod;
+	Oid			collOid;
+	Form_pg_type tform;
+	Expr	   *defval;
+	List	   *children;
+	ListCell   *child;
+	AlterTableCmd *childcmd;
+	AclResult	aclresult;
+	ObjectAddress address;
+	TupleDesc	tupdesc;
+	FormData_pg_attribute *aattr[] = {&attribute};
+
+	/* At top level, permission check was done in ATPrepCmd, else do it */
+	if (recursing)
+		ATSimplePermissions((*cmd)->subtype, rel, ATT_TABLE | ATT_FOREIGN_TABLE);
+
+	if (rel->rd_rel->relispartition && !recursing)
+		ereport(ERROR,
+				(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+				 errmsg("cannot add column to a partition")));
+
+	attrdesc = table_open(AttributeRelationId, RowExclusiveLock);
+
+	/*
+	 * Are we adding the column to a recursion child?  If so, check whether to
+	 * merge with an existing definition for the column.  If we do merge, we
+	 * must not recurse.  Children will already have the column, and recursing
+	 * into them would mess up attinhcount.
+	 */
+	if (colDef->inhcount > 0)
+	{
+		HeapTuple	tuple;
+
+		/* Does child already have a column by this name? */
+		tuple = SearchSysCacheCopyAttName(myrelid, colDef->colname);
+		if (HeapTupleIsValid(tuple))
+		{
+			Form_pg_attribute childatt = (Form_pg_attribute) GETSTRUCT(tuple);
+			Oid			ctypeId;
+			int32		ctypmod;
+			Oid			ccollid;
+
+			/* Child column must match on type, typmod, and collation */
+			typenameTypeIdAndMod(NULL, colDef->typeName, &ctypeId, &ctypmod);
+			if (ctypeId != childatt->atttypid ||
+				ctypmod != childatt->atttypmod)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("child table \"%s\" has different type for column \"%s\"",
+								RelationGetRelationName(rel), colDef->colname)));
+			ccollid = GetColumnDefCollation(NULL, colDef, ctypeId);
+			if (ccollid != childatt->attcollation)
+				ereport(ERROR,
+						(errcode(ERRCODE_COLLATION_MISMATCH),
+						 errmsg("child table \"%s\" has different collation for column \"%s\"",
+								RelationGetRelationName(rel), colDef->colname),
+						 errdetail("\"%s\" versus \"%s\"",
+								   get_collation_name(ccollid),
+								   get_collation_name(childatt->attcollation))));
+
+			/* Bump the existing child att's inhcount */
+			childatt->attinhcount++;
+			CatalogTupleUpdate(attrdesc, &tuple->t_self, tuple);
+
+			heap_freetuple(tuple);
+
+			/* Inform the user about the merge */
+			ereport(NOTICE,
+					(errmsg("merging definition of column \"%s\" for child \"%s\"",
+							colDef->colname, RelationGetRelationName(rel))));
+
+			table_close(attrdesc, RowExclusiveLock);
+			return InvalidObjectAddress;
+		}
+	}
+
+	/* skip if the name already exists and if_not_exists is true */
+	if (!check_for_column_name_collision(rel, colDef->colname, if_not_exists))
+	{
+		table_close(attrdesc, RowExclusiveLock);
+		return InvalidObjectAddress;
+	}
+
+	/*
+	 * Okay, we need to add the column, so go ahead and do parse
+	 * transformation.  This can result in queueing up, or even immediately
+	 * executing, subsidiary operations (such as creation of unique indexes);
+	 * so we mustn't do it until we have made the if_not_exists check.
+	 *
+	 * When recursing, the command was already transformed and we needn't do
+	 * so again.  Also, if context isn't given we can't transform.  (That
+	 * currently happens only for AT_AddColumnToView; we expect that view.c
+	 * passed us a ColumnDef that doesn't need work.)
+	 */
+	if (context != NULL && !recursing)
+	{
+		*cmd = ATParseTransformCmd(wqueue, tab, rel, *cmd, recurse, lockmode,
+								   cur_pass, context);
+		Assert(*cmd != NULL);
+		colDef = castNode(ColumnDef, (*cmd)->def);
+	}
+
+	/*
+	 * Cannot add identity column if table has children, because identity does
+	 * not inherit.  (Adding column and identity separately will work.)
+	 */
+	if (colDef->identity &&
+		recurse &&
+		find_inheritance_children(myrelid, NoLock) != NIL)
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
+				 errmsg("cannot recursively add identity column to table that has child tables")));
+
+	pgclass = table_open(RelationRelationId, RowExclusiveLock);
+
+	reltup = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(myrelid));
+	if (!HeapTupleIsValid(reltup))
+		elog(ERROR, "cache lookup failed for relation %u", myrelid);
+	relkind = ((Form_pg_class) GETSTRUCT(reltup))->relkind;
+
+	/* Determine the new attribute's number */
+	newattnum = ((Form_pg_class) GETSTRUCT(reltup))->relnatts + 1;
+	if (newattnum > MaxHeapAttributeNumber)
+		ereport(ERROR,
+				(errcode(ERRCODE_TOO_MANY_COLUMNS),
+				 errmsg("tables can have at most %d columns",
+						MaxHeapAttributeNumber)));
+
+	typeTuple = typenameType(NULL, colDef->typeName, &typmod);
+	tform = (Form_pg_type) GETSTRUCT(typeTuple);
+	typeOid = tform->oid;
+
+	aclresult = pg_type_aclcheck(typeOid, GetUserId(), ACL_USAGE);
+	if (aclresult != ACLCHECK_OK)
+		aclcheck_error_type(aclresult, typeOid);
+
+	collOid = GetColumnDefCollation(NULL, colDef, typeOid);
+
+	/* make sure datatype is legal for a column */
+	CheckAttributeType(colDef->colname, typeOid, collOid,
+					   list_make1_oid(rel->rd_rel->reltype),
+					   0);
+
+	/*
+	 * Construct new attribute's pg_attribute entry.  (Variable-length fields
+	 * are handled by InsertPgAttributeTuples().)
+	 */
+	attribute.attrelid = myrelid;
+	namestrcpy(&(attribute.attname), colDef->colname);
+	attribute.atttypid = typeOid;
+	attribute.attstattarget = (newattnum > 0) ? -1 : 0;
+	attribute.attlen = tform->typlen;
+	attribute.attnum = newattnum;
+	attribute.attndims = list_length(colDef->typeName->arrayBounds);
+	attribute.atttypmod = typmod;
+	attribute.attbyval = tform->typbyval;
+	attribute.attalign = tform->typalign;
+	attribute.attstorage = tform->typstorage;
+	attribute.attcompression = GetAttributeCompression(typeOid,
+													   colDef->compression);
+	attribute.attnotnull = colDef->is_not_null;
+	attribute.atthasdef = false;
+	attribute.atthasmissing = false;
+	attribute.attidentity = colDef->identity;
+	attribute.attgenerated = colDef->generated;
+	attribute.attisdropped = false;
+	attribute.attislocal = colDef->is_local;
+	attribute.attinhcount = colDef->inhcount;
+	attribute.attcollation = collOid;
+
+	ReleaseSysCache(typeTuple);
+
+	tupdesc = CreateTupleDesc(lengthof(aattr), (FormData_pg_attribute **) &aattr);
+
+	InsertPgAttributeTuples(attrdesc, tupdesc, myrelid, NULL, NULL);
+
+	table_close(attrdesc, RowExclusiveLock);
+
+	/*
+	 * Update pg_class tuple as appropriate
+	 */
+	((Form_pg_class) GETSTRUCT(reltup))->relnatts = newattnum;
+
+	CatalogTupleUpdate(pgclass, &reltup->t_self, reltup);
+
+	heap_freetuple(reltup);
+
+	/* Post creation hook for new attribute */
+	InvokeObjectPostCreateHook(RelationRelationId, myrelid, newattnum);
+
+	table_close(pgclass, RowExclusiveLock);
+
+	/* Make the attribute's catalog entry visible */
+	CommandCounterIncrement();
+
+	/*
+	 * Store the DEFAULT, if any, in the catalogs
+	 */
+	if (colDef->raw_default)
+	{
+		RawColumnDefault *rawEnt;
+
+		rawEnt = (RawColumnDefault *) palloc(sizeof(RawColumnDefault));
+		rawEnt->attnum = attribute.attnum;
+		rawEnt->raw_default = copyObject(colDef->raw_default);
+
+		/*
+		 * Attempt to skip a complete table rewrite by storing the specified
+		 * DEFAULT value outside of the heap.  This may be disabled inside
+		 * AddRelationNewConstraints if the optimization cannot be applied.
+		 */
+		rawEnt->missingMode = (!colDef->generated);
+
+		rawEnt->generated = colDef->generated;
+
+		/*
+		 * This function is intended for CREATE TABLE, so it processes a
+		 * _list_ of defaults, but we just do one.
+		 */
+		AddRelationNewConstraints(rel, list_make1(rawEnt), NIL,
+								  false, true, false, NULL);
+
+		/* Make the additional catalog changes visible */
+		CommandCounterIncrement();
+
+		/*
+		 * Did the request for a missing value work? If not we'll have to do a
+		 * rewrite
+		 */
+		if (!rawEnt->missingMode)
+			tab->rewrite |= AT_REWRITE_DEFAULT_VAL;
+	}
+
+	/*
+	 * Tell Phase 3 to fill in the default expression, if there is one.
+	 *
+	 * If there is no default, Phase 3 doesn't have to do anything, because
+	 * that effectively means that the default is NULL.  The heap tuple access
+	 * routines always check for attnum > # of attributes in tuple, and return
+	 * NULL if so, so without any modification of the tuple data we will get
+	 * the effect of NULL values in the new column.
+	 *
+	 * An exception occurs when the new column is of a domain type: the domain
+	 * might have a NOT NULL constraint, or a check constraint that indirectly
+	 * rejects nulls.  If there are any domain constraints then we construct
+	 * an explicit NULL default value that will be passed through
+	 * CoerceToDomain processing.  (This is a tad inefficient, since it causes
+	 * rewriting the table which we really don't have to do, but the present
+	 * design of domain processing doesn't offer any simple way of checking
+	 * the constraints more directly.)
+	 *
+	 * Note: we use build_column_default, and not just the cooked default
+	 * returned by AddRelationNewConstraints, so that the right thing happens
+	 * when a datatype's default applies.
+	 *
+	 * Note: it might seem that this should happen at the end of Phase 2, so
+	 * that the effects of subsequent subcommands can be taken into account.
+	 * It's intentional that we do it now, though.  The new column should be
+	 * filled according to what is said in the ADD COLUMN subcommand, so that
+	 * the effects are the same as if this subcommand had been run by itself
+	 * and the later subcommands had been issued in new ALTER TABLE commands.
+	 *
+	 * We can skip this entirely for relations without storage, since Phase 3
+	 * is certainly not going to touch them.  System attributes don't have
+	 * interesting defaults, either.
+	 */
+	if (RELKIND_HAS_STORAGE(relkind) && attribute.attnum > 0)
+	{
+		/*
+		 * For an identity column, we can't use build_column_default(),
+		 * because the sequence ownership isn't set yet.  So do it manually.
+		 */
+		if (colDef->identity)
+		{
+			NextValueExpr *nve = makeNode(NextValueExpr);
+
+			nve->seqid = RangeVarGetRelid(colDef->identitySequence, NoLock, false);
+			nve->typeId = typeOid;
+
+			defval = (Expr *) nve;
+
+			/* must do a rewrite for identity columns */
+			tab->rewrite |= AT_REWRITE_DEFAULT_VAL;
+		}
+		else
+			defval = (Expr *) build_column_default(rel, attribute.attnum);
+
+		if (!defval && DomainHasConstraints(typeOid))
+		{
+			Oid			baseTypeId;
+			int32		baseTypeMod;
+			Oid			baseTypeColl;
+
+			baseTypeMod = typmod;
+			baseTypeId = getBaseTypeAndTypmod(typeOid, &baseTypeMod);
+			baseTypeColl = get_typcollation(baseTypeId);
+			defval = (Expr *) makeNullConst(baseTypeId, baseTypeMod, baseTypeColl);
+			defval = (Expr *) coerce_to_target_type(NULL,
+													(Node *) defval,
+													baseTypeId,
+													typeOid,
+													typmod,
+													COERCION_ASSIGNMENT,
+													COERCE_IMPLICIT_CAST,
+													-1);
+			if (defval == NULL) /* should not happen */
+				elog(ERROR, "failed to coerce base type to domain");
+		}
+
+		if (defval)
+		{
+			NewColumnValue *newval;
+
+			newval = (NewColumnValue *) palloc0(sizeof(NewColumnValue));
+			newval->attnum = attribute.attnum;
+			newval->expr = expression_planner(defval);
+			newval->is_generated = (colDef->generated != '\0');
+
+			tab->newvals = lappend(tab->newvals, newval);
+		}
+
+		if (DomainHasConstraints(typeOid))
+			tab->rewrite |= AT_REWRITE_DEFAULT_VAL;
+
+		if (!TupleDescAttr(rel->rd_att, attribute.attnum - 1)->atthasmissing)
+		{
+			/*
+			 * If the new column is NOT NULL, and there is no missing value,
+			 * tell Phase 3 it needs to check for NULLs.
+			 */
+			tab->verify_new_notnull |= colDef->is_not_null;
+		}
+	}
+
+	/*
+	 * Add needed dependency entries for the new column.
+	 */
+	add_column_datatype_dependency(myrelid, newattnum, attribute.atttypid);
+	add_column_collation_dependency(myrelid, newattnum, attribute.attcollation);
+
+	/*
+	 * Propagate to children as appropriate.  Unlike most other ALTER
+	 * routines, we have to do this one level of recursion at a time; we can't
+	 * use find_all_inheritors to do it in one pass.
+	 */
+	children =
+		find_inheritance_children(RelationGetRelid(rel), lockmode);
+
+	/*
+	 * If we are told not to recurse, there had better not be any child
+	 * tables; else the addition would put them out of step.
+	 */
+	if (children && !recurse)
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
+				 errmsg("column must be added to child tables too")));
+
+	/* Children should see column as singly inherited */
+	if (!recursing)
+	{
+		childcmd = copyObject(*cmd);
+		colDef = castNode(ColumnDef, childcmd->def);
+		colDef->inhcount = 1;
+		colDef->is_local = false;
+	}
+	else
+		childcmd = *cmd;		/* no need to copy again */
+
+	foreach(child, children)
+	{
+		Oid			childrelid = lfirst_oid(child);
+		Relation	childrel;
+		AlteredTableInfo *childtab;
+
+		/* find_inheritance_children already got lock */
+		childrel = table_open(childrelid, NoLock);
+		CheckTableNotInUse(childrel, "ALTER TABLE");
+
+		/* Find or create work queue entry for this table */
+		childtab = ATGetQueueEntry(wqueue, childrel);
+
+		/* Recurse to child; return value is ignored */
+		ATExecAddColumn(wqueue, childtab, childrel,
+						&childcmd, recurse, true,
+						lockmode, cur_pass, context);
+
+		table_close(childrel, NoLock);
+	}
+
+	ObjectAddressSubSet(address, RelationRelationId, myrelid, newattnum);
+	return address;
+}
+
+/*
+ * If a new or renamed column will collide with the name of an existing
+ * column and if_not_exists is false then error out, else do nothing.
+ */
+static bool
+check_for_column_name_collision(Relation rel, const char *colname,
+								bool if_not_exists)
+{
+	HeapTuple	attTuple;
+	int			attnum;
+
+	/*
+	 * this test is deliberately not attisdropped-aware, since if one tries to
+	 * add a column matching a dropped column name, it's gonna fail anyway.
+	 */
+	attTuple = SearchSysCache2(ATTNAME,
+							   ObjectIdGetDatum(RelationGetRelid(rel)),
+							   PointerGetDatum(colname));
+	if (!HeapTupleIsValid(attTuple))
+		return true;
+
+	attnum = ((Form_pg_attribute) GETSTRUCT(attTuple))->attnum;
+	ReleaseSysCache(attTuple);
+
+	/*
+	 * We throw a different error message for conflicts with system column
+	 * names, since they are normally not shown and the user might otherwise
+	 * be confused about the reason for the conflict.
+	 */
+	if (attnum <= 0)
+		ereport(ERROR,
+				(errcode(ERRCODE_DUPLICATE_COLUMN),
+				 errmsg("column name \"%s\" conflicts with a system column name",
+						colname)));
+	else
+	{
+		if (if_not_exists)
+		{
+			ereport(NOTICE,
+					(errcode(ERRCODE_DUPLICATE_COLUMN),
+					 errmsg("column \"%s\" of relation \"%s\" already exists, skipping",
+							colname, RelationGetRelationName(rel))));
+			return false;
+		}
+
+		ereport(ERROR,
+				(errcode(ERRCODE_DUPLICATE_COLUMN),
+				 errmsg("column \"%s\" of relation \"%s\" already exists",
+						colname, RelationGetRelationName(rel))));
+	}
+
+	return true;
+}
+
+/*
+ * Install a column's dependency on its datatype.
+ */
+static void
+add_column_datatype_dependency(Oid relid, int32 attnum, Oid typid)
+{
+	ObjectAddress myself,
+				referenced;
+
+	myself.classId = RelationRelationId;
+	myself.objectId = relid;
+	myself.objectSubId = attnum;
+	referenced.classId = TypeRelationId;
+	referenced.objectId = typid;
+	referenced.objectSubId = 0;
+	recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
+}
+
+/*
+ * Install a column's dependency on its collation.
+ */
+static void
+add_column_collation_dependency(Oid relid, int32 attnum, Oid collid)
+{
+	ObjectAddress myself,
+				referenced;
+
+	/* We know the default collation is pinned, so don't bother recording it */
+	if (OidIsValid(collid) && collid != DEFAULT_COLLATION_OID)
+	{
+		myself.classId = RelationRelationId;
+		myself.objectId = relid;
+		myself.objectSubId = attnum;
+		referenced.classId = CollationRelationId;
+		referenced.objectId = collid;
+		referenced.objectSubId = 0;
+		recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
+	}
+}
+
+/*
+ * ALTER TABLE ALTER COLUMN DROP NOT NULL
+ */
+
+static void
+ATPrepDropNotNull(Relation rel, bool recurse, bool recursing)
+{
+	/*
+	 * If the parent is a partitioned table, like check constraints, we do not
+	 * support removing the NOT NULL while partitions exist.
+	 */
+	if (rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
+	{
+		PartitionDesc partdesc = RelationGetPartitionDesc(rel, true);
+
+		Assert(partdesc != NULL);
+		if (partdesc->nparts > 0 && !recurse && !recursing)
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
+					 errmsg("cannot remove constraint from only the partitioned table when partitions exist"),
+					 errhint("Do not specify the ONLY keyword.")));
+	}
+}
+
+/*
+ * Return the address of the modified column.  If the column was already
+ * nullable, InvalidObjectAddress is returned.
+ */
+static ObjectAddress
+ATExecDropNotNull(Relation rel, const char *colName, LOCKMODE lockmode)
+{
+	HeapTuple	tuple;
+	Form_pg_attribute attTup;
+	AttrNumber	attnum;
+	Relation	attr_rel;
+	List	   *indexoidlist;
+	ListCell   *indexoidscan;
+	ObjectAddress address;
+
+	/*
+	 * lookup the attribute
+	 */
+	attr_rel = table_open(AttributeRelationId, RowExclusiveLock);
+
+	tuple = SearchSysCacheCopyAttName(RelationGetRelid(rel), colName);
+	if (!HeapTupleIsValid(tuple))
+		ereport(ERROR,
+				(errcode(ERRCODE_UNDEFINED_COLUMN),
+				 errmsg("column \"%s\" of relation \"%s\" does not exist",
+						colName, RelationGetRelationName(rel))));
+	attTup = (Form_pg_attribute) GETSTRUCT(tuple);
+	attnum = attTup->attnum;
+
+	/* Prevent them from altering a system attribute */
+	if (attnum <= 0)
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("cannot alter system column \"%s\"",
+						colName)));
+
+	if (attTup->attidentity)
+		ereport(ERROR,
+				(errcode(ERRCODE_SYNTAX_ERROR),
+				 errmsg("column \"%s\" of relation \"%s\" is an identity column",
+						colName, RelationGetRelationName(rel))));
+
+	/*
+	 * Check that the attribute is not in a primary key or in an index used as
+	 * a replica identity.
+	 *
+	 * Note: we'll throw error even if the pkey index is not valid.
+	 */
+
+	/* Loop over all indexes on the relation */
+	indexoidlist = RelationGetIndexList(rel);
+
+	foreach(indexoidscan, indexoidlist)
+	{
+		Oid			indexoid = lfirst_oid(indexoidscan);
+		HeapTuple	indexTuple;
+		Form_pg_index indexStruct;
+		int			i;
+
+		indexTuple = SearchSysCache1(INDEXRELID, ObjectIdGetDatum(indexoid));
+		if (!HeapTupleIsValid(indexTuple))
+			elog(ERROR, "cache lookup failed for index %u", indexoid);
+		indexStruct = (Form_pg_index) GETSTRUCT(indexTuple);
+
+		/*
+		 * If the index is not a primary key or an index used as replica
+		 * identity, skip the check.
+		 */
+		if (indexStruct->indisprimary || indexStruct->indisreplident)
+		{
+			/*
+			 * Loop over each attribute in the primary key or the index used
+			 * as replica identity and see if it matches the to-be-altered
+			 * attribute.
+			 */
+			for (i = 0; i < indexStruct->indnkeyatts; i++)
+			{
+				if (indexStruct->indkey.values[i] == attnum)
+				{
+					if (indexStruct->indisprimary)
+						ereport(ERROR,
+								(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
+								 errmsg("column \"%s\" is in a primary key",
+										colName)));
+					else
+						ereport(ERROR,
+								(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
+								 errmsg("column \"%s\" is in index used as replica identity",
+										colName)));
+				}
+			}
+		}
+
+		ReleaseSysCache(indexTuple);
+	}
+
+	list_free(indexoidlist);
+
+	/* If rel is partition, shouldn't drop NOT NULL if parent has the same */
+	if (rel->rd_rel->relispartition)
+	{
+		Oid			parentId = get_partition_parent(RelationGetRelid(rel), false);
+		Relation	parent = table_open(parentId, AccessShareLock);
+		TupleDesc	tupDesc = RelationGetDescr(parent);
+		AttrNumber	parent_attnum;
+
+		parent_attnum = get_attnum(parentId, colName);
+		if (TupleDescAttr(tupDesc, parent_attnum - 1)->attnotnull)
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
+					 errmsg("column \"%s\" is marked NOT NULL in parent table",
+							colName)));
+		table_close(parent, AccessShareLock);
+	}
+
+	/*
+	 * Okay, actually perform the catalog change ... if needed
+	 */
+	if (attTup->attnotnull)
+	{
+		attTup->attnotnull = false;
+
+		CatalogTupleUpdate(attr_rel, &tuple->t_self, tuple);
+
+		ObjectAddressSubSet(address, RelationRelationId,
+							RelationGetRelid(rel), attnum);
+	}
+	else
+		address = InvalidObjectAddress;
+
+	InvokeObjectPostAlterHook(RelationRelationId,
+							  RelationGetRelid(rel), attnum);
+
+	table_close(attr_rel, RowExclusiveLock);
+
+	return address;
+}
+
+/*
+ * ALTER TABLE ALTER COLUMN SET NOT NULL
+ */
+
+static void
+ATPrepSetNotNull(List **wqueue, Relation rel,
+				 AlterTableCmd *cmd, bool recurse, bool recursing,
+				 LOCKMODE lockmode, AlterTableUtilityContext *context)
+{
+	/*
+	 * If we're already recursing, there's nothing to do; the topmost
+	 * invocation of ATSimpleRecursion already visited all children.
+	 */
+	if (recursing)
+		return;
+
+	/*
+	 * If the target column is already marked NOT NULL, we can skip recursing
+	 * to children, because their columns should already be marked NOT NULL as
+	 * well.  But there's no point in checking here unless the relation has
+	 * some children; else we can just wait till execution to check.  (If it
+	 * does have children, however, this can save taking per-child locks
+	 * unnecessarily.  This greatly improves concurrency in some parallel
+	 * restore scenarios.)
+	 *
+	 * Unfortunately, we can only apply this optimization to partitioned
+	 * tables, because traditional inheritance doesn't enforce that child
+	 * columns be NOT NULL when their parent is.  (That's a bug that should
+	 * get fixed someday.)
+	 */
+	if (rel->rd_rel->relhassubclass &&
+		rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
+	{
+		HeapTuple	tuple;
+		bool		attnotnull;
+
+		tuple = SearchSysCacheAttName(RelationGetRelid(rel), cmd->name);
+
+		/* Might as well throw the error now, if name is bad */
+		if (!HeapTupleIsValid(tuple))
+			ereport(ERROR,
+					(errcode(ERRCODE_UNDEFINED_COLUMN),
+					 errmsg("column \"%s\" of relation \"%s\" does not exist",
+							cmd->name, RelationGetRelationName(rel))));
+
+		attnotnull = ((Form_pg_attribute) GETSTRUCT(tuple))->attnotnull;
+		ReleaseSysCache(tuple);
+		if (attnotnull)
+			return;
+	}
+
+	/*
+	 * If we have ALTER TABLE ONLY ... SET NOT NULL on a partitioned table,
+	 * apply ALTER TABLE ... CHECK NOT NULL to every child.  Otherwise, use
+	 * normal recursion logic.
+	 */
+	if (rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE &&
+		!recurse)
+	{
+		AlterTableCmd *newcmd = makeNode(AlterTableCmd);
+
+		newcmd->subtype = AT_CheckNotNull;
+		newcmd->name = pstrdup(cmd->name);
+		ATSimpleRecursion(wqueue, rel, newcmd, true, lockmode, context);
+	}
+	else
+		ATSimpleRecursion(wqueue, rel, cmd, recurse, lockmode, context);
+}
+
+/*
+ * Return the address of the modified column.  If the column was already NOT
+ * NULL, InvalidObjectAddress is returned.
+ */
+static ObjectAddress
+ATExecSetNotNull(AlteredTableInfo *tab, Relation rel,
+				 const char *colName, LOCKMODE lockmode)
+{
+	HeapTuple	tuple;
+	AttrNumber	attnum;
+	Relation	attr_rel;
+	ObjectAddress address;
+
+	/*
+	 * lookup the attribute
+	 */
+	attr_rel = table_open(AttributeRelationId, RowExclusiveLock);
+
+	tuple = SearchSysCacheCopyAttName(RelationGetRelid(rel), colName);
+
+	if (!HeapTupleIsValid(tuple))
+		ereport(ERROR,
+				(errcode(ERRCODE_UNDEFINED_COLUMN),
+				 errmsg("column \"%s\" of relation \"%s\" does not exist",
+						colName, RelationGetRelationName(rel))));
+
+	attnum = ((Form_pg_attribute) GETSTRUCT(tuple))->attnum;
+
+	/* Prevent them from altering a system attribute */
+	if (attnum <= 0)
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("cannot alter system column \"%s\"",
+						colName)));
+
+	/*
+	 * Okay, actually perform the catalog change ... if needed
+	 */
+	if (!((Form_pg_attribute) GETSTRUCT(tuple))->attnotnull)
+	{
+		((Form_pg_attribute) GETSTRUCT(tuple))->attnotnull = true;
+
+		CatalogTupleUpdate(attr_rel, &tuple->t_self, tuple);
+
+		/*
+		 * Ordinarily phase 3 must ensure that no NULLs exist in columns that
+		 * are set NOT NULL; however, if we can find a constraint which proves
+		 * this then we can skip that.  We needn't bother looking if we've
+		 * already found that we must verify some other NOT NULL constraint.
+		 */
+		if (!tab->verify_new_notnull &&
+			!NotNullImpliedByRelConstraints(rel, (Form_pg_attribute) GETSTRUCT(tuple)))
+		{
+			/* Tell Phase 3 it needs to test the constraint */
+			tab->verify_new_notnull = true;
+		}
+
+		ObjectAddressSubSet(address, RelationRelationId,
+							RelationGetRelid(rel), attnum);
+	}
+	else
+		address = InvalidObjectAddress;
+
+	InvokeObjectPostAlterHook(RelationRelationId,
+							  RelationGetRelid(rel), attnum);
+
+	table_close(attr_rel, RowExclusiveLock);
+
+	return address;
+}
+
+/*
+ * ALTER TABLE ALTER COLUMN CHECK NOT NULL
+ *
+ * This doesn't exist in the grammar, but we generate AT_CheckNotNull
+ * commands against the partitions of a partitioned table if the user
+ * writes ALTER TABLE ONLY ... SET NOT NULL on the partitioned table,
+ * or tries to create a primary key on it (which internally creates
+ * AT_SetNotNull on the partitioned table).   Such a command doesn't
+ * allow us to actually modify any partition, but we want to let it
+ * go through if the partitions are already properly marked.
+ *
+ * In future, this might need to adjust the child table's state, likely
+ * by incrementing an inheritance count for the attnotnull constraint.
+ * For now we need only check for the presence of the flag.
+ */
+static void
+ATExecCheckNotNull(AlteredTableInfo *tab, Relation rel,
+				   const char *colName, LOCKMODE lockmode)
+{
+	HeapTuple	tuple;
+
+	tuple = SearchSysCacheAttName(RelationGetRelid(rel), colName);
+
+	if (!HeapTupleIsValid(tuple))
+		ereport(ERROR,
+				(errcode(ERRCODE_UNDEFINED_COLUMN),
+				 errmsg("column \"%s\" of relation \"%s\" does not exist",
+						colName, RelationGetRelationName(rel))));
+
+	if (!((Form_pg_attribute) GETSTRUCT(tuple))->attnotnull)
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
+				 errmsg("constraint must be added to child tables too"),
+				 errdetail("Column \"%s\" of relation \"%s\" is not already NOT NULL.",
+						   colName, RelationGetRelationName(rel)),
+				 errhint("Do not specify the ONLY keyword.")));
+
+	ReleaseSysCache(tuple);
+}
+
+/*
+ * NotNullImpliedByRelConstraints
+ *		Does rel's existing constraints imply NOT NULL for the given attribute?
+ */
+static bool
+NotNullImpliedByRelConstraints(Relation rel, Form_pg_attribute attr)
+{
+	NullTest   *nnulltest = makeNode(NullTest);
+
+	nnulltest->arg = (Expr *) makeVar(1,
+									  attr->attnum,
+									  attr->atttypid,
+									  attr->atttypmod,
+									  attr->attcollation,
+									  0);
+	nnulltest->nulltesttype = IS_NOT_NULL;
+
+	/*
+	 * argisrow = false is correct even for a composite column, because
+	 * attnotnull does not represent a SQL-spec IS NOT NULL test in such a
+	 * case, just IS DISTINCT FROM NULL.
+	 */
+	nnulltest->argisrow = false;
+	nnulltest->location = -1;
+
+	if (ConstraintImpliedByRelConstraint(rel, list_make1(nnulltest), NIL))
+	{
+		ereport(DEBUG1,
+				(errmsg_internal("existing constraints on column \"%s.%s\" are sufficient to prove that it does not contain nulls",
+								 RelationGetRelationName(rel), NameStr(attr->attname))));
+		return true;
+	}
+
+	return false;
+}
+
+/*
+ * ALTER TABLE ALTER COLUMN SET/DROP DEFAULT
+ *
+ * Return the address of the affected column.
+ */
+static ObjectAddress
+ATExecColumnDefault(Relation rel, const char *colName,
+					Node *newDefault, LOCKMODE lockmode)
+{
+	TupleDesc	tupdesc = RelationGetDescr(rel);
+	AttrNumber	attnum;
+	ObjectAddress address;
+
+	/*
+	 * get the number of the attribute
+	 */
+	attnum = get_attnum(RelationGetRelid(rel), colName);
+	if (attnum == InvalidAttrNumber)
+		ereport(ERROR,
+				(errcode(ERRCODE_UNDEFINED_COLUMN),
+				 errmsg("column \"%s\" of relation \"%s\" does not exist",
+						colName, RelationGetRelationName(rel))));
+
+	/* Prevent them from altering a system attribute */
+	if (attnum <= 0)
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("cannot alter system column \"%s\"",
+						colName)));
+
+	if (TupleDescAttr(tupdesc, attnum - 1)->attidentity)
+		ereport(ERROR,
+				(errcode(ERRCODE_SYNTAX_ERROR),
+				 errmsg("column \"%s\" of relation \"%s\" is an identity column",
+						colName, RelationGetRelationName(rel)),
+				 newDefault ? 0 : errhint("Use ALTER TABLE ... ALTER COLUMN ... DROP IDENTITY instead.")));
+
+	if (TupleDescAttr(tupdesc, attnum - 1)->attgenerated)
+		ereport(ERROR,
+				(errcode(ERRCODE_SYNTAX_ERROR),
+				 errmsg("column \"%s\" of relation \"%s\" is a generated column",
+						colName, RelationGetRelationName(rel)),
+				 newDefault || TupleDescAttr(tupdesc, attnum - 1)->attgenerated != ATTRIBUTE_GENERATED_STORED ? 0 :
+				 errhint("Use ALTER TABLE ... ALTER COLUMN ... DROP EXPRESSION instead.")));
+
+	/*
+	 * Remove any old default for the column.  We use RESTRICT here for
+	 * safety, but at present we do not expect anything to depend on the
+	 * default.
+	 *
+	 * We treat removing the existing default as an internal operation when it
+	 * is preparatory to adding a new default, but as a user-initiated
+	 * operation when the user asked for a drop.
+	 */
+	RemoveAttrDefault(RelationGetRelid(rel), attnum, DROP_RESTRICT, false,
+					  newDefault != NULL);
+
+	if (newDefault)
+	{
+		/* SET DEFAULT */
+		RawColumnDefault *rawEnt;
+
+		rawEnt = (RawColumnDefault *) palloc(sizeof(RawColumnDefault));
+		rawEnt->attnum = attnum;
+		rawEnt->raw_default = newDefault;
+		rawEnt->missingMode = false;
+		rawEnt->generated = '\0';
+
+		/*
+		 * This function is intended for CREATE TABLE, so it processes a
+		 * _list_ of defaults, but we just do one.
+		 */
+		AddRelationNewConstraints(rel, list_make1(rawEnt), NIL,
+								  false, true, false, NULL);
+	}
+
+	ObjectAddressSubSet(address, RelationRelationId,
+						RelationGetRelid(rel), attnum);
+	return address;
+}
+
+/*
+ * Add a pre-cooked default expression.
+ *
+ * Return the address of the affected column.
+ */
+static ObjectAddress
+ATExecCookedColumnDefault(Relation rel, AttrNumber attnum,
+						  Node *newDefault)
+{
+	ObjectAddress address;
+
+	/* We assume no checking is required */
+
+	/*
+	 * Remove any old default for the column.  We use RESTRICT here for
+	 * safety, but at present we do not expect anything to depend on the
+	 * default.  (In ordinary cases, there could not be a default in place
+	 * anyway, but it's possible when combining LIKE with inheritance.)
+	 */
+	RemoveAttrDefault(RelationGetRelid(rel), attnum, DROP_RESTRICT, false,
+					  true);
+
+	(void) StoreAttrDefault(rel, attnum, newDefault, true, false);
+
+	ObjectAddressSubSet(address, RelationRelationId,
+						RelationGetRelid(rel), attnum);
+	return address;
+}
+
+/*
+ * ALTER TABLE ALTER COLUMN ADD IDENTITY
+ *
+ * Return the address of the affected column.
+ */
+static ObjectAddress
+ATExecAddIdentity(Relation rel, const char *colName,
+				  Node *def, LOCKMODE lockmode)
+{
+	Relation	attrelation;
+	HeapTuple	tuple;
+	Form_pg_attribute attTup;
+	AttrNumber	attnum;
+	ObjectAddress address;
+	ColumnDef  *cdef = castNode(ColumnDef, def);
+
+	attrelation = table_open(AttributeRelationId, RowExclusiveLock);
+
+	tuple = SearchSysCacheCopyAttName(RelationGetRelid(rel), colName);
+	if (!HeapTupleIsValid(tuple))
+		ereport(ERROR,
+				(errcode(ERRCODE_UNDEFINED_COLUMN),
+				 errmsg("column \"%s\" of relation \"%s\" does not exist",
+						colName, RelationGetRelationName(rel))));
+	attTup = (Form_pg_attribute) GETSTRUCT(tuple);
+	attnum = attTup->attnum;
+
+	/* Can't alter a system attribute */
+	if (attnum <= 0)
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("cannot alter system column \"%s\"",
+						colName)));
+
+	/*
+	 * Creating a column as identity implies NOT NULL, so adding the identity
+	 * to an existing column that is not NOT NULL would create a state that
+	 * cannot be reproduced without contortions.
+	 */
+	if (!attTup->attnotnull)
+		ereport(ERROR,
+				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+				 errmsg("column \"%s\" of relation \"%s\" must be declared NOT NULL before identity can be added",
+						colName, RelationGetRelationName(rel))));
+
+	if (attTup->attidentity)
+		ereport(ERROR,
+				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+				 errmsg("column \"%s\" of relation \"%s\" is already an identity column",
+						colName, RelationGetRelationName(rel))));
+
+	if (attTup->atthasdef)
+		ereport(ERROR,
+				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+				 errmsg("column \"%s\" of relation \"%s\" already has a default value",
+						colName, RelationGetRelationName(rel))));
+
+	attTup->attidentity = cdef->identity;
+	CatalogTupleUpdate(attrelation, &tuple->t_self, tuple);
+
+	InvokeObjectPostAlterHook(RelationRelationId,
+							  RelationGetRelid(rel),
+							  attTup->attnum);
+	ObjectAddressSubSet(address, RelationRelationId,
+						RelationGetRelid(rel), attnum);
+	heap_freetuple(tuple);
+
+	table_close(attrelation, RowExclusiveLock);
+
+	return address;
+}
+
+/*
+ * ALTER TABLE ALTER COLUMN SET { GENERATED or sequence options }
+ *
+ * Return the address of the affected column.
+ */
+static ObjectAddress
+ATExecSetIdentity(Relation rel, const char *colName, Node *def, LOCKMODE lockmode)
+{
+	ListCell   *option;
+	DefElem    *generatedEl = NULL;
+	HeapTuple	tuple;
+	Form_pg_attribute attTup;
+	AttrNumber	attnum;
+	Relation	attrelation;
+	ObjectAddress address;
+
+	foreach(option, castNode(List, def))
+	{
+		DefElem    *defel = lfirst_node(DefElem, option);
+
+		if (strcmp(defel->defname, "generated") == 0)
+		{
+			if (generatedEl)
+				ereport(ERROR,
+						(errcode(ERRCODE_SYNTAX_ERROR),
+						 errmsg("conflicting or redundant options")));
+			generatedEl = defel;
+		}
+		else
+			elog(ERROR, "option \"%s\" not recognized",
+				 defel->defname);
+	}
+
+	/*
+	 * Even if there is nothing to change here, we run all the checks.  There
+	 * will be a subsequent ALTER SEQUENCE that relies on everything being
+	 * there.
+	 */
+
+	attrelation = table_open(AttributeRelationId, RowExclusiveLock);
+	tuple = SearchSysCacheCopyAttName(RelationGetRelid(rel), colName);
+	if (!HeapTupleIsValid(tuple))
+		ereport(ERROR,
+				(errcode(ERRCODE_UNDEFINED_COLUMN),
+				 errmsg("column \"%s\" of relation \"%s\" does not exist",
+						colName, RelationGetRelationName(rel))));
+
+	attTup = (Form_pg_attribute) GETSTRUCT(tuple);
+	attnum = attTup->attnum;
+
+	if (attnum <= 0)
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("cannot alter system column \"%s\"",
+						colName)));
+
+	if (!attTup->attidentity)
+		ereport(ERROR,
+				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+				 errmsg("column \"%s\" of relation \"%s\" is not an identity column",
+						colName, RelationGetRelationName(rel))));
+
+	if (generatedEl)
+	{
+		attTup->attidentity = defGetInt32(generatedEl);
+		CatalogTupleUpdate(attrelation, &tuple->t_self, tuple);
+
+		InvokeObjectPostAlterHook(RelationRelationId,
+								  RelationGetRelid(rel),
+								  attTup->attnum);
+		ObjectAddressSubSet(address, RelationRelationId,
+							RelationGetRelid(rel), attnum);
+	}
+	else
+		address = InvalidObjectAddress;
+
+	heap_freetuple(tuple);
+	table_close(attrelation, RowExclusiveLock);
+
+	return address;
+}
+
+/*
+ * ALTER TABLE ALTER COLUMN DROP IDENTITY
+ *
+ * Return the address of the affected column.
+ */
+static ObjectAddress
+ATExecDropIdentity(Relation rel, const char *colName, bool missing_ok, LOCKMODE lockmode)
+{
+	HeapTuple	tuple;
+	Form_pg_attribute attTup;
+	AttrNumber	attnum;
+	Relation	attrelation;
+	ObjectAddress address;
+	Oid			seqid;
+	ObjectAddress seqaddress;
+
+	attrelation = table_open(AttributeRelationId, RowExclusiveLock);
+	tuple = SearchSysCacheCopyAttName(RelationGetRelid(rel), colName);
+	if (!HeapTupleIsValid(tuple))
+		ereport(ERROR,
+				(errcode(ERRCODE_UNDEFINED_COLUMN),
+				 errmsg("column \"%s\" of relation \"%s\" does not exist",
+						colName, RelationGetRelationName(rel))));
+
+	attTup = (Form_pg_attribute) GETSTRUCT(tuple);
+	attnum = attTup->attnum;
+
+	if (attnum <= 0)
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("cannot alter system column \"%s\"",
+						colName)));
+
+	if (!attTup->attidentity)
+	{
+		if (!missing_ok)
+			ereport(ERROR,
+					(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+					 errmsg("column \"%s\" of relation \"%s\" is not an identity column",
+							colName, RelationGetRelationName(rel))));
+		else
+		{
+			ereport(NOTICE,
+					(errmsg("column \"%s\" of relation \"%s\" is not an identity column, skipping",
+							colName, RelationGetRelationName(rel))));
+			heap_freetuple(tuple);
+			table_close(attrelation, RowExclusiveLock);
+			return InvalidObjectAddress;
+		}
+	}
+
+	attTup->attidentity = '\0';
+	CatalogTupleUpdate(attrelation, &tuple->t_self, tuple);
+
+	InvokeObjectPostAlterHook(RelationRelationId,
+							  RelationGetRelid(rel),
+							  attTup->attnum);
+	ObjectAddressSubSet(address, RelationRelationId,
+						RelationGetRelid(rel), attnum);
+	heap_freetuple(tuple);
+
+	table_close(attrelation, RowExclusiveLock);
+
+	/* drop the internal sequence */
+	seqid = getIdentitySequence(RelationGetRelid(rel), attnum, false);
+	deleteDependencyRecordsForClass(RelationRelationId, seqid,
+									RelationRelationId, DEPENDENCY_INTERNAL);
+	CommandCounterIncrement();
+	seqaddress.classId = RelationRelationId;
+	seqaddress.objectId = seqid;
+	seqaddress.objectSubId = 0;
+	performDeletion(&seqaddress, DROP_RESTRICT, PERFORM_DELETION_INTERNAL);
+
+	return address;
+}
+
+/*
+ * ALTER TABLE ALTER COLUMN DROP EXPRESSION
+ */
+static void
+ATPrepDropExpression(Relation rel, AlterTableCmd *cmd, bool recurse, bool recursing, LOCKMODE lockmode)
+{
+	/*
+	 * Reject ONLY if there are child tables.  We could implement this, but it
+	 * is a bit complicated.  GENERATED clauses must be attached to the column
+	 * definition and cannot be added later like DEFAULT, so if a child table
+	 * has a generation expression that the parent does not have, the child
+	 * column will necessarily be an attlocal column.  So to implement ONLY
+	 * here, we'd need extra code to update attislocal of the direct child
+	 * tables, somewhat similar to how DROP COLUMN does it, so that the
+	 * resulting state can be properly dumped and restored.
+	 */
+	if (!recurse &&
+		find_inheritance_children(RelationGetRelid(rel), lockmode))
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("ALTER TABLE / DROP EXPRESSION must be applied to child tables too")));
+
+	/*
+	 * Cannot drop generation expression from inherited columns.
+	 */
+	if (!recursing)
+	{
+		HeapTuple	tuple;
+		Form_pg_attribute attTup;
+
+		tuple = SearchSysCacheCopyAttName(RelationGetRelid(rel), cmd->name);
+		if (!HeapTupleIsValid(tuple))
+			ereport(ERROR,
+					(errcode(ERRCODE_UNDEFINED_COLUMN),
+					 errmsg("column \"%s\" of relation \"%s\" does not exist",
+							cmd->name, RelationGetRelationName(rel))));
+
+		attTup = (Form_pg_attribute) GETSTRUCT(tuple);
+
+		if (attTup->attinhcount > 0)
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
+					 errmsg("cannot drop generation expression from inherited column")));
+	}
+}
+
+/*
+ * Return the address of the affected column.
+ */
+static ObjectAddress
+ATExecDropExpression(Relation rel, const char *colName, bool missing_ok, LOCKMODE lockmode)
+{
+	HeapTuple	tuple;
+	Form_pg_attribute attTup;
+	AttrNumber	attnum;
+	Relation	attrelation;
+	Oid			attrdefoid;
+	ObjectAddress address;
+
+	attrelation = table_open(AttributeRelationId, RowExclusiveLock);
+	tuple = SearchSysCacheCopyAttName(RelationGetRelid(rel), colName);
+	if (!HeapTupleIsValid(tuple))
+		ereport(ERROR,
+				(errcode(ERRCODE_UNDEFINED_COLUMN),
+				 errmsg("column \"%s\" of relation \"%s\" does not exist",
+						colName, RelationGetRelationName(rel))));
+
+	attTup = (Form_pg_attribute) GETSTRUCT(tuple);
+	attnum = attTup->attnum;
+
+	if (attnum <= 0)
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("cannot alter system column \"%s\"",
+						colName)));
+
+	if (attTup->attgenerated != ATTRIBUTE_GENERATED_STORED)
+	{
+		if (!missing_ok)
+			ereport(ERROR,
+					(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+					 errmsg("column \"%s\" of relation \"%s\" is not a stored generated column",
+							colName, RelationGetRelationName(rel))));
+		else
+		{
+			ereport(NOTICE,
+					(errmsg("column \"%s\" of relation \"%s\" is not a stored generated column, skipping",
+							colName, RelationGetRelationName(rel))));
+			heap_freetuple(tuple);
+			table_close(attrelation, RowExclusiveLock);
+			return InvalidObjectAddress;
+		}
+	}
+
+	/*
+	 * Mark the column as no longer generated.  (The atthasdef flag needs to
+	 * get cleared too, but RemoveAttrDefault will handle that.)
+	 */
+	attTup->attgenerated = '\0';
+	CatalogTupleUpdate(attrelation, &tuple->t_self, tuple);
+
+	InvokeObjectPostAlterHook(RelationRelationId,
+							  RelationGetRelid(rel),
+							  attnum);
+	heap_freetuple(tuple);
+
+	table_close(attrelation, RowExclusiveLock);
+
+	/*
+	 * Drop the dependency records of the GENERATED expression, in particular
+	 * its INTERNAL dependency on the column, which would otherwise cause
+	 * dependency.c to refuse to perform the deletion.
+	 */
+	attrdefoid = GetAttrDefaultOid(RelationGetRelid(rel), attnum);
+	if (!OidIsValid(attrdefoid))
+		elog(ERROR, "could not find attrdef tuple for relation %u attnum %d",
+			 RelationGetRelid(rel), attnum);
+	(void) deleteDependencyRecordsFor(AttrDefaultRelationId, attrdefoid, false);
+
+	/* Make above changes visible */
+	CommandCounterIncrement();
+
+	/*
+	 * Get rid of the GENERATED expression itself.  We use RESTRICT here for
+	 * safety, but at present we do not expect anything to depend on the
+	 * default.
+	 */
+	RemoveAttrDefault(RelationGetRelid(rel), attnum, DROP_RESTRICT,
+					  false, false);
+
+	ObjectAddressSubSet(address, RelationRelationId,
+						RelationGetRelid(rel), attnum);
+	return address;
+}
+
+/*
+ * ALTER TABLE ALTER COLUMN SET STATISTICS
+ *
+ * Return value is the address of the modified column
+ */
+static ObjectAddress
+ATExecSetStatistics(Relation rel, const char *colName, int16 colNum, Node *newValue, LOCKMODE lockmode)
+{
+	int			newtarget;
+	Relation	attrelation;
+	HeapTuple	tuple;
+	Form_pg_attribute attrtuple;
+	AttrNumber	attnum;
+	ObjectAddress address;
+
+	/*
+	 * We allow referencing columns by numbers only for indexes, since table
+	 * column numbers could contain gaps if columns are later dropped.
+	 */
+	if (rel->rd_rel->relkind != RELKIND_INDEX &&
+		rel->rd_rel->relkind != RELKIND_PARTITIONED_INDEX &&
+		!colName)
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("cannot refer to non-index column by number")));
+
+	Assert(IsA(newValue, Integer));
+	newtarget = intVal(newValue);
+
+	/*
+	 * Limit target to a sane range
+	 */
+	if (newtarget < -1)
+	{
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("statistics target %d is too low",
+						newtarget)));
+	}
+	else if (newtarget > 10000)
+	{
+		newtarget = 10000;
+		ereport(WARNING,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("lowering statistics target to %d",
+						newtarget)));
+	}
+
+	attrelation = table_open(AttributeRelationId, RowExclusiveLock);
+
+	if (colName)
+	{
+		tuple = SearchSysCacheCopyAttName(RelationGetRelid(rel), colName);
+
+		if (!HeapTupleIsValid(tuple))
+			ereport(ERROR,
+					(errcode(ERRCODE_UNDEFINED_COLUMN),
+					 errmsg("column \"%s\" of relation \"%s\" does not exist",
+							colName, RelationGetRelationName(rel))));
+	}
+	else
+	{
+		tuple = SearchSysCacheCopyAttNum(RelationGetRelid(rel), colNum);
+
+		if (!HeapTupleIsValid(tuple))
+			ereport(ERROR,
+					(errcode(ERRCODE_UNDEFINED_COLUMN),
+					 errmsg("column number %d of relation \"%s\" does not exist",
+							colNum, RelationGetRelationName(rel))));
+	}
+
+	attrtuple = (Form_pg_attribute) GETSTRUCT(tuple);
+
+	attnum = attrtuple->attnum;
+	if (attnum <= 0)
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("cannot alter system column \"%s\"",
+						colName)));
+
+	if (rel->rd_rel->relkind == RELKIND_INDEX ||
+		rel->rd_rel->relkind == RELKIND_PARTITIONED_INDEX)
+	{
+		if (attnum > rel->rd_index->indnkeyatts)
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("cannot alter statistics on included column \"%s\" of index \"%s\"",
+							NameStr(attrtuple->attname), RelationGetRelationName(rel))));
+		else if (rel->rd_index->indkey.values[attnum - 1] != 0)
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("cannot alter statistics on non-expression column \"%s\" of index \"%s\"",
+							NameStr(attrtuple->attname), RelationGetRelationName(rel)),
+					 errhint("Alter statistics on table column instead.")));
+	}
+
+	attrtuple->attstattarget = newtarget;
+
+	CatalogTupleUpdate(attrelation, &tuple->t_self, tuple);
+
+	InvokeObjectPostAlterHook(RelationRelationId,
+							  RelationGetRelid(rel),
+							  attrtuple->attnum);
+	ObjectAddressSubSet(address, RelationRelationId,
+						RelationGetRelid(rel), attnum);
+	heap_freetuple(tuple);
+
+	table_close(attrelation, RowExclusiveLock);
+
+	return address;
+}
+
+/*
+ * Return value is the address of the modified column
+ */
+static ObjectAddress
+ATExecSetOptions(Relation rel, const char *colName, Node *options,
+				 bool isReset, LOCKMODE lockmode)
+{
+	Relation	attrelation;
+	HeapTuple	tuple,
+				newtuple;
+	Form_pg_attribute attrtuple;
+	AttrNumber	attnum;
+	Datum		datum,
+				newOptions;
+	bool		isnull;
+	ObjectAddress address;
+	Datum		repl_val[Natts_pg_attribute];
+	bool		repl_null[Natts_pg_attribute];
+	bool		repl_repl[Natts_pg_attribute];
+
+	attrelation = table_open(AttributeRelationId, RowExclusiveLock);
+
+	tuple = SearchSysCacheAttName(RelationGetRelid(rel), colName);
+
+	if (!HeapTupleIsValid(tuple))
+		ereport(ERROR,
+				(errcode(ERRCODE_UNDEFINED_COLUMN),
+				 errmsg("column \"%s\" of relation \"%s\" does not exist",
+						colName, RelationGetRelationName(rel))));
+	attrtuple = (Form_pg_attribute) GETSTRUCT(tuple);
+
+	attnum = attrtuple->attnum;
+	if (attnum <= 0)
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("cannot alter system column \"%s\"",
+						colName)));
+
+	/* Generate new proposed attoptions (text array) */
+	datum = SysCacheGetAttr(ATTNAME, tuple, Anum_pg_attribute_attoptions,
+							&isnull);
+	newOptions = transformRelOptions(isnull ? (Datum) 0 : datum,
+									 castNode(List, options), NULL, NULL,
+									 false, isReset);
+	/* Validate new options */
+	(void) attribute_reloptions(newOptions, true);
+
+	/* Build new tuple. */
+	memset(repl_null, false, sizeof(repl_null));
+	memset(repl_repl, false, sizeof(repl_repl));
+	if (newOptions != (Datum) 0)
+		repl_val[Anum_pg_attribute_attoptions - 1] = newOptions;
+	else
+		repl_null[Anum_pg_attribute_attoptions - 1] = true;
+	repl_repl[Anum_pg_attribute_attoptions - 1] = true;
+	newtuple = heap_modify_tuple(tuple, RelationGetDescr(attrelation),
+								 repl_val, repl_null, repl_repl);
+
+	/* Update system catalog. */
+	CatalogTupleUpdate(attrelation, &newtuple->t_self, newtuple);
+
+	InvokeObjectPostAlterHook(RelationRelationId,
+							  RelationGetRelid(rel),
+							  attrtuple->attnum);
+	ObjectAddressSubSet(address, RelationRelationId,
+						RelationGetRelid(rel), attnum);
+
+	heap_freetuple(newtuple);
+
+	ReleaseSysCache(tuple);
+
+	table_close(attrelation, RowExclusiveLock);
+
+	return address;
+}
+
+/*
+ * Helper function for ATExecSetStorage and ATExecSetCompression
+ *
+ * Set the attstorage and/or attcompression fields for index columns
+ * associated with the specified table column.
+ */
+static void
+SetIndexStorageProperties(Relation rel, Relation attrelation,
+						  AttrNumber attnum,
+						  bool setstorage, char newstorage,
+						  bool setcompression, char newcompression,
+						  LOCKMODE lockmode)
+{
+	ListCell   *lc;
+
+	foreach(lc, RelationGetIndexList(rel))
+	{
+		Oid			indexoid = lfirst_oid(lc);
+		Relation	indrel;
+		AttrNumber	indattnum = 0;
+		HeapTuple	tuple;
+
+		indrel = index_open(indexoid, lockmode);
+
+		for (int i = 0; i < indrel->rd_index->indnatts; i++)
+		{
+			if (indrel->rd_index->indkey.values[i] == attnum)
+			{
+				indattnum = i + 1;
+				break;
+			}
+		}
+
+		if (indattnum == 0)
+		{
+			index_close(indrel, lockmode);
+			continue;
+		}
+
+		tuple = SearchSysCacheCopyAttNum(RelationGetRelid(indrel), indattnum);
+
+		if (HeapTupleIsValid(tuple))
+		{
+			Form_pg_attribute attrtuple = (Form_pg_attribute) GETSTRUCT(tuple);
+
+			if (setstorage)
+				attrtuple->attstorage = newstorage;
+
+			if (setcompression)
+				attrtuple->attcompression = newcompression;
+
+			CatalogTupleUpdate(attrelation, &tuple->t_self, tuple);
+
+			InvokeObjectPostAlterHook(RelationRelationId,
+									  RelationGetRelid(rel),
+									  attrtuple->attnum);
+
+			heap_freetuple(tuple);
+		}
+
+		index_close(indrel, lockmode);
+	}
+}
+
+/*
+ * ALTER TABLE ALTER COLUMN SET STORAGE
+ *
+ * Return value is the address of the modified column
+ */
+static ObjectAddress
+ATExecSetStorage(Relation rel, const char *colName, Node *newValue, LOCKMODE lockmode)
+{
+	char	   *storagemode;
+	char		newstorage;
+	Relation	attrelation;
+	HeapTuple	tuple;
+	Form_pg_attribute attrtuple;
+	AttrNumber	attnum;
+	ObjectAddress address;
+
+	Assert(IsA(newValue, String));
+	storagemode = strVal(newValue);
+
+	if (pg_strcasecmp(storagemode, "plain") == 0)
+		newstorage = TYPSTORAGE_PLAIN;
+	else if (pg_strcasecmp(storagemode, "external") == 0)
+		newstorage = TYPSTORAGE_EXTERNAL;
+	else if (pg_strcasecmp(storagemode, "extended") == 0)
+		newstorage = TYPSTORAGE_EXTENDED;
+	else if (pg_strcasecmp(storagemode, "main") == 0)
+		newstorage = TYPSTORAGE_MAIN;
+	else
+	{
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("invalid storage type \"%s\"",
+						storagemode)));
+		newstorage = 0;			/* keep compiler quiet */
+	}
+
+	attrelation = table_open(AttributeRelationId, RowExclusiveLock);
+
+	tuple = SearchSysCacheCopyAttName(RelationGetRelid(rel), colName);
+
+	if (!HeapTupleIsValid(tuple))
+		ereport(ERROR,
+				(errcode(ERRCODE_UNDEFINED_COLUMN),
+				 errmsg("column \"%s\" of relation \"%s\" does not exist",
+						colName, RelationGetRelationName(rel))));
+	attrtuple = (Form_pg_attribute) GETSTRUCT(tuple);
+
+	attnum = attrtuple->attnum;
+	if (attnum <= 0)
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("cannot alter system column \"%s\"",
+						colName)));
+
+	/*
+	 * safety check: do not allow toasted storage modes unless column datatype
+	 * is TOAST-aware.
+	 */
+	if (newstorage == TYPSTORAGE_PLAIN || TypeIsToastable(attrtuple->atttypid))
+		attrtuple->attstorage = newstorage;
+	else
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("column data type %s can only have storage PLAIN",
+						format_type_be(attrtuple->atttypid))));
+
+	CatalogTupleUpdate(attrelation, &tuple->t_self, tuple);
+
+	InvokeObjectPostAlterHook(RelationRelationId,
+							  RelationGetRelid(rel),
+							  attrtuple->attnum);
+
+	heap_freetuple(tuple);
+
+	/*
+	 * Apply the change to indexes as well (only for simple index columns,
+	 * matching behavior of index.c ConstructTupleDescriptor()).
+	 */
+	SetIndexStorageProperties(rel, attrelation, attnum,
+							  true, newstorage,
+							  false, 0,
+							  lockmode);
+
+	table_close(attrelation, RowExclusiveLock);
+
+	ObjectAddressSubSet(address, RelationRelationId,
+						RelationGetRelid(rel), attnum);
+	return address;
+}
+
+
+/*
+ * ALTER TABLE DROP COLUMN
+ *
+ * DROP COLUMN cannot use the normal ALTER TABLE recursion mechanism,
+ * because we have to decide at runtime whether to recurse or not depending
+ * on whether attinhcount goes to zero or not.  (We can't check this in a
+ * static pre-pass because it won't handle multiple inheritance situations
+ * correctly.)
+ */
+static void
+ATPrepDropColumn(List **wqueue, Relation rel, bool recurse, bool recursing,
+				 AlterTableCmd *cmd, LOCKMODE lockmode,
+				 AlterTableUtilityContext *context)
+{
+	if (rel->rd_rel->reloftype && !recursing)
+		ereport(ERROR,
+				(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+				 errmsg("cannot drop column from typed table")));
+
+	if (rel->rd_rel->relkind == RELKIND_COMPOSITE_TYPE)
+		ATTypedTableRecursion(wqueue, rel, cmd, lockmode, context);
+
+	if (recurse)
+		cmd->subtype = AT_DropColumnRecurse;
+}
+
+/*
+ * Drops column 'colName' from relation 'rel' and returns the address of the
+ * dropped column.  The column is also dropped (or marked as no longer
+ * inherited from relation) from the relation's inheritance children, if any.
+ *
+ * In the recursive invocations for inheritance child relations, instead of
+ * dropping the column directly (if to be dropped at all), its object address
+ * is added to 'addrs', which must be non-NULL in such invocations.  All
+ * columns are dropped at the same time after all the children have been
+ * checked recursively.
+ */
+static ObjectAddress
+ATExecDropColumn(List **wqueue, Relation rel, const char *colName,
+				 DropBehavior behavior,
+				 bool recurse, bool recursing,
+				 bool missing_ok, LOCKMODE lockmode,
+				 ObjectAddresses *addrs)
+{
+	HeapTuple	tuple;
+	Form_pg_attribute targetatt;
+	AttrNumber	attnum;
+	List	   *children;
+	ObjectAddress object;
+	bool		is_expr;
+
+	/* At top level, permission check was done in ATPrepCmd, else do it */
+	if (recursing)
+		ATSimplePermissions(AT_DropColumn, rel, ATT_TABLE | ATT_FOREIGN_TABLE);
+
+	/* Initialize addrs on the first invocation */
+	Assert(!recursing || addrs != NULL);
+	if (!recursing)
+		addrs = new_object_addresses();
+
+	/*
+	 * get the number of the attribute
+	 */
+	tuple = SearchSysCacheAttName(RelationGetRelid(rel), colName);
+	if (!HeapTupleIsValid(tuple))
+	{
+		if (!missing_ok)
+		{
+			ereport(ERROR,
+					(errcode(ERRCODE_UNDEFINED_COLUMN),
+					 errmsg("column \"%s\" of relation \"%s\" does not exist",
+							colName, RelationGetRelationName(rel))));
+		}
+		else
+		{
+			ereport(NOTICE,
+					(errmsg("column \"%s\" of relation \"%s\" does not exist, skipping",
+							colName, RelationGetRelationName(rel))));
+			return InvalidObjectAddress;
+		}
+	}
+	targetatt = (Form_pg_attribute) GETSTRUCT(tuple);
+
+	attnum = targetatt->attnum;
+
+	/* Can't drop a system attribute */
+	if (attnum <= 0)
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("cannot drop system column \"%s\"",
+						colName)));
+
+	/*
+	 * Don't drop inherited columns, unless recursing (presumably from a drop
+	 * of the parent column)
+	 */
+	if (targetatt->attinhcount > 0 && !recursing)
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
+				 errmsg("cannot drop inherited column \"%s\"",
+						colName)));
+
+	/*
+	 * Don't drop columns used in the partition key, either.  (If we let this
+	 * go through, the key column's dependencies would cause a cascaded drop
+	 * of the whole table, which is surely not what the user expected.)
+	 */
+	if (has_partition_attrs(rel,
+							bms_make_singleton(attnum - FirstLowInvalidHeapAttributeNumber),
+							&is_expr))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
+				 errmsg("cannot drop column \"%s\" because it is part of the partition key of relation \"%s\"",
+						colName, RelationGetRelationName(rel))));
+
+	ReleaseSysCache(tuple);
+
+	/*
+	 * Propagate to children as appropriate.  Unlike most other ALTER
+	 * routines, we have to do this one level of recursion at a time; we can't
+	 * use find_all_inheritors to do it in one pass.
+	 */
+	children =
+		find_inheritance_children(RelationGetRelid(rel), lockmode);
+
+	if (children)
+	{
+		Relation	attr_rel;
+		ListCell   *child;
+
+		/*
+		 * In case of a partitioned table, the column must be dropped from the
+		 * partitions as well.
+		 */
+		if (rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE && !recurse)
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
+					 errmsg("cannot drop column from only the partitioned table when partitions exist"),
+					 errhint("Do not specify the ONLY keyword.")));
+
+		attr_rel = table_open(AttributeRelationId, RowExclusiveLock);
+		foreach(child, children)
+		{
+			Oid			childrelid = lfirst_oid(child);
+			Relation	childrel;
+			Form_pg_attribute childatt;
+
+			/* find_inheritance_children already got lock */
+			childrel = table_open(childrelid, NoLock);
+			CheckTableNotInUse(childrel, "ALTER TABLE");
+
+			tuple = SearchSysCacheCopyAttName(childrelid, colName);
+			if (!HeapTupleIsValid(tuple))	/* shouldn't happen */
+				elog(ERROR, "cache lookup failed for attribute \"%s\" of relation %u",
+					 colName, childrelid);
+			childatt = (Form_pg_attribute) GETSTRUCT(tuple);
+
+			if (childatt->attinhcount <= 0) /* shouldn't happen */
+				elog(ERROR, "relation %u has non-inherited attribute \"%s\"",
+					 childrelid, colName);
+
+			if (recurse)
+			{
+				/*
+				 * If the child column has other definition sources, just
+				 * decrement its inheritance count; if not, recurse to delete
+				 * it.
+				 */
+				if (childatt->attinhcount == 1 && !childatt->attislocal)
+				{
+					/* Time to delete this child column, too */
+					ATExecDropColumn(wqueue, childrel, colName,
+									 behavior, true, true,
+									 false, lockmode, addrs);
+				}
+				else
+				{
+					/* Child column must survive my deletion */
+					childatt->attinhcount--;
+
+					CatalogTupleUpdate(attr_rel, &tuple->t_self, tuple);
+
+					/* Make update visible */
+					CommandCounterIncrement();
+				}
+			}
+			else
+			{
+				/*
+				 * If we were told to drop ONLY in this table (no recursion),
+				 * we need to mark the inheritors' attributes as locally
+				 * defined rather than inherited.
+				 */
+				childatt->attinhcount--;
+				childatt->attislocal = true;
+
+				CatalogTupleUpdate(attr_rel, &tuple->t_self, tuple);
+
+				/* Make update visible */
+				CommandCounterIncrement();
+			}
+
+			heap_freetuple(tuple);
+
+			table_close(childrel, NoLock);
+		}
+		table_close(attr_rel, RowExclusiveLock);
+	}
+
+	/* Add object to delete */
+	object.classId = RelationRelationId;
+	object.objectId = RelationGetRelid(rel);
+	object.objectSubId = attnum;
+	add_exact_object_address(&object, addrs);
+
+	if (!recursing)
+	{
+		/* Recursion has ended, drop everything that was collected */
+		performMultipleDeletions(addrs, behavior, 0);
+		free_object_addresses(addrs);
+	}
+
+	return object;
+}
+
+/*
+ * ALTER TABLE ADD INDEX
+ *
+ * There is no such command in the grammar, but parse_utilcmd.c converts
+ * UNIQUE and PRIMARY KEY constraints into AT_AddIndex subcommands.  This lets
+ * us schedule creation of the index at the appropriate time during ALTER.
+ *
+ * Return value is the address of the new index.
+ */
+static ObjectAddress
+ATExecAddIndex(AlteredTableInfo *tab, Relation rel,
+			   IndexStmt *stmt, bool is_rebuild, LOCKMODE lockmode)
+{
+	bool		check_rights;
+	bool		skip_build;
+	bool		quiet;
+	ObjectAddress address;
+
+	Assert(IsA(stmt, IndexStmt));
+	Assert(!stmt->concurrent);
+
+	/* The IndexStmt has already been through transformIndexStmt */
+	Assert(stmt->transformed);
+
+	/* suppress schema rights check when rebuilding existing index */
+	check_rights = !is_rebuild;
+	/* skip index build if phase 3 will do it or we're reusing an old one */
+	skip_build = tab->rewrite > 0 || OidIsValid(stmt->oldNode);
+	/* suppress notices when rebuilding existing index */
+	quiet = is_rebuild;
+
+	address = DefineIndex(RelationGetRelid(rel),
+						  stmt,
+						  InvalidOid,	/* no predefined OID */
+						  InvalidOid,	/* no parent index */
+						  InvalidOid,	/* no parent constraint */
+						  true, /* is_alter_table */
+						  check_rights,
+						  false,	/* check_not_in_use - we did it already */
+						  skip_build,
+						  quiet);
+
+	/*
+	 * If TryReuseIndex() stashed a relfilenode for us, we used it for the new
+	 * index instead of building from scratch.  Restore associated fields.
+	 * This may store InvalidSubTransactionId in both fields, in which case
+	 * relcache.c will assume it can rebuild the relcache entry.  Hence, do
+	 * this after the CCI that made catalog rows visible to any rebuild.  The
+	 * DROP of the old edition of this index will have scheduled the storage
+	 * for deletion at commit, so cancel that pending deletion.
+	 */
+	if (OidIsValid(stmt->oldNode))
+	{
+		Relation	irel = index_open(address.objectId, NoLock);
+
+		irel->rd_createSubid = stmt->oldCreateSubid;
+		irel->rd_firstRelfilenodeSubid = stmt->oldFirstRelfilenodeSubid;
+		RelationPreserveStorage(irel->rd_node, true);
+		index_close(irel, NoLock);
+	}
+
+	return address;
+}
+
+/*
+ * ALTER TABLE ADD STATISTICS
+ *
+ * This is no such command in the grammar, but we use this internally to add
+ * AT_ReAddStatistics subcommands to rebuild extended statistics after a table
+ * column type change.
+ */
+static ObjectAddress
+ATExecAddStatistics(AlteredTableInfo *tab, Relation rel,
+					CreateStatsStmt *stmt, bool is_rebuild, LOCKMODE lockmode)
+{
+	ObjectAddress address;
+
+	Assert(IsA(stmt, CreateStatsStmt));
+
+	/* The CreateStatsStmt has already been through transformStatsStmt */
+	Assert(stmt->transformed);
+
+	address = CreateStatistics(stmt);
+
+	return address;
+}
+
+/*
+ * ALTER TABLE ADD CONSTRAINT USING INDEX
+ *
+ * Returns the address of the new constraint.
+ */
+static ObjectAddress
+ATExecAddIndexConstraint(AlteredTableInfo *tab, Relation rel,
+						 IndexStmt *stmt, LOCKMODE lockmode)
+{
+	Oid			index_oid = stmt->indexOid;
+	Relation	indexRel;
+	char	   *indexName;
+	IndexInfo  *indexInfo;
+	char	   *constraintName;
+	char		constraintType;
+	ObjectAddress address;
+	bits16		flags;
+
+	Assert(IsA(stmt, IndexStmt));
+	Assert(OidIsValid(index_oid));
+	Assert(stmt->isconstraint);
+
+	/*
+	 * Doing this on partitioned tables is not a simple feature to implement,
+	 * so let's punt for now.
+	 */
+	if (rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("ALTER TABLE / ADD CONSTRAINT USING INDEX is not supported on partitioned tables")));
+
+	indexRel = index_open(index_oid, AccessShareLock);
+
+	indexName = pstrdup(RelationGetRelationName(indexRel));
+
+	indexInfo = BuildIndexInfo(indexRel);
+
+	/* this should have been checked at parse time */
+	if (!indexInfo->ii_Unique)
+		elog(ERROR, "index \"%s\" is not unique", indexName);
+
+	/*
+	 * Determine name to assign to constraint.  We require a constraint to
+	 * have the same name as the underlying index; therefore, use the index's
+	 * existing name as the default constraint name, and if the user
+	 * explicitly gives some other name for the constraint, rename the index
+	 * to match.
+	 */
+	constraintName = stmt->idxname;
+	if (constraintName == NULL)
+		constraintName = indexName;
+	else if (strcmp(constraintName, indexName) != 0)
+	{
+		ereport(NOTICE,
+				(errmsg("ALTER TABLE / ADD CONSTRAINT USING INDEX will rename index \"%s\" to \"%s\"",
+						indexName, constraintName)));
+		RenameRelationInternal(index_oid, constraintName, false, true);
+	}
+
+	/* Extra checks needed if making primary key */
+	if (stmt->primary)
+		index_check_primary_key(rel, indexInfo, true, stmt);
+
+	/* Note we currently don't support EXCLUSION constraints here */
+	if (stmt->primary)
+		constraintType = CONSTRAINT_PRIMARY;
+	else
+		constraintType = CONSTRAINT_UNIQUE;
+
+	/* Create the catalog entries for the constraint */
+	flags = INDEX_CONSTR_CREATE_UPDATE_INDEX |
+		INDEX_CONSTR_CREATE_REMOVE_OLD_DEPS |
+		(stmt->initdeferred ? INDEX_CONSTR_CREATE_INIT_DEFERRED : 0) |
+		(stmt->deferrable ? INDEX_CONSTR_CREATE_DEFERRABLE : 0) |
+		(stmt->primary ? INDEX_CONSTR_CREATE_MARK_AS_PRIMARY : 0);
+
+	address = index_constraint_create(rel,
+									  index_oid,
+									  InvalidOid,
+									  indexInfo,
+									  constraintName,
+									  constraintType,
+									  flags,
+									  allowSystemTableMods,
+									  false);	/* is_internal */
+
+	index_close(indexRel, NoLock);
+
+	return address;
+}
+
+/*
+ * ALTER TABLE ADD CONSTRAINT
+ *
+ * Return value is the address of the new constraint; if no constraint was
+ * added, InvalidObjectAddress is returned.
+ */
+static ObjectAddress
+ATExecAddConstraint(List **wqueue, AlteredTableInfo *tab, Relation rel,
+					Constraint *newConstraint, bool recurse, bool is_readd,
+					LOCKMODE lockmode)
+{
+	ObjectAddress address = InvalidObjectAddress;
+
+	Assert(IsA(newConstraint, Constraint));
+
+	/*
+	 * Currently, we only expect to see CONSTR_CHECK and CONSTR_FOREIGN nodes
+	 * arriving here (see the preprocessing done in parse_utilcmd.c).  Use a
+	 * switch anyway to make it easier to add more code later.
+	 */
+	switch (newConstraint->contype)
+	{
+		case CONSTR_CHECK:
+			address =
+				ATAddCheckConstraint(wqueue, tab, rel,
+									 newConstraint, recurse, false, is_readd,
+									 lockmode);
+			break;
+
+		case CONSTR_FOREIGN:
+
+			/*
+			 * Assign or validate constraint name
+			 */
+			if (newConstraint->conname)
+			{
+				if (ConstraintNameIsUsed(CONSTRAINT_RELATION,
+										 RelationGetRelid(rel),
+										 newConstraint->conname))
+					ereport(ERROR,
+							(errcode(ERRCODE_DUPLICATE_OBJECT),
+							 errmsg("constraint \"%s\" for relation \"%s\" already exists",
+									newConstraint->conname,
+									RelationGetRelationName(rel))));
+			}
+			else
+				newConstraint->conname =
+					ChooseConstraintName(RelationGetRelationName(rel),
+										 ChooseForeignKeyConstraintNameAddition(newConstraint->fk_attrs),
+										 "fkey",
+										 RelationGetNamespace(rel),
+										 NIL);
+
+			address = ATAddForeignKeyConstraint(wqueue, tab, rel,
+												newConstraint,
+												recurse, false,
+												lockmode);
+			break;
+
+		default:
+			elog(ERROR, "unrecognized constraint type: %d",
+				 (int) newConstraint->contype);
+	}
+
+	return address;
+}
+
+/*
+ * Generate the column-name portion of the constraint name for a new foreign
+ * key given the list of column names that reference the referenced
+ * table.  This will be passed to ChooseConstraintName along with the parent
+ * table name and the "fkey" suffix.
+ *
+ * We know that less than NAMEDATALEN characters will actually be used, so we
+ * can truncate the result once we've generated that many.
+ *
+ * XXX see also ChooseExtendedStatisticNameAddition and
+ * ChooseIndexNameAddition.
+ */
+static char *
+ChooseForeignKeyConstraintNameAddition(List *colnames)
+{
+	char		buf[NAMEDATALEN * 2];
+	int			buflen = 0;
+	ListCell   *lc;
+
+	buf[0] = '\0';
+	foreach(lc, colnames)
+	{
+		const char *name = strVal(lfirst(lc));
+
+		if (buflen > 0)
+			buf[buflen++] = '_';	/* insert _ between names */
+
+		/*
+		 * At this point we have buflen <= NAMEDATALEN.  name should be less
+		 * than NAMEDATALEN already, but use strlcpy for paranoia.
+		 */
+		strlcpy(buf + buflen, name, NAMEDATALEN);
+		buflen += strlen(buf + buflen);
+		if (buflen >= NAMEDATALEN)
+			break;
+	}
+	return pstrdup(buf);
+}
+
+/*
+ * Add a check constraint to a single table and its children.  Returns the
+ * address of the constraint added to the parent relation, if one gets added,
+ * or InvalidObjectAddress otherwise.
+ *
+ * Subroutine for ATExecAddConstraint.
+ *
+ * We must recurse to child tables during execution, rather than using
+ * ALTER TABLE's normal prep-time recursion.  The reason is that all the
+ * constraints *must* be given the same name, else they won't be seen as
+ * related later.  If the user didn't explicitly specify a name, then
+ * AddRelationNewConstraints would normally assign different names to the
+ * child constraints.  To fix that, we must capture the name assigned at
+ * the parent table and pass that down.
+ */
+static ObjectAddress
+ATAddCheckConstraint(List **wqueue, AlteredTableInfo *tab, Relation rel,
+					 Constraint *constr, bool recurse, bool recursing,
+					 bool is_readd, LOCKMODE lockmode)
+{
+	List	   *newcons;
+	ListCell   *lcon;
+	List	   *children;
+	ListCell   *child;
+	ObjectAddress address = InvalidObjectAddress;
+
+	/* At top level, permission check was done in ATPrepCmd, else do it */
+	if (recursing)
+		ATSimplePermissions(AT_AddConstraint, rel, ATT_TABLE | ATT_FOREIGN_TABLE);
+
+	/*
+	 * Call AddRelationNewConstraints to do the work, making sure it works on
+	 * a copy of the Constraint so transformExpr can't modify the original. It
+	 * returns a list of cooked constraints.
+	 *
+	 * If the constraint ends up getting merged with a pre-existing one, it's
+	 * omitted from the returned list, which is what we want: we do not need
+	 * to do any validation work.  That can only happen at child tables,
+	 * though, since we disallow merging at the top level.
+	 */
+	newcons = AddRelationNewConstraints(rel, NIL,
+										list_make1(copyObject(constr)),
+										recursing | is_readd,	/* allow_merge */
+										!recursing, /* is_local */
+										is_readd,	/* is_internal */
+										NULL);	/* queryString not available
+												 * here */
+
+	/* we don't expect more than one constraint here */
+	Assert(list_length(newcons) <= 1);
+
+	/* Add each to-be-validated constraint to Phase 3's queue */
+	foreach(lcon, newcons)
+	{
+		CookedConstraint *ccon = (CookedConstraint *) lfirst(lcon);
+
+		if (!ccon->skip_validation)
+		{
+			NewConstraint *newcon;
+
+			newcon = (NewConstraint *) palloc0(sizeof(NewConstraint));
+			newcon->name = ccon->name;
+			newcon->contype = ccon->contype;
+			newcon->qual = ccon->expr;
+
+			tab->constraints = lappend(tab->constraints, newcon);
+		}
+
+		/* Save the actually assigned name if it was defaulted */
+		if (constr->conname == NULL)
+			constr->conname = ccon->name;
+
+		ObjectAddressSet(address, ConstraintRelationId, ccon->conoid);
+	}
+
+	/* At this point we must have a locked-down name to use */
+	Assert(constr->conname != NULL);
+
+	/* Advance command counter in case same table is visited multiple times */
+	CommandCounterIncrement();
+
+	/*
+	 * If the constraint got merged with an existing constraint, we're done.
+	 * We mustn't recurse to child tables in this case, because they've
+	 * already got the constraint, and visiting them again would lead to an
+	 * incorrect value for coninhcount.
+	 */
+	if (newcons == NIL)
+		return address;
+
+	/*
+	 * If adding a NO INHERIT constraint, no need to find our children.
+	 */
+	if (constr->is_no_inherit)
+		return address;
+
+	/*
+	 * Propagate to children as appropriate.  Unlike most other ALTER
+	 * routines, we have to do this one level of recursion at a time; we can't
+	 * use find_all_inheritors to do it in one pass.
+	 */
+	children =
+		find_inheritance_children(RelationGetRelid(rel), lockmode);
+
+	/*
+	 * Check if ONLY was specified with ALTER TABLE.  If so, allow the
+	 * constraint creation only if there are no children currently.  Error out
+	 * otherwise.
+	 */
+	if (!recurse && children != NIL)
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
+				 errmsg("constraint must be added to child tables too")));
+
+	foreach(child, children)
+	{
+		Oid			childrelid = lfirst_oid(child);
+		Relation	childrel;
+		AlteredTableInfo *childtab;
+
+		/* find_inheritance_children already got lock */
+		childrel = table_open(childrelid, NoLock);
+		CheckTableNotInUse(childrel, "ALTER TABLE");
+
+		/* Find or create work queue entry for this table */
+		childtab = ATGetQueueEntry(wqueue, childrel);
+
+		/* Recurse to child */
+		ATAddCheckConstraint(wqueue, childtab, childrel,
+							 constr, recurse, true, is_readd, lockmode);
+
+		table_close(childrel, NoLock);
+	}
+
+	return address;
+}
+
+/*
+ * Add a foreign-key constraint to a single table; return the new constraint's
+ * address.
+ *
+ * Subroutine for ATExecAddConstraint.  Must already hold exclusive
+ * lock on the rel, and have done appropriate validity checks for it.
+ * We do permissions checks here, however.
+ *
+ * When the referenced or referencing tables (or both) are partitioned,
+ * multiple pg_constraint rows are required -- one for each partitioned table
+ * and each partition on each side (fortunately, not one for every combination
+ * thereof).  We also need action triggers on each leaf partition on the
+ * referenced side, and check triggers on each leaf partition on the
+ * referencing side.
+ */
+static ObjectAddress
+ATAddForeignKeyConstraint(List **wqueue, AlteredTableInfo *tab, Relation rel,
+						  Constraint *fkconstraint,
+						  bool recurse, bool recursing, LOCKMODE lockmode)
+{
+	Relation	pkrel;
+	int16		pkattnum[INDEX_MAX_KEYS];
+	int16		fkattnum[INDEX_MAX_KEYS];
+	Oid			pktypoid[INDEX_MAX_KEYS];
+	Oid			fktypoid[INDEX_MAX_KEYS];
+	Oid			opclasses[INDEX_MAX_KEYS];
+	Oid			pfeqoperators[INDEX_MAX_KEYS];
+	Oid			ppeqoperators[INDEX_MAX_KEYS];
+	Oid			ffeqoperators[INDEX_MAX_KEYS];
+	int16		fkdelsetcols[INDEX_MAX_KEYS];
+	int			i;
+	int			numfks,
+				numpks,
+				numfkdelsetcols;
+	Oid			indexOid;
+	bool		old_check_ok;
+	ObjectAddress address;
+	ListCell   *old_pfeqop_item = list_head(fkconstraint->old_conpfeqop);
+
+	/*
+	 * Grab ShareRowExclusiveLock on the pk table, so that someone doesn't
+	 * delete rows out from under us.
+	 */
+	if (OidIsValid(fkconstraint->old_pktable_oid))
+		pkrel = table_open(fkconstraint->old_pktable_oid, ShareRowExclusiveLock);
+	else
+		pkrel = table_openrv(fkconstraint->pktable, ShareRowExclusiveLock);
+
+	/*
+	 * Validity checks (permission checks wait till we have the column
+	 * numbers)
+	 */
+	if (rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
+	{
+		if (!recurse)
+			ereport(ERROR,
+					(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+					 errmsg("cannot use ONLY for foreign key on partitioned table \"%s\" referencing relation \"%s\"",
+							RelationGetRelationName(rel),
+							RelationGetRelationName(pkrel))));
+		if (fkconstraint->skip_validation && !fkconstraint->initially_valid)
+			ereport(ERROR,
+					(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+					 errmsg("cannot add NOT VALID foreign key on partitioned table \"%s\" referencing relation \"%s\"",
+							RelationGetRelationName(rel),
+							RelationGetRelationName(pkrel)),
+					 errdetail("This feature is not yet supported on partitioned tables.")));
+	}
+
+	if (pkrel->rd_rel->relkind != RELKIND_RELATION &&
+		pkrel->rd_rel->relkind != RELKIND_PARTITIONED_TABLE)
+		ereport(ERROR,
+				(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+				 errmsg("referenced relation \"%s\" is not a table",
+						RelationGetRelationName(pkrel))));
+
+	if (!allowSystemTableMods && IsSystemRelation(pkrel))
+		ereport(ERROR,
+				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
+				 errmsg("permission denied: \"%s\" is a system catalog",
+						RelationGetRelationName(pkrel))));
+
+	/*
+	 * References from permanent or unlogged tables to temp tables, and from
+	 * permanent tables to unlogged tables, are disallowed because the
+	 * referenced data can vanish out from under us.  References from temp
+	 * tables to any other table type are also disallowed, because other
+	 * backends might need to run the RI triggers on the perm table, but they
+	 * can't reliably see tuples in the local buffers of other backends.
+	 */
+	switch (rel->rd_rel->relpersistence)
+	{
+		case RELPERSISTENCE_PERMANENT:
+			if (!RelationIsPermanent(pkrel))
+				ereport(ERROR,
+						(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
+						 errmsg("constraints on permanent tables may reference only permanent tables")));
+			break;
+		case RELPERSISTENCE_UNLOGGED:
+			if (!RelationIsPermanent(pkrel)
+				&& pkrel->rd_rel->relpersistence != RELPERSISTENCE_UNLOGGED)
+				ereport(ERROR,
+						(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
+						 errmsg("constraints on unlogged tables may reference only permanent or unlogged tables")));
+			break;
+		case RELPERSISTENCE_TEMP:
+			if (pkrel->rd_rel->relpersistence != RELPERSISTENCE_TEMP)
+				ereport(ERROR,
+						(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
+						 errmsg("constraints on temporary tables may reference only temporary tables")));
+			if (!pkrel->rd_islocaltemp || !rel->rd_islocaltemp)
+				ereport(ERROR,
+						(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
+						 errmsg("constraints on temporary tables must involve temporary tables of this session")));
+			break;
+	}
+
+	/*
+	 * Look up the referencing attributes to make sure they exist, and record
+	 * their attnums and type OIDs.
+	 */
+	MemSet(pkattnum, 0, sizeof(pkattnum));
+	MemSet(fkattnum, 0, sizeof(fkattnum));
+	MemSet(pktypoid, 0, sizeof(pktypoid));
+	MemSet(fktypoid, 0, sizeof(fktypoid));
+	MemSet(opclasses, 0, sizeof(opclasses));
+	MemSet(pfeqoperators, 0, sizeof(pfeqoperators));
+	MemSet(ppeqoperators, 0, sizeof(ppeqoperators));
+	MemSet(ffeqoperators, 0, sizeof(ffeqoperators));
+	MemSet(fkdelsetcols, 0, sizeof(fkdelsetcols));
+
+	numfks = transformColumnNameList(RelationGetRelid(rel),
+									 fkconstraint->fk_attrs,
+									 fkattnum, fktypoid);
+
+	numfkdelsetcols = transformColumnNameList(RelationGetRelid(rel),
+											  fkconstraint->fk_del_set_cols,
+											  fkdelsetcols, NULL);
+	validateFkOnDeleteSetColumns(numfks, fkattnum,
+								 numfkdelsetcols, fkdelsetcols,
+								 fkconstraint->fk_del_set_cols);
+
+	/*
+	 * If the attribute list for the referenced table was omitted, lookup the
+	 * definition of the primary key and use it.  Otherwise, validate the
+	 * supplied attribute list.  In either case, discover the index OID and
+	 * index opclasses, and the attnums and type OIDs of the attributes.
+	 */
+	if (fkconstraint->pk_attrs == NIL)
+	{
+		numpks = transformFkeyGetPrimaryKey(pkrel, &indexOid,
+											&fkconstraint->pk_attrs,
+											pkattnum, pktypoid,
+											opclasses);
+	}
+	else
+	{
+		numpks = transformColumnNameList(RelationGetRelid(pkrel),
+										 fkconstraint->pk_attrs,
+										 pkattnum, pktypoid);
+		/* Look for an index matching the column list */
+		indexOid = transformFkeyCheckAttrs(pkrel, numpks, pkattnum,
+										   opclasses);
+	}
+
+	/*
+	 * Now we can check permissions.
+	 */
+	checkFkeyPermissions(pkrel, pkattnum, numpks);
+
+	/*
+	 * Check some things for generated columns.
+	 */
+	for (i = 0; i < numfks; i++)
+	{
+		char		attgenerated = TupleDescAttr(RelationGetDescr(rel), fkattnum[i] - 1)->attgenerated;
+
+		if (attgenerated)
+		{
+			/*
+			 * Check restrictions on UPDATE/DELETE actions, per SQL standard
+			 */
+			if (fkconstraint->fk_upd_action == FKCONSTR_ACTION_SETNULL ||
+				fkconstraint->fk_upd_action == FKCONSTR_ACTION_SETDEFAULT ||
+				fkconstraint->fk_upd_action == FKCONSTR_ACTION_CASCADE)
+				ereport(ERROR,
+						(errcode(ERRCODE_SYNTAX_ERROR),
+						 errmsg("invalid %s action for foreign key constraint containing generated column",
+								"ON UPDATE")));
+			if (fkconstraint->fk_del_action == FKCONSTR_ACTION_SETNULL ||
+				fkconstraint->fk_del_action == FKCONSTR_ACTION_SETDEFAULT)
+				ereport(ERROR,
+						(errcode(ERRCODE_SYNTAX_ERROR),
+						 errmsg("invalid %s action for foreign key constraint containing generated column",
+								"ON DELETE")));
+		}
+	}
+
+	/*
+	 * Look up the equality operators to use in the constraint.
+	 *
+	 * Note that we have to be careful about the difference between the actual
+	 * PK column type and the opclass' declared input type, which might be
+	 * only binary-compatible with it.  The declared opcintype is the right
+	 * thing to probe pg_amop with.
+	 */
+	if (numfks != numpks)
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_FOREIGN_KEY),
+				 errmsg("number of referencing and referenced columns for foreign key disagree")));
+
+	/*
+	 * On the strength of a previous constraint, we might avoid scanning
+	 * tables to validate this one.  See below.
+	 */
+	old_check_ok = (fkconstraint->old_conpfeqop != NIL);
+	Assert(!old_check_ok || numfks == list_length(fkconstraint->old_conpfeqop));
+
+	for (i = 0; i < numpks; i++)
+	{
+		Oid			pktype = pktypoid[i];
+		Oid			fktype = fktypoid[i];
+		Oid			fktyped;
+		HeapTuple	cla_ht;
+		Form_pg_opclass cla_tup;
+		Oid			amid;
+		Oid			opfamily;
+		Oid			opcintype;
+		Oid			pfeqop;
+		Oid			ppeqop;
+		Oid			ffeqop;
+		int16		eqstrategy;
+		Oid			pfeqop_right;
+
+		/* We need several fields out of the pg_opclass entry */
+		cla_ht = SearchSysCache1(CLAOID, ObjectIdGetDatum(opclasses[i]));
+		if (!HeapTupleIsValid(cla_ht))
+			elog(ERROR, "cache lookup failed for opclass %u", opclasses[i]);
+		cla_tup = (Form_pg_opclass) GETSTRUCT(cla_ht);
+		amid = cla_tup->opcmethod;
+		opfamily = cla_tup->opcfamily;
+		opcintype = cla_tup->opcintype;
+		ReleaseSysCache(cla_ht);
+
+		/*
+		 * Check it's a btree; currently this can never fail since no other
+		 * index AMs support unique indexes.  If we ever did have other types
+		 * of unique indexes, we'd need a way to determine which operator
+		 * strategy number is equality.  (Is it reasonable to insist that
+		 * every such index AM use btree's number for equality?)
+		 */
+		if (amid != BTREE_AM_OID)
+			elog(ERROR, "only b-tree indexes are supported for foreign keys");
+		eqstrategy = BTEqualStrategyNumber;
+
+		/*
+		 * There had better be a primary equality operator for the index.
+		 * We'll use it for PK = PK comparisons.
+		 */
+		ppeqop = get_opfamily_member(opfamily, opcintype, opcintype,
+									 eqstrategy);
+
+		if (!OidIsValid(ppeqop))
+			elog(ERROR, "missing operator %d(%u,%u) in opfamily %u",
+				 eqstrategy, opcintype, opcintype, opfamily);
+
+		/*
+		 * Are there equality operators that take exactly the FK type? Assume
+		 * we should look through any domain here.
+		 */
+		fktyped = getBaseType(fktype);
+
+		pfeqop = get_opfamily_member(opfamily, opcintype, fktyped,
+									 eqstrategy);
+		if (OidIsValid(pfeqop))
+		{
+			pfeqop_right = fktyped;
+			ffeqop = get_opfamily_member(opfamily, fktyped, fktyped,
+										 eqstrategy);
+		}
+		else
+		{
+			/* keep compiler quiet */
+			pfeqop_right = InvalidOid;
+			ffeqop = InvalidOid;
+		}
+
+		if (!(OidIsValid(pfeqop) && OidIsValid(ffeqop)))
+		{
+			/*
+			 * Otherwise, look for an implicit cast from the FK type to the
+			 * opcintype, and if found, use the primary equality operator.
+			 * This is a bit tricky because opcintype might be a polymorphic
+			 * type such as ANYARRAY or ANYENUM; so what we have to test is
+			 * whether the two actual column types can be concurrently cast to
+			 * that type.  (Otherwise, we'd fail to reject combinations such
+			 * as int[] and point[].)
+			 */
+			Oid			input_typeids[2];
+			Oid			target_typeids[2];
+
+			input_typeids[0] = pktype;
+			input_typeids[1] = fktype;
+			target_typeids[0] = opcintype;
+			target_typeids[1] = opcintype;
+			if (can_coerce_type(2, input_typeids, target_typeids,
+								COERCION_IMPLICIT))
+			{
+				pfeqop = ffeqop = ppeqop;
+				pfeqop_right = opcintype;
+			}
+		}
+
+		if (!(OidIsValid(pfeqop) && OidIsValid(ffeqop)))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("foreign key constraint \"%s\" cannot be implemented",
+							fkconstraint->conname),
+					 errdetail("Key columns \"%s\" and \"%s\" "
+							   "are of incompatible types: %s and %s.",
+							   strVal(list_nth(fkconstraint->fk_attrs, i)),
+							   strVal(list_nth(fkconstraint->pk_attrs, i)),
+							   format_type_be(fktype),
+							   format_type_be(pktype))));
+
+		if (old_check_ok)
+		{
+			/*
+			 * When a pfeqop changes, revalidate the constraint.  We could
+			 * permit intra-opfamily changes, but that adds subtle complexity
+			 * without any concrete benefit for core types.  We need not
+			 * assess ppeqop or ffeqop, which RI_Initial_Check() does not use.
+			 */
+			old_check_ok = (pfeqop == lfirst_oid(old_pfeqop_item));
+			old_pfeqop_item = lnext(fkconstraint->old_conpfeqop,
+									old_pfeqop_item);
+		}
+		if (old_check_ok)
+		{
+			Oid			old_fktype;
+			Oid			new_fktype;
+			CoercionPathType old_pathtype;
+			CoercionPathType new_pathtype;
+			Oid			old_castfunc;
+			Oid			new_castfunc;
+			Form_pg_attribute attr = TupleDescAttr(tab->oldDesc,
+												   fkattnum[i] - 1);
+
+			/*
+			 * Identify coercion pathways from each of the old and new FK-side
+			 * column types to the right (foreign) operand type of the pfeqop.
+			 * We may assume that pg_constraint.conkey is not changing.
+			 */
+			old_fktype = attr->atttypid;
+			new_fktype = fktype;
+			old_pathtype = findFkeyCast(pfeqop_right, old_fktype,
+										&old_castfunc);
+			new_pathtype = findFkeyCast(pfeqop_right, new_fktype,
+										&new_castfunc);
+
+			/*
+			 * Upon a change to the cast from the FK column to its pfeqop
+			 * operand, revalidate the constraint.  For this evaluation, a
+			 * binary coercion cast is equivalent to no cast at all.  While
+			 * type implementors should design implicit casts with an eye
+			 * toward consistency of operations like equality, we cannot
+			 * assume here that they have done so.
+			 *
+			 * A function with a polymorphic argument could change behavior
+			 * arbitrarily in response to get_fn_expr_argtype().  Therefore,
+			 * when the cast destination is polymorphic, we only avoid
+			 * revalidation if the input type has not changed at all.  Given
+			 * just the core data types and operator classes, this requirement
+			 * prevents no would-be optimizations.
+			 *
+			 * If the cast converts from a base type to a domain thereon, then
+			 * that domain type must be the opcintype of the unique index.
+			 * Necessarily, the primary key column must then be of the domain
+			 * type.  Since the constraint was previously valid, all values on
+			 * the foreign side necessarily exist on the primary side and in
+			 * turn conform to the domain.  Consequently, we need not treat
+			 * domains specially here.
+			 *
+			 * Since we require that all collations share the same notion of
+			 * equality (which they do, because texteq reduces to bitwise
+			 * equality), we don't compare collation here.
+			 *
+			 * We need not directly consider the PK type.  It's necessarily
+			 * binary coercible to the opcintype of the unique index column,
+			 * and ri_triggers.c will only deal with PK datums in terms of
+			 * that opcintype.  Changing the opcintype also changes pfeqop.
+			 */
+			old_check_ok = (new_pathtype == old_pathtype &&
+							new_castfunc == old_castfunc &&
+							(!IsPolymorphicType(pfeqop_right) ||
+							 new_fktype == old_fktype));
+		}
+
+		pfeqoperators[i] = pfeqop;
+		ppeqoperators[i] = ppeqop;
+		ffeqoperators[i] = ffeqop;
+	}
+
+	/*
+	 * Create all the constraint and trigger objects, recursing to partitions
+	 * as necessary.  First handle the referenced side.
+	 */
+	address = addFkRecurseReferenced(wqueue, fkconstraint, rel, pkrel,
+									 indexOid,
+									 InvalidOid,	/* no parent constraint */
+									 numfks,
+									 pkattnum,
+									 fkattnum,
+									 pfeqoperators,
+									 ppeqoperators,
+									 ffeqoperators,
+									 numfkdelsetcols,
+									 fkdelsetcols,
+									 old_check_ok,
+									 InvalidOid, InvalidOid);
+
+	/* Now handle the referencing side. */
+	addFkRecurseReferencing(wqueue, fkconstraint, rel, pkrel,
+							indexOid,
+							address.objectId,
+							numfks,
+							pkattnum,
+							fkattnum,
+							pfeqoperators,
+							ppeqoperators,
+							ffeqoperators,
+							numfkdelsetcols,
+							fkdelsetcols,
+							old_check_ok,
+							lockmode,
+							InvalidOid, InvalidOid);
+
+	/*
+	 * Done.  Close pk table, but keep lock until we've committed.
+	 */
+	table_close(pkrel, NoLock);
+
+	return address;
+}
+
+/*
+ * validateFkOnDeleteSetColumns
+ *		Verifies that columns used in ON DELETE SET NULL/DEFAULT (...)
+ *		column lists are valid.
+ */
+void
+validateFkOnDeleteSetColumns(int numfks, const int16 *fkattnums,
+							 int numfksetcols, const int16 *fksetcolsattnums,
+							 List *fksetcols)
+{
+	for (int i = 0; i < numfksetcols; i++)
+	{
+		int16		setcol_attnum = fksetcolsattnums[i];
+		bool		seen = false;
+
+		for (int j = 0; j < numfks; j++)
+		{
+			if (fkattnums[j] == setcol_attnum)
+			{
+				seen = true;
+				break;
+			}
+		}
+
+		if (!seen)
+		{
+			char	   *col = strVal(list_nth(fksetcols, i));
+
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_COLUMN_REFERENCE),
+					 errmsg("column \"%s\" referenced in ON DELETE SET action must be part of foreign key", col)));
+		}
+	}
+}
+
+/*
+ * addFkRecurseReferenced
+ *		subroutine for ATAddForeignKeyConstraint; recurses on the referenced
+ *		side of the constraint
+ *
+ * Create pg_constraint rows for the referenced side of the constraint,
+ * referencing the parent of the referencing side; also create action triggers
+ * on leaf partitions.  If the table is partitioned, recurse to handle each
+ * partition.
+ *
+ * wqueue is the ALTER TABLE work queue; can be NULL when not running as part
+ * of an ALTER TABLE sequence.
+ * fkconstraint is the constraint being added.
+ * rel is the root referencing relation.
+ * pkrel is the referenced relation; might be a partition, if recursing.
+ * indexOid is the OID of the index (on pkrel) implementing this constraint.
+ * parentConstr is the OID of a parent constraint; InvalidOid if this is a
+ * top-level constraint.
+ * numfks is the number of columns in the foreign key
+ * pkattnum is the attnum array of referenced attributes.
+ * fkattnum is the attnum array of referencing attributes.
+ * numfkdelsetcols is the number of columns in the ON DELETE SET NULL/DEFAULT
+ *      (...) clause
+ * fkdelsetcols is the attnum array of the columns in the ON DELETE SET
+ *      NULL/DEFAULT clause
+ * pf/pp/ffeqoperators are OID array of operators between columns.
+ * old_check_ok signals that this constraint replaces an existing one that
+ * was already validated (thus this one doesn't need validation).
+ * parentDelTrigger and parentUpdTrigger, when being recursively called on
+ * a partition, are the OIDs of the parent action triggers for DELETE and
+ * UPDATE respectively.
+ */
+static ObjectAddress
+addFkRecurseReferenced(List **wqueue, Constraint *fkconstraint, Relation rel,
+					   Relation pkrel, Oid indexOid, Oid parentConstr,
+					   int numfks,
+					   int16 *pkattnum, int16 *fkattnum, Oid *pfeqoperators,
+					   Oid *ppeqoperators, Oid *ffeqoperators,
+					   int numfkdelsetcols, int16 *fkdelsetcols,
+					   bool old_check_ok,
+					   Oid parentDelTrigger, Oid parentUpdTrigger)
+{
+	ObjectAddress address;
+	Oid			constrOid;
+	char	   *conname;
+	bool		conislocal;
+	int			coninhcount;
+	bool		connoinherit;
+	Oid			deleteTriggerOid,
+				updateTriggerOid;
+
+	/*
+	 * Verify relkind for each referenced partition.  At the top level, this
+	 * is redundant with a previous check, but we need it when recursing.
+	 */
+	if (pkrel->rd_rel->relkind != RELKIND_RELATION &&
+		pkrel->rd_rel->relkind != RELKIND_PARTITIONED_TABLE)
+		ereport(ERROR,
+				(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+				 errmsg("referenced relation \"%s\" is not a table",
+						RelationGetRelationName(pkrel))));
+
+	/*
+	 * Caller supplies us with a constraint name; however, it may be used in
+	 * this partition, so come up with a different one in that case.
+	 */
+	if (ConstraintNameIsUsed(CONSTRAINT_RELATION,
+							 RelationGetRelid(rel),
+							 fkconstraint->conname))
+		conname = ChooseConstraintName(RelationGetRelationName(rel),
+									   ChooseForeignKeyConstraintNameAddition(fkconstraint->fk_attrs),
+									   "fkey",
+									   RelationGetNamespace(rel), NIL);
+	else
+		conname = fkconstraint->conname;
+
+	if (OidIsValid(parentConstr))
+	{
+		conislocal = false;
+		coninhcount = 1;
+		connoinherit = false;
+	}
+	else
+	{
+		conislocal = true;
+		coninhcount = 0;
+
+		/*
+		 * always inherit for partitioned tables, never for legacy inheritance
+		 */
+		connoinherit = rel->rd_rel->relkind != RELKIND_PARTITIONED_TABLE;
+	}
+
+	/*
+	 * Record the FK constraint in pg_constraint.
+	 */
+	constrOid = CreateConstraintEntry(conname,
+									  RelationGetNamespace(rel),
+									  CONSTRAINT_FOREIGN,
+									  fkconstraint->deferrable,
+									  fkconstraint->initdeferred,
+									  fkconstraint->initially_valid,
+									  parentConstr,
+									  RelationGetRelid(rel),
+									  fkattnum,
+									  numfks,
+									  numfks,
+									  InvalidOid,	/* not a domain constraint */
+									  indexOid,
+									  RelationGetRelid(pkrel),
+									  pkattnum,
+									  pfeqoperators,
+									  ppeqoperators,
+									  ffeqoperators,
+									  numfks,
+									  fkconstraint->fk_upd_action,
+									  fkconstraint->fk_del_action,
+									  fkdelsetcols,
+									  numfkdelsetcols,
+									  fkconstraint->fk_matchtype,
+									  NULL, /* no exclusion constraint */
+									  NULL, /* no check constraint */
+									  NULL,
+									  conislocal,	/* islocal */
+									  coninhcount,	/* inhcount */
+									  connoinherit, /* conNoInherit */
+									  false);	/* is_internal */
+
+	ObjectAddressSet(address, ConstraintRelationId, constrOid);
+
+	/*
+	 * Mark the child constraint as part of the parent constraint; it must not
+	 * be dropped on its own.  (This constraint is deleted when the partition
+	 * is detached, but a special check needs to occur that the partition
+	 * contains no referenced values.)
+	 */
+	if (OidIsValid(parentConstr))
+	{
+		ObjectAddress referenced;
+
+		ObjectAddressSet(referenced, ConstraintRelationId, parentConstr);
+		recordDependencyOn(&address, &referenced, DEPENDENCY_INTERNAL);
+	}
+
+	/* make new constraint visible, in case we add more */
+	CommandCounterIncrement();
+
+	/*
+	 * Create the action triggers that enforce the constraint.
+	 */
+	createForeignKeyActionTriggers(rel, RelationGetRelid(pkrel),
+								   fkconstraint,
+								   constrOid, indexOid,
+								   parentDelTrigger, parentUpdTrigger,
+								   &deleteTriggerOid, &updateTriggerOid);
+
+	/*
+	 * If the referenced table is partitioned, recurse on ourselves to handle
+	 * each partition.  We need one pg_constraint row created for each
+	 * partition in addition to the pg_constraint row for the parent table.
+	 */
+	if (pkrel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
+	{
+		PartitionDesc pd = RelationGetPartitionDesc(pkrel, true);
+
+		for (int i = 0; i < pd->nparts; i++)
+		{
+			Relation	partRel;
+			AttrMap    *map;
+			AttrNumber *mapped_pkattnum;
+			Oid			partIndexId;
+
+			partRel = table_open(pd->oids[i], ShareRowExclusiveLock);
+
+			/*
+			 * Map the attribute numbers in the referenced side of the FK
+			 * definition to match the partition's column layout.
+			 */
+			map = build_attrmap_by_name_if_req(RelationGetDescr(partRel),
+											   RelationGetDescr(pkrel));
+			if (map)
+			{
+				mapped_pkattnum = palloc(sizeof(AttrNumber) * numfks);
+				for (int j = 0; j < numfks; j++)
+					mapped_pkattnum[j] = map->attnums[pkattnum[j] - 1];
+			}
+			else
+				mapped_pkattnum = pkattnum;
+
+			/* do the deed */
+			partIndexId = index_get_partition(partRel, indexOid);
+			if (!OidIsValid(partIndexId))
+				elog(ERROR, "index for %u not found in partition %s",
+					 indexOid, RelationGetRelationName(partRel));
+			addFkRecurseReferenced(wqueue, fkconstraint, rel, partRel,
+								   partIndexId, constrOid, numfks,
+								   mapped_pkattnum, fkattnum,
+								   pfeqoperators, ppeqoperators, ffeqoperators,
+								   numfkdelsetcols, fkdelsetcols,
+								   old_check_ok,
+								   deleteTriggerOid, updateTriggerOid);
+
+			/* Done -- clean up (but keep the lock) */
+			table_close(partRel, NoLock);
+			if (map)
+			{
+				pfree(mapped_pkattnum);
+				free_attrmap(map);
+			}
+		}
+	}
+
+	return address;
+}
+
+/*
+ * addFkRecurseReferencing
+ *		subroutine for ATAddForeignKeyConstraint and CloneFkReferencing
+ *
+ * If the referencing relation is a plain relation, create the necessary check
+ * triggers that implement the constraint, and set up for Phase 3 constraint
+ * verification.  If the referencing relation is a partitioned table, then
+ * we create a pg_constraint row for it and recurse on this routine for each
+ * partition.
+ *
+ * We assume that the referenced relation is locked against concurrent
+ * deletions.  If it's a partitioned relation, every partition must be so
+ * locked.
+ *
+ * wqueue is the ALTER TABLE work queue; can be NULL when not running as part
+ * of an ALTER TABLE sequence.
+ * fkconstraint is the constraint being added.
+ * rel is the referencing relation; might be a partition, if recursing.
+ * pkrel is the root referenced relation.
+ * indexOid is the OID of the index (on pkrel) implementing this constraint.
+ * parentConstr is the OID of the parent constraint (there is always one).
+ * numfks is the number of columns in the foreign key
+ * pkattnum is the attnum array of referenced attributes.
+ * fkattnum is the attnum array of referencing attributes.
+ * pf/pp/ffeqoperators are OID array of operators between columns.
+ * numfkdelsetcols is the number of columns in the ON DELETE SET NULL/DEFAULT
+ *      (...) clause
+ * fkdelsetcols is the attnum array of the columns in the ON DELETE SET
+ *      NULL/DEFAULT clause
+ * old_check_ok signals that this constraint replaces an existing one that
+ *		was already validated (thus this one doesn't need validation).
+ * lockmode is the lockmode to acquire on partitions when recursing.
+ * parentInsTrigger and parentUpdTrigger, when being recursively called on
+ * a partition, are the OIDs of the parent check triggers for INSERT and
+ * UPDATE respectively.
+ */
+static void
+addFkRecurseReferencing(List **wqueue, Constraint *fkconstraint, Relation rel,
+						Relation pkrel, Oid indexOid, Oid parentConstr,
+						int numfks, int16 *pkattnum, int16 *fkattnum,
+						Oid *pfeqoperators, Oid *ppeqoperators, Oid *ffeqoperators,
+						int numfkdelsetcols, int16 *fkdelsetcols,
+						bool old_check_ok, LOCKMODE lockmode,
+						Oid parentInsTrigger, Oid parentUpdTrigger)
+{
+	Oid			insertTriggerOid,
+				updateTriggerOid;
+
+	AssertArg(OidIsValid(parentConstr));
+
+	if (rel->rd_rel->relkind == RELKIND_FOREIGN_TABLE)
+		ereport(ERROR,
+				(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+				 errmsg("foreign key constraints are not supported on foreign tables")));
+
+	/*
+	 * Add the check triggers to it and, if necessary, schedule it to be
+	 * checked in Phase 3.
+	 *
+	 * If the relation is partitioned, drill down to do it to its partitions.
+	 */
+	createForeignKeyCheckTriggers(RelationGetRelid(rel),
+								  RelationGetRelid(pkrel),
+								  fkconstraint,
+								  parentConstr,
+								  indexOid,
+								  parentInsTrigger, parentUpdTrigger,
+								  &insertTriggerOid, &updateTriggerOid);
+
+	if (rel->rd_rel->relkind == RELKIND_RELATION)
+	{
+		/*
+		 * Tell Phase 3 to check that the constraint is satisfied by existing
+		 * rows. We can skip this during table creation, when requested
+		 * explicitly by specifying NOT VALID in an ADD FOREIGN KEY command,
+		 * and when we're recreating a constraint following a SET DATA TYPE
+		 * operation that did not impugn its validity.
+		 */
+		if (wqueue && !old_check_ok && !fkconstraint->skip_validation)
+		{
+			NewConstraint *newcon;
+			AlteredTableInfo *tab;
+
+			tab = ATGetQueueEntry(wqueue, rel);
+
+			newcon = (NewConstraint *) palloc0(sizeof(NewConstraint));
+			newcon->name = get_constraint_name(parentConstr);
+			newcon->contype = CONSTR_FOREIGN;
+			newcon->refrelid = RelationGetRelid(pkrel);
+			newcon->refindid = indexOid;
+			newcon->conid = parentConstr;
+			newcon->qual = (Node *) fkconstraint;
+
+			tab->constraints = lappend(tab->constraints, newcon);
+		}
+	}
+	else if (rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
+	{
+		PartitionDesc pd = RelationGetPartitionDesc(rel, true);
+		Relation	trigrel;
+
+		/*
+		 * Triggers of the foreign keys will be manipulated a bunch of times
+		 * in the loop below.  To avoid repeatedly opening/closing the trigger
+		 * catalog relation, we open it here and pass it to the subroutines
+		 * called below.
+		 */
+		trigrel = table_open(TriggerRelationId, RowExclusiveLock);
+
+		/*
+		 * Recurse to take appropriate action on each partition; either we
+		 * find an existing constraint to reparent to ours, or we create a new
+		 * one.
+		 */
+		for (int i = 0; i < pd->nparts; i++)
+		{
+			Oid			partitionId = pd->oids[i];
+			Relation	partition = table_open(partitionId, lockmode);
+			List	   *partFKs;
+			AttrMap    *attmap;
+			AttrNumber	mapped_fkattnum[INDEX_MAX_KEYS];
+			bool		attached;
+			char	   *conname;
+			Oid			constrOid;
+			ObjectAddress address,
+						referenced;
+			ListCell   *cell;
+
+			CheckTableNotInUse(partition, "ALTER TABLE");
+
+			attmap = build_attrmap_by_name(RelationGetDescr(partition),
+										   RelationGetDescr(rel));
+			for (int j = 0; j < numfks; j++)
+				mapped_fkattnum[j] = attmap->attnums[fkattnum[j] - 1];
+
+			/* Check whether an existing constraint can be repurposed */
+			partFKs = copyObject(RelationGetFKeyList(partition));
+			attached = false;
+			foreach(cell, partFKs)
+			{
+				ForeignKeyCacheInfo *fk;
+
+				fk = lfirst_node(ForeignKeyCacheInfo, cell);
+				if (tryAttachPartitionForeignKey(fk,
+												 partitionId,
+												 parentConstr,
+												 numfks,
+												 mapped_fkattnum,
+												 pkattnum,
+												 pfeqoperators,
+												 insertTriggerOid,
+												 updateTriggerOid,
+												 trigrel))
+				{
+					attached = true;
+					break;
+				}
+			}
+			if (attached)
+			{
+				table_close(partition, NoLock);
+				continue;
+			}
+
+			/*
+			 * No luck finding a good constraint to reuse; create our own.
+			 */
+			if (ConstraintNameIsUsed(CONSTRAINT_RELATION,
+									 RelationGetRelid(partition),
+									 fkconstraint->conname))
+				conname = ChooseConstraintName(RelationGetRelationName(partition),
+											   ChooseForeignKeyConstraintNameAddition(fkconstraint->fk_attrs),
+											   "fkey",
+											   RelationGetNamespace(partition), NIL);
+			else
+				conname = fkconstraint->conname;
+			constrOid =
+				CreateConstraintEntry(conname,
+									  RelationGetNamespace(partition),
+									  CONSTRAINT_FOREIGN,
+									  fkconstraint->deferrable,
+									  fkconstraint->initdeferred,
+									  fkconstraint->initially_valid,
+									  parentConstr,
+									  partitionId,
+									  mapped_fkattnum,
+									  numfks,
+									  numfks,
+									  InvalidOid,
+									  indexOid,
+									  RelationGetRelid(pkrel),
+									  pkattnum,
+									  pfeqoperators,
+									  ppeqoperators,
+									  ffeqoperators,
+									  numfks,
+									  fkconstraint->fk_upd_action,
+									  fkconstraint->fk_del_action,
+									  fkdelsetcols,
+									  numfkdelsetcols,
+									  fkconstraint->fk_matchtype,
+									  NULL,
+									  NULL,
+									  NULL,
+									  false,
+									  1,
+									  false,
+									  false);
+
+			/*
+			 * Give this constraint partition-type dependencies on the parent
+			 * constraint as well as the table.
+			 */
+			ObjectAddressSet(address, ConstraintRelationId, constrOid);
+			ObjectAddressSet(referenced, ConstraintRelationId, parentConstr);
+			recordDependencyOn(&address, &referenced, DEPENDENCY_PARTITION_PRI);
+			ObjectAddressSet(referenced, RelationRelationId, partitionId);
+			recordDependencyOn(&address, &referenced, DEPENDENCY_PARTITION_SEC);
+
+			/* Make all this visible before recursing */
+			CommandCounterIncrement();
+
+			/* call ourselves to finalize the creation and we're done */
+			addFkRecurseReferencing(wqueue, fkconstraint, partition, pkrel,
+									indexOid,
+									constrOid,
+									numfks,
+									pkattnum,
+									mapped_fkattnum,
+									pfeqoperators,
+									ppeqoperators,
+									ffeqoperators,
+									numfkdelsetcols,
+									fkdelsetcols,
+									old_check_ok,
+									lockmode,
+									insertTriggerOid,
+									updateTriggerOid);
+
+			table_close(partition, NoLock);
+		}
+
+		table_close(trigrel, RowExclusiveLock);
+	}
+}
+
+/*
+ * CloneForeignKeyConstraints
+ *		Clone foreign keys from a partitioned table to a newly acquired
+ *		partition.
+ *
+ * partitionRel is a partition of parentRel, so we can be certain that it has
+ * the same columns with the same datatypes.  The columns may be in different
+ * order, though.
+ *
+ * wqueue must be passed to set up phase 3 constraint checking, unless the
+ * referencing-side partition is known to be empty (such as in CREATE TABLE /
+ * PARTITION OF).
+ */
+static void
+CloneForeignKeyConstraints(List **wqueue, Relation parentRel,
+						   Relation partitionRel)
+{
+	/* This only works for declarative partitioning */
+	Assert(parentRel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE);
+
+	/*
+	 * Clone constraints for which the parent is on the referenced side.
+	 */
+	CloneFkReferenced(parentRel, partitionRel);
+
+	/*
+	 * Now clone constraints where the parent is on the referencing side.
+	 */
+	CloneFkReferencing(wqueue, parentRel, partitionRel);
+}
+
+/*
+ * CloneFkReferenced
+ *		Subroutine for CloneForeignKeyConstraints
+ *
+ * Find all the FKs that have the parent relation on the referenced side;
+ * clone those constraints to the given partition.  This is to be called
+ * when the partition is being created or attached.
+ *
+ * This ignores self-referencing FKs; those are handled by CloneFkReferencing.
+ *
+ * This recurses to partitions, if the relation being attached is partitioned.
+ * Recursion is done by calling addFkRecurseReferenced.
+ */
+static void
+CloneFkReferenced(Relation parentRel, Relation partitionRel)
+{
+	Relation	pg_constraint;
+	AttrMap    *attmap;
+	ListCell   *cell;
+	SysScanDesc scan;
+	ScanKeyData key[2];
+	HeapTuple	tuple;
+	List	   *clone = NIL;
+	Relation	trigrel;
+
+	/*
+	 * Search for any constraints where this partition's parent is in the
+	 * referenced side.  However, we must not clone any constraint whose
+	 * parent constraint is also going to be cloned, to avoid duplicates.  So
+	 * do it in two steps: first construct the list of constraints to clone,
+	 * then go over that list cloning those whose parents are not in the list.
+	 * (We must not rely on the parent being seen first, since the catalog
+	 * scan could return children first.)
+	 */
+	pg_constraint = table_open(ConstraintRelationId, RowShareLock);
+	ScanKeyInit(&key[0],
+				Anum_pg_constraint_confrelid, BTEqualStrategyNumber,
+				F_OIDEQ, ObjectIdGetDatum(RelationGetRelid(parentRel)));
+	ScanKeyInit(&key[1],
+				Anum_pg_constraint_contype, BTEqualStrategyNumber,
+				F_CHAREQ, CharGetDatum(CONSTRAINT_FOREIGN));
+	/* This is a seqscan, as we don't have a usable index ... */
+	scan = systable_beginscan(pg_constraint, InvalidOid, true,
+							  NULL, 2, key);
+	while ((tuple = systable_getnext(scan)) != NULL)
+	{
+		Form_pg_constraint constrForm = (Form_pg_constraint) GETSTRUCT(tuple);
+
+		clone = lappend_oid(clone, constrForm->oid);
+	}
+	systable_endscan(scan);
+	table_close(pg_constraint, RowShareLock);
+
+	/*
+	 * Triggers of the foreign keys will be manipulated a bunch of times in
+	 * the loop below.  To avoid repeatedly opening/closing the trigger
+	 * catalog relation, we open it here and pass it to the subroutines called
+	 * below.
+	 */
+	trigrel = table_open(TriggerRelationId, RowExclusiveLock);
+
+	attmap = build_attrmap_by_name(RelationGetDescr(partitionRel),
+								   RelationGetDescr(parentRel));
+	foreach(cell, clone)
+	{
+		Oid			constrOid = lfirst_oid(cell);
+		Form_pg_constraint constrForm;
+		Relation	fkRel;
+		Oid			indexOid;
+		Oid			partIndexId;
+		int			numfks;
+		AttrNumber	conkey[INDEX_MAX_KEYS];
+		AttrNumber	mapped_confkey[INDEX_MAX_KEYS];
+		AttrNumber	confkey[INDEX_MAX_KEYS];
+		Oid			conpfeqop[INDEX_MAX_KEYS];
+		Oid			conppeqop[INDEX_MAX_KEYS];
+		Oid			conffeqop[INDEX_MAX_KEYS];
+		int			numfkdelsetcols;
+		AttrNumber	confdelsetcols[INDEX_MAX_KEYS];
+		Constraint *fkconstraint;
+		Oid			deleteTriggerOid,
+					updateTriggerOid;
+
+		tuple = SearchSysCache1(CONSTROID, constrOid);
+		if (!HeapTupleIsValid(tuple))
+			elog(ERROR, "cache lookup failed for constraint %u", constrOid);
+		constrForm = (Form_pg_constraint) GETSTRUCT(tuple);
+
+		/*
+		 * As explained above: don't try to clone a constraint for which we're
+		 * going to clone the parent.
+		 */
+		if (list_member_oid(clone, constrForm->conparentid))
+		{
+			ReleaseSysCache(tuple);
+			continue;
+		}
+
+		/*
+		 * Don't clone self-referencing foreign keys, which can be in the
+		 * partitioned table or in the partition-to-be.
+		 */
+		if (constrForm->conrelid == RelationGetRelid(parentRel) ||
+			constrForm->conrelid == RelationGetRelid(partitionRel))
+		{
+			ReleaseSysCache(tuple);
+			continue;
+		}
+
+		/*
+		 * Because we're only expanding the key space at the referenced side,
+		 * we don't need to prevent any operation in the referencing table, so
+		 * AccessShareLock suffices (assumes that dropping the constraint
+		 * acquires AEL).
+		 */
+		fkRel = table_open(constrForm->conrelid, AccessShareLock);
+
+		indexOid = constrForm->conindid;
+		DeconstructFkConstraintRow(tuple,
+								   &numfks,
+								   conkey,
+								   confkey,
+								   conpfeqop,
+								   conppeqop,
+								   conffeqop,
+								   &numfkdelsetcols,
+								   confdelsetcols);
+
+		for (int i = 0; i < numfks; i++)
+			mapped_confkey[i] = attmap->attnums[confkey[i] - 1];
+
+		fkconstraint = makeNode(Constraint);
+		fkconstraint->contype = CONSTRAINT_FOREIGN;
+		fkconstraint->conname = NameStr(constrForm->conname);
+		fkconstraint->deferrable = constrForm->condeferrable;
+		fkconstraint->initdeferred = constrForm->condeferred;
+		fkconstraint->location = -1;
+		fkconstraint->pktable = NULL;
+		/* ->fk_attrs determined below */
+		fkconstraint->pk_attrs = NIL;
+		fkconstraint->fk_matchtype = constrForm->confmatchtype;
+		fkconstraint->fk_upd_action = constrForm->confupdtype;
+		fkconstraint->fk_del_action = constrForm->confdeltype;
+		fkconstraint->fk_del_set_cols = NIL;
+		fkconstraint->old_conpfeqop = NIL;
+		fkconstraint->old_pktable_oid = InvalidOid;
+		fkconstraint->skip_validation = false;
+		fkconstraint->initially_valid = true;
+
+		/* set up colnames that are used to generate the constraint name */
+		for (int i = 0; i < numfks; i++)
+		{
+			Form_pg_attribute att;
+
+			att = TupleDescAttr(RelationGetDescr(fkRel),
+								conkey[i] - 1);
+			fkconstraint->fk_attrs = lappend(fkconstraint->fk_attrs,
+											 makeString(NameStr(att->attname)));
+		}
+
+		/*
+		 * Add the new foreign key constraint pointing to the new partition.
+		 * Because this new partition appears in the referenced side of the
+		 * constraint, we don't need to set up for Phase 3 check.
+		 */
+		partIndexId = index_get_partition(partitionRel, indexOid);
+		if (!OidIsValid(partIndexId))
+			elog(ERROR, "index for %u not found in partition %s",
+				 indexOid, RelationGetRelationName(partitionRel));
+
+		/*
+		 * Get the "action" triggers belonging to the constraint to pass as
+		 * parent OIDs for similar triggers that will be created on the
+		 * partition in addFkRecurseReferenced().
+		 */
+		GetForeignKeyActionTriggers(trigrel, constrOid,
+									constrForm->confrelid, constrForm->conrelid,
+									&deleteTriggerOid, &updateTriggerOid);
+
+		addFkRecurseReferenced(NULL,
+							   fkconstraint,
+							   fkRel,
+							   partitionRel,
+							   partIndexId,
+							   constrOid,
+							   numfks,
+							   mapped_confkey,
+							   conkey,
+							   conpfeqop,
+							   conppeqop,
+							   conffeqop,
+							   numfkdelsetcols,
+							   confdelsetcols,
+							   true,
+							   deleteTriggerOid,
+							   updateTriggerOid);
+
+		table_close(fkRel, NoLock);
+		ReleaseSysCache(tuple);
+	}
+
+	table_close(trigrel, RowExclusiveLock);
+}
+
+/*
+ * CloneFkReferencing
+ *		Subroutine for CloneForeignKeyConstraints
+ *
+ * For each FK constraint of the parent relation in the given list, find an
+ * equivalent constraint in its partition relation that can be reparented;
+ * if one cannot be found, create a new constraint in the partition as its
+ * child.
+ *
+ * If wqueue is given, it is used to set up phase-3 verification for each
+ * cloned constraint; if omitted, we assume that such verification is not
+ * needed (example: the partition is being created anew).
+ */
+static void
+CloneFkReferencing(List **wqueue, Relation parentRel, Relation partRel)
+{
+	AttrMap    *attmap;
+	List	   *partFKs;
+	List	   *clone = NIL;
+	ListCell   *cell;
+	Relation	trigrel;
+
+	/* obtain a list of constraints that we need to clone */
+	foreach(cell, RelationGetFKeyList(parentRel))
+	{
+		ForeignKeyCacheInfo *fk = lfirst(cell);
+
+		clone = lappend_oid(clone, fk->conoid);
+	}
+
+	/*
+	 * Silently do nothing if there's nothing to do.  In particular, this
+	 * avoids throwing a spurious error for foreign tables.
+	 */
+	if (clone == NIL)
+		return;
+
+	if (partRel->rd_rel->relkind == RELKIND_FOREIGN_TABLE)
+		ereport(ERROR,
+				(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+				 errmsg("foreign key constraints are not supported on foreign tables")));
+
+	/*
+	 * Triggers of the foreign keys will be manipulated a bunch of times in
+	 * the loop below.  To avoid repeatedly opening/closing the trigger
+	 * catalog relation, we open it here and pass it to the subroutines called
+	 * below.
+	 */
+	trigrel = table_open(TriggerRelationId, RowExclusiveLock);
+
+	/*
+	 * The constraint key may differ, if the columns in the partition are
+	 * different.  This map is used to convert them.
+	 */
+	attmap = build_attrmap_by_name(RelationGetDescr(partRel),
+								   RelationGetDescr(parentRel));
+
+	partFKs = copyObject(RelationGetFKeyList(partRel));
+
+	foreach(cell, clone)
+	{
+		Oid			parentConstrOid = lfirst_oid(cell);
+		Form_pg_constraint constrForm;
+		Relation	pkrel;
+		HeapTuple	tuple;
+		int			numfks;
+		AttrNumber	conkey[INDEX_MAX_KEYS];
+		AttrNumber	mapped_conkey[INDEX_MAX_KEYS];
+		AttrNumber	confkey[INDEX_MAX_KEYS];
+		Oid			conpfeqop[INDEX_MAX_KEYS];
+		Oid			conppeqop[INDEX_MAX_KEYS];
+		Oid			conffeqop[INDEX_MAX_KEYS];
+		int			numfkdelsetcols;
+		AttrNumber	confdelsetcols[INDEX_MAX_KEYS];
+		Constraint *fkconstraint;
+		bool		attached;
+		Oid			indexOid;
+		Oid			constrOid;
+		ObjectAddress address,
+					referenced;
+		ListCell   *cell;
+		Oid			insertTriggerOid,
+					updateTriggerOid;
+
+		tuple = SearchSysCache1(CONSTROID, parentConstrOid);
+		if (!HeapTupleIsValid(tuple))
+			elog(ERROR, "cache lookup failed for constraint %u",
+				 parentConstrOid);
+		constrForm = (Form_pg_constraint) GETSTRUCT(tuple);
+
+		/* Don't clone constraints whose parents are being cloned */
+		if (list_member_oid(clone, constrForm->conparentid))
+		{
+			ReleaseSysCache(tuple);
+			continue;
+		}
+
+		/*
+		 * Need to prevent concurrent deletions.  If pkrel is a partitioned
+		 * relation, that means to lock all partitions.
+		 */
+		pkrel = table_open(constrForm->confrelid, ShareRowExclusiveLock);
+		if (pkrel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
+			(void) find_all_inheritors(RelationGetRelid(pkrel),
+									   ShareRowExclusiveLock, NULL);
+
+		DeconstructFkConstraintRow(tuple, &numfks, conkey, confkey,
+								   conpfeqop, conppeqop, conffeqop,
+								   &numfkdelsetcols, confdelsetcols);
+		for (int i = 0; i < numfks; i++)
+			mapped_conkey[i] = attmap->attnums[conkey[i] - 1];
+
+		/*
+		 * Get the "check" triggers belonging to the constraint to pass as
+		 * parent OIDs for similar triggers that will be created on the
+		 * partition in addFkRecurseReferencing().  They are also passed to
+		 * tryAttachPartitionForeignKey() below to simply assign as parents to
+		 * the partition's existing "check" triggers, that is, if the
+		 * corresponding constraints is deemed attachable to the parent
+		 * constraint.
+		 */
+		GetForeignKeyCheckTriggers(trigrel, constrForm->oid,
+								   constrForm->confrelid, constrForm->conrelid,
+								   &insertTriggerOid, &updateTriggerOid);
+
+		/*
+		 * Before creating a new constraint, see whether any existing FKs are
+		 * fit for the purpose.  If one is, attach the parent constraint to
+		 * it, and don't clone anything.  This way we avoid the expensive
+		 * verification step and don't end up with a duplicate FK, and we
+		 * don't need to recurse to partitions for this constraint.
+		 */
+		attached = false;
+		foreach(cell, partFKs)
+		{
+			ForeignKeyCacheInfo *fk = lfirst_node(ForeignKeyCacheInfo, cell);
+
+			if (tryAttachPartitionForeignKey(fk,
+											 RelationGetRelid(partRel),
+											 parentConstrOid,
+											 numfks,
+											 mapped_conkey,
+											 confkey,
+											 conpfeqop,
+											 insertTriggerOid,
+											 updateTriggerOid,
+											 trigrel))
+			{
+				attached = true;
+				table_close(pkrel, NoLock);
+				break;
+			}
+		}
+		if (attached)
+		{
+			ReleaseSysCache(tuple);
+			continue;
+		}
+
+		/* No dice.  Set up to create our own constraint */
+		fkconstraint = makeNode(Constraint);
+		fkconstraint->contype = CONSTRAINT_FOREIGN;
+		/* ->conname determined below */
+		fkconstraint->deferrable = constrForm->condeferrable;
+		fkconstraint->initdeferred = constrForm->condeferred;
+		fkconstraint->location = -1;
+		fkconstraint->pktable = NULL;
+		/* ->fk_attrs determined below */
+		fkconstraint->pk_attrs = NIL;
+		fkconstraint->fk_matchtype = constrForm->confmatchtype;
+		fkconstraint->fk_upd_action = constrForm->confupdtype;
+		fkconstraint->fk_del_action = constrForm->confdeltype;
+		fkconstraint->fk_del_set_cols = NIL;
+		fkconstraint->old_conpfeqop = NIL;
+		fkconstraint->old_pktable_oid = InvalidOid;
+		fkconstraint->skip_validation = false;
+		fkconstraint->initially_valid = true;
+		for (int i = 0; i < numfks; i++)
+		{
+			Form_pg_attribute att;
+
+			att = TupleDescAttr(RelationGetDescr(partRel),
+								mapped_conkey[i] - 1);
+			fkconstraint->fk_attrs = lappend(fkconstraint->fk_attrs,
+											 makeString(NameStr(att->attname)));
+		}
+		if (ConstraintNameIsUsed(CONSTRAINT_RELATION,
+								 RelationGetRelid(partRel),
+								 NameStr(constrForm->conname)))
+			fkconstraint->conname =
+				ChooseConstraintName(RelationGetRelationName(partRel),
+									 ChooseForeignKeyConstraintNameAddition(fkconstraint->fk_attrs),
+									 "fkey",
+									 RelationGetNamespace(partRel), NIL);
+		else
+			fkconstraint->conname = pstrdup(NameStr(constrForm->conname));
+
+		indexOid = constrForm->conindid;
+		constrOid =
+			CreateConstraintEntry(fkconstraint->conname,
+								  constrForm->connamespace,
+								  CONSTRAINT_FOREIGN,
+								  fkconstraint->deferrable,
+								  fkconstraint->initdeferred,
+								  constrForm->convalidated,
+								  parentConstrOid,
+								  RelationGetRelid(partRel),
+								  mapped_conkey,
+								  numfks,
+								  numfks,
+								  InvalidOid,	/* not a domain constraint */
+								  indexOid,
+								  constrForm->confrelid,	/* same foreign rel */
+								  confkey,
+								  conpfeqop,
+								  conppeqop,
+								  conffeqop,
+								  numfks,
+								  fkconstraint->fk_upd_action,
+								  fkconstraint->fk_del_action,
+								  confdelsetcols,
+								  numfkdelsetcols,
+								  fkconstraint->fk_matchtype,
+								  NULL,
+								  NULL,
+								  NULL,
+								  false,	/* islocal */
+								  1,	/* inhcount */
+								  false,	/* conNoInherit */
+								  true);
+
+		/* Set up partition dependencies for the new constraint */
+		ObjectAddressSet(address, ConstraintRelationId, constrOid);
+		ObjectAddressSet(referenced, ConstraintRelationId, parentConstrOid);
+		recordDependencyOn(&address, &referenced, DEPENDENCY_PARTITION_PRI);
+		ObjectAddressSet(referenced, RelationRelationId,
+						 RelationGetRelid(partRel));
+		recordDependencyOn(&address, &referenced, DEPENDENCY_PARTITION_SEC);
+
+		/* Done with the cloned constraint's tuple */
+		ReleaseSysCache(tuple);
+
+		/* Make all this visible before recursing */
+		CommandCounterIncrement();
+
+		addFkRecurseReferencing(wqueue,
+								fkconstraint,
+								partRel,
+								pkrel,
+								indexOid,
+								constrOid,
+								numfks,
+								confkey,
+								mapped_conkey,
+								conpfeqop,
+								conppeqop,
+								conffeqop,
+								numfkdelsetcols,
+								confdelsetcols,
+								false,	/* no old check exists */
+								AccessExclusiveLock,
+								insertTriggerOid,
+								updateTriggerOid);
+		table_close(pkrel, NoLock);
+	}
+
+	table_close(trigrel, RowExclusiveLock);
+}
+
+/*
+ * When the parent of a partition receives [the referencing side of] a foreign
+ * key, we must propagate that foreign key to the partition.  However, the
+ * partition might already have an equivalent foreign key; this routine
+ * compares the given ForeignKeyCacheInfo (in the partition) to the FK defined
+ * by the other parameters.  If they are equivalent, create the link between
+ * the two constraints and return true.
+ *
+ * If the given FK does not match the one defined by rest of the params,
+ * return false.
+ */
+static bool
+tryAttachPartitionForeignKey(ForeignKeyCacheInfo *fk,
+							 Oid partRelid,
+							 Oid parentConstrOid,
+							 int numfks,
+							 AttrNumber *mapped_conkey,
+							 AttrNumber *confkey,
+							 Oid *conpfeqop,
+							 Oid parentInsTrigger,
+							 Oid parentUpdTrigger,
+							 Relation trigrel)
+{
+	HeapTuple	parentConstrTup;
+	Form_pg_constraint parentConstr;
+	HeapTuple	partcontup;
+	Form_pg_constraint partConstr;
+	ScanKeyData key;
+	SysScanDesc scan;
+	HeapTuple	trigtup;
+	Oid			insertTriggerOid,
+				updateTriggerOid;
+
+	parentConstrTup = SearchSysCache1(CONSTROID,
+									  ObjectIdGetDatum(parentConstrOid));
+	if (!HeapTupleIsValid(parentConstrTup))
+		elog(ERROR, "cache lookup failed for constraint %u", parentConstrOid);
+	parentConstr = (Form_pg_constraint) GETSTRUCT(parentConstrTup);
+
+	/*
+	 * Do some quick & easy initial checks.  If any of these fail, we cannot
+	 * use this constraint.
+	 */
+	if (fk->confrelid != parentConstr->confrelid || fk->nkeys != numfks)
+	{
+		ReleaseSysCache(parentConstrTup);
+		return false;
+	}
+	for (int i = 0; i < numfks; i++)
+	{
+		if (fk->conkey[i] != mapped_conkey[i] ||
+			fk->confkey[i] != confkey[i] ||
+			fk->conpfeqop[i] != conpfeqop[i])
+		{
+			ReleaseSysCache(parentConstrTup);
+			return false;
+		}
+	}
+
+	/*
+	 * Looks good so far; do some more extensive checks.  Presumably the check
+	 * for 'convalidated' could be dropped, since we don't really care about
+	 * that, but let's be careful for now.
+	 */
+	partcontup = SearchSysCache1(CONSTROID,
+								 ObjectIdGetDatum(fk->conoid));
+	if (!HeapTupleIsValid(partcontup))
+		elog(ERROR, "cache lookup failed for constraint %u", fk->conoid);
+	partConstr = (Form_pg_constraint) GETSTRUCT(partcontup);
+	if (OidIsValid(partConstr->conparentid) ||
+		!partConstr->convalidated ||
+		partConstr->condeferrable != parentConstr->condeferrable ||
+		partConstr->condeferred != parentConstr->condeferred ||
+		partConstr->confupdtype != parentConstr->confupdtype ||
+		partConstr->confdeltype != parentConstr->confdeltype ||
+		partConstr->confmatchtype != parentConstr->confmatchtype)
+	{
+		ReleaseSysCache(parentConstrTup);
+		ReleaseSysCache(partcontup);
+		return false;
+	}
+
+	ReleaseSysCache(partcontup);
+	ReleaseSysCache(parentConstrTup);
+
+	/*
+	 * Looks good!  Attach this constraint.  The action triggers in the new
+	 * partition become redundant -- the parent table already has equivalent
+	 * ones, and those will be able to reach the partition.  Remove the ones
+	 * in the partition.  We identify them because they have our constraint
+	 * OID, as well as being on the referenced rel.
+	 */
+	ScanKeyInit(&key,
+				Anum_pg_trigger_tgconstraint,
+				BTEqualStrategyNumber, F_OIDEQ,
+				ObjectIdGetDatum(fk->conoid));
+	scan = systable_beginscan(trigrel, TriggerConstraintIndexId, true,
+							  NULL, 1, &key);
+	while ((trigtup = systable_getnext(scan)) != NULL)
+	{
+		Form_pg_trigger trgform = (Form_pg_trigger) GETSTRUCT(trigtup);
+		ObjectAddress trigger;
+
+		if (trgform->tgconstrrelid != fk->conrelid)
+			continue;
+		if (trgform->tgrelid != fk->confrelid)
+			continue;
+
+		/*
+		 * The constraint is originally set up to contain this trigger as an
+		 * implementation object, so there's a dependency record that links
+		 * the two; however, since the trigger is no longer needed, we remove
+		 * the dependency link in order to be able to drop the trigger while
+		 * keeping the constraint intact.
+		 */
+		deleteDependencyRecordsFor(TriggerRelationId,
+								   trgform->oid,
+								   false);
+		/* make dependency deletion visible to performDeletion */
+		CommandCounterIncrement();
+		ObjectAddressSet(trigger, TriggerRelationId,
+						 trgform->oid);
+		performDeletion(&trigger, DROP_RESTRICT, 0);
+		/* make trigger drop visible, in case the loop iterates */
+		CommandCounterIncrement();
+	}
+
+	systable_endscan(scan);
+
+	ConstraintSetParentConstraint(fk->conoid, parentConstrOid, partRelid);
+
+	/*
+	 * Like the constraint, attach partition's "check" triggers to the
+	 * corresponding parent triggers.
+	 */
+	GetForeignKeyCheckTriggers(trigrel,
+							   fk->conoid, fk->confrelid, fk->conrelid,
+							   &insertTriggerOid, &updateTriggerOid);
+	Assert(OidIsValid(insertTriggerOid) && OidIsValid(parentInsTrigger));
+	TriggerSetParentTrigger(trigrel, insertTriggerOid, parentInsTrigger,
+							partRelid);
+	Assert(OidIsValid(updateTriggerOid) && OidIsValid(parentUpdTrigger));
+	TriggerSetParentTrigger(trigrel, updateTriggerOid, parentUpdTrigger,
+							partRelid);
+
+	CommandCounterIncrement();
+	return true;
+}
+
+/*
+ * GetForeignKeyActionTriggers
+ * 		Returns delete and update "action" triggers of the given relation
+ * 		belonging to the given constraint
+ */
+static void
+GetForeignKeyActionTriggers(Relation trigrel,
+							Oid conoid, Oid confrelid, Oid conrelid,
+							Oid *deleteTriggerOid,
+							Oid *updateTriggerOid)
+{
+	ScanKeyData key;
+	SysScanDesc scan;
+	HeapTuple	trigtup;
+
+	*deleteTriggerOid = *updateTriggerOid = InvalidOid;
+	ScanKeyInit(&key,
+				Anum_pg_trigger_tgconstraint,
+				BTEqualStrategyNumber, F_OIDEQ,
+				ObjectIdGetDatum(conoid));
+
+	scan = systable_beginscan(trigrel, TriggerConstraintIndexId, true,
+							  NULL, 1, &key);
+	while ((trigtup = systable_getnext(scan)) != NULL)
+	{
+		Form_pg_trigger trgform = (Form_pg_trigger) GETSTRUCT(trigtup);
+
+		if (trgform->tgconstrrelid != conrelid)
+			continue;
+		if (trgform->tgrelid != confrelid)
+			continue;
+		/* Only ever look at "action" triggers on the PK side. */
+		if (RI_FKey_trigger_type(trgform->tgfoid) != RI_TRIGGER_PK)
+			continue;
+		if (TRIGGER_FOR_DELETE(trgform->tgtype))
+		{
+			Assert(*deleteTriggerOid == InvalidOid);
+			*deleteTriggerOid = trgform->oid;
+		}
+		else if (TRIGGER_FOR_UPDATE(trgform->tgtype))
+		{
+			Assert(*updateTriggerOid == InvalidOid);
+			*updateTriggerOid = trgform->oid;
+		}
+#ifndef USE_ASSERT_CHECKING
+		/* In an assert-enabled build, continue looking to find duplicates */
+		if (OidIsValid(*deleteTriggerOid) && OidIsValid(*updateTriggerOid))
+			break;
+#endif
+	}
+
+	if (!OidIsValid(*deleteTriggerOid))
+		elog(ERROR, "could not find ON DELETE action trigger of foreign key constraint %u",
+			 conoid);
+	if (!OidIsValid(*updateTriggerOid))
+		elog(ERROR, "could not find ON UPDATE action trigger of foreign key constraint %u",
+			 conoid);
+
+	systable_endscan(scan);
+}
+
+/*
+ * GetForeignKeyCheckTriggers
+ * 		Returns insert and update "check" triggers of the given relation
+ * 		belonging to the given constraint
+ */
+static void
+GetForeignKeyCheckTriggers(Relation trigrel,
+						   Oid conoid, Oid confrelid, Oid conrelid,
+						   Oid *insertTriggerOid,
+						   Oid *updateTriggerOid)
+{
+	ScanKeyData key;
+	SysScanDesc scan;
+	HeapTuple	trigtup;
+
+	*insertTriggerOid = *updateTriggerOid = InvalidOid;
+	ScanKeyInit(&key,
+				Anum_pg_trigger_tgconstraint,
+				BTEqualStrategyNumber, F_OIDEQ,
+				ObjectIdGetDatum(conoid));
+
+	scan = systable_beginscan(trigrel, TriggerConstraintIndexId, true,
+							  NULL, 1, &key);
+	while ((trigtup = systable_getnext(scan)) != NULL)
+	{
+		Form_pg_trigger trgform = (Form_pg_trigger) GETSTRUCT(trigtup);
+
+		if (trgform->tgconstrrelid != confrelid)
+			continue;
+		if (trgform->tgrelid != conrelid)
+			continue;
+		/* Only ever look at "check" triggers on the FK side. */
+		if (RI_FKey_trigger_type(trgform->tgfoid) != RI_TRIGGER_FK)
+			continue;
+		if (TRIGGER_FOR_INSERT(trgform->tgtype))
+		{
+			Assert(*insertTriggerOid == InvalidOid);
+			*insertTriggerOid = trgform->oid;
+		}
+		else if (TRIGGER_FOR_UPDATE(trgform->tgtype))
+		{
+			Assert(*updateTriggerOid == InvalidOid);
+			*updateTriggerOid = trgform->oid;
+		}
+#ifndef USE_ASSERT_CHECKING
+		/* In an assert-enabled build, continue looking to find duplicates. */
+		if (OidIsValid(*insertTriggerOid) && OidIsValid(*updateTriggerOid))
+			break;
+#endif
+	}
+
+	if (!OidIsValid(*insertTriggerOid))
+		elog(ERROR, "could not find ON INSERT check triggers of foreign key constraint %u",
+			 conoid);
+	if (!OidIsValid(*updateTriggerOid))
+		elog(ERROR, "could not find ON UPDATE check triggers of foreign key constraint %u",
+			 conoid);
+
+	systable_endscan(scan);
+}
+
+/*
+ * ALTER TABLE ALTER CONSTRAINT
+ *
+ * Update the attributes of a constraint.
+ *
+ * Currently only works for Foreign Key constraints.
+ *
+ * If the constraint is modified, returns its address; otherwise, return
+ * InvalidObjectAddress.
+ */
+static ObjectAddress
+ATExecAlterConstraint(Relation rel, AlterTableCmd *cmd, bool recurse,
+					  bool recursing, LOCKMODE lockmode)
+{
+	Constraint *cmdcon;
+	Relation	conrel;
+	Relation	tgrel;
+	SysScanDesc scan;
+	ScanKeyData skey[3];
+	HeapTuple	contuple;
+	Form_pg_constraint currcon;
+	ObjectAddress address;
+	List	   *otherrelids = NIL;
+	ListCell   *lc;
+
+	cmdcon = castNode(Constraint, cmd->def);
+
+	conrel = table_open(ConstraintRelationId, RowExclusiveLock);
+	tgrel = table_open(TriggerRelationId, RowExclusiveLock);
+
+	/*
+	 * Find and check the target constraint
+	 */
+	ScanKeyInit(&skey[0],
+				Anum_pg_constraint_conrelid,
+				BTEqualStrategyNumber, F_OIDEQ,
+				ObjectIdGetDatum(RelationGetRelid(rel)));
+	ScanKeyInit(&skey[1],
+				Anum_pg_constraint_contypid,
+				BTEqualStrategyNumber, F_OIDEQ,
+				ObjectIdGetDatum(InvalidOid));
+	ScanKeyInit(&skey[2],
+				Anum_pg_constraint_conname,
+				BTEqualStrategyNumber, F_NAMEEQ,
+				CStringGetDatum(cmdcon->conname));
+	scan = systable_beginscan(conrel, ConstraintRelidTypidNameIndexId,
+							  true, NULL, 3, skey);
+
+	/* There can be at most one matching row */
+	if (!HeapTupleIsValid(contuple = systable_getnext(scan)))
+		ereport(ERROR,
+				(errcode(ERRCODE_UNDEFINED_OBJECT),
+				 errmsg("constraint \"%s\" of relation \"%s\" does not exist",
+						cmdcon->conname, RelationGetRelationName(rel))));
+
+	currcon = (Form_pg_constraint) GETSTRUCT(contuple);
+	if (currcon->contype != CONSTRAINT_FOREIGN)
+		ereport(ERROR,
+				(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+				 errmsg("constraint \"%s\" of relation \"%s\" is not a foreign key constraint",
+						cmdcon->conname, RelationGetRelationName(rel))));
+
+	/*
+	 * If it's not the topmost constraint, raise an error.
+	 *
+	 * Altering a non-topmost constraint leaves some triggers untouched, since
+	 * they are not directly connected to this constraint; also, pg_dump would
+	 * ignore the deferrability status of the individual constraint, since it
+	 * only dumps topmost constraints.  Avoid these problems by refusing this
+	 * operation and telling the user to alter the parent constraint instead.
+	 */
+	if (OidIsValid(currcon->conparentid))
+	{
+		HeapTuple	tp;
+		Oid			parent = currcon->conparentid;
+		char	   *ancestorname = NULL;
+		char	   *ancestortable = NULL;
+
+		/* Loop to find the topmost constraint */
+		while (HeapTupleIsValid(tp = SearchSysCache1(CONSTROID, ObjectIdGetDatum(parent))))
+		{
+			Form_pg_constraint contup = (Form_pg_constraint) GETSTRUCT(tp);
+
+			/* If no parent, this is the constraint we want */
+			if (!OidIsValid(contup->conparentid))
+			{
+				ancestorname = pstrdup(NameStr(contup->conname));
+				ancestortable = get_rel_name(contup->conrelid);
+				ReleaseSysCache(tp);
+				break;
+			}
+
+			parent = contup->conparentid;
+			ReleaseSysCache(tp);
+		}
+
+		ereport(ERROR,
+				(errmsg("cannot alter constraint \"%s\" on relation \"%s\"",
+						cmdcon->conname, RelationGetRelationName(rel)),
+				 ancestorname && ancestortable ?
+				 errdetail("Constraint \"%s\" is derived from constraint \"%s\" of relation \"%s\".",
+						   cmdcon->conname, ancestorname, ancestortable) : 0,
+				 errhint("You may alter the constraint it derives from, instead.")));
+	}
+
+	/*
+	 * Do the actual catalog work.  We can skip changing if already in the
+	 * desired state, but not if a partitioned table: partitions need to be
+	 * processed regardless, in case they had the constraint locally changed.
+	 */
+	address = InvalidObjectAddress;
+	if (currcon->condeferrable != cmdcon->deferrable ||
+		currcon->condeferred != cmdcon->initdeferred ||
+		rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
+	{
+		if (ATExecAlterConstrRecurse(cmdcon, conrel, tgrel, rel, contuple,
+									 &otherrelids, lockmode))
+			ObjectAddressSet(address, ConstraintRelationId, currcon->oid);
+	}
+
+	/*
+	 * ATExecConstrRecurse already invalidated relcache for the relations
+	 * having the constraint itself; here we also invalidate for relations
+	 * that have any triggers that are part of the constraint.
+	 */
+	foreach(lc, otherrelids)
+		CacheInvalidateRelcacheByRelid(lfirst_oid(lc));
+
+	systable_endscan(scan);
+
+	table_close(tgrel, RowExclusiveLock);
+	table_close(conrel, RowExclusiveLock);
+
+	return address;
+}
+
+/*
+ * Recursive subroutine of ATExecAlterConstraint.  Returns true if the
+ * constraint is altered.
+ *
+ * *otherrelids is appended OIDs of relations containing affected triggers.
+ *
+ * Note that we must recurse even when the values are correct, in case
+ * indirect descendants have had their constraints altered locally.
+ * (This could be avoided if we forbade altering constraints in partitions
+ * but existing releases don't do that.)
+ */
+static bool
+ATExecAlterConstrRecurse(Constraint *cmdcon, Relation conrel, Relation tgrel,
+						 Relation rel, HeapTuple contuple, List **otherrelids,
+						 LOCKMODE lockmode)
+{
+	Form_pg_constraint currcon;
+	Oid			conoid;
+	Oid			refrelid;
+	bool		changed = false;
+
+	currcon = (Form_pg_constraint) GETSTRUCT(contuple);
+	conoid = currcon->oid;
+	refrelid = currcon->confrelid;
+
+	/*
+	 * Update pg_constraint with the flags from cmdcon.
+	 *
+	 * If called to modify a constraint that's already in the desired state,
+	 * silently do nothing.
+	 */
+	if (currcon->condeferrable != cmdcon->deferrable ||
+		currcon->condeferred != cmdcon->initdeferred)
+	{
+		HeapTuple	copyTuple;
+		Form_pg_constraint copy_con;
+		HeapTuple	tgtuple;
+		ScanKeyData tgkey;
+		SysScanDesc tgscan;
+
+		copyTuple = heap_copytuple(contuple);
+		copy_con = (Form_pg_constraint) GETSTRUCT(copyTuple);
+		copy_con->condeferrable = cmdcon->deferrable;
+		copy_con->condeferred = cmdcon->initdeferred;
+		CatalogTupleUpdate(conrel, &copyTuple->t_self, copyTuple);
+
+		InvokeObjectPostAlterHook(ConstraintRelationId,
+								  conoid, 0);
+
+		heap_freetuple(copyTuple);
+		changed = true;
+
+		/* Make new constraint flags visible to others */
+		CacheInvalidateRelcache(rel);
+
+		/*
+		 * Now we need to update the multiple entries in pg_trigger that
+		 * implement the constraint.
+		 */
+		ScanKeyInit(&tgkey,
+					Anum_pg_trigger_tgconstraint,
+					BTEqualStrategyNumber, F_OIDEQ,
+					ObjectIdGetDatum(conoid));
+		tgscan = systable_beginscan(tgrel, TriggerConstraintIndexId, true,
+									NULL, 1, &tgkey);
+		while (HeapTupleIsValid(tgtuple = systable_getnext(tgscan)))
+		{
+			Form_pg_trigger tgform = (Form_pg_trigger) GETSTRUCT(tgtuple);
+			Form_pg_trigger copy_tg;
+			HeapTuple	copyTuple;
+
+			/*
+			 * Remember OIDs of other relation(s) involved in FK constraint.
+			 * (Note: it's likely that we could skip forcing a relcache inval
+			 * for other rels that don't have a trigger whose properties
+			 * change, but let's be conservative.)
+			 */
+			if (tgform->tgrelid != RelationGetRelid(rel))
+				*otherrelids = list_append_unique_oid(*otherrelids,
+													  tgform->tgrelid);
+
+			/*
+			 * Update deferrability of RI_FKey_noaction_del,
+			 * RI_FKey_noaction_upd, RI_FKey_check_ins and RI_FKey_check_upd
+			 * triggers, but not others; see createForeignKeyActionTriggers
+			 * and CreateFKCheckTrigger.
+			 */
+			if (tgform->tgfoid != F_RI_FKEY_NOACTION_DEL &&
+				tgform->tgfoid != F_RI_FKEY_NOACTION_UPD &&
+				tgform->tgfoid != F_RI_FKEY_CHECK_INS &&
+				tgform->tgfoid != F_RI_FKEY_CHECK_UPD)
+				continue;
+
+			copyTuple = heap_copytuple(tgtuple);
+			copy_tg = (Form_pg_trigger) GETSTRUCT(copyTuple);
+
+			copy_tg->tgdeferrable = cmdcon->deferrable;
+			copy_tg->tginitdeferred = cmdcon->initdeferred;
+			CatalogTupleUpdate(tgrel, &copyTuple->t_self, copyTuple);
+
+			InvokeObjectPostAlterHook(TriggerRelationId, tgform->oid, 0);
+
+			heap_freetuple(copyTuple);
+		}
+
+		systable_endscan(tgscan);
+	}
+
+	/*
+	 * If the table at either end of the constraint is partitioned, we need to
+	 * recurse and handle every constraint that is a child of this one.
+	 *
+	 * (This assumes that the recurse flag is forcibly set for partitioned
+	 * tables, and not set for legacy inheritance, though we don't check for
+	 * that here.)
+	 */
+	if (rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE ||
+		get_rel_relkind(refrelid) == RELKIND_PARTITIONED_TABLE)
+	{
+		ScanKeyData pkey;
+		SysScanDesc pscan;
+		HeapTuple	childtup;
+
+		ScanKeyInit(&pkey,
+					Anum_pg_constraint_conparentid,
+					BTEqualStrategyNumber, F_OIDEQ,
+					ObjectIdGetDatum(conoid));
+
+		pscan = systable_beginscan(conrel, ConstraintParentIndexId,
+								   true, NULL, 1, &pkey);
+
+		while (HeapTupleIsValid(childtup = systable_getnext(pscan)))
+		{
+			Form_pg_constraint childcon = (Form_pg_constraint) GETSTRUCT(childtup);
+			Relation	childrel;
+
+			childrel = table_open(childcon->conrelid, lockmode);
+			ATExecAlterConstrRecurse(cmdcon, conrel, tgrel, childrel, childtup,
+									 otherrelids, lockmode);
+			table_close(childrel, NoLock);
+		}
+
+		systable_endscan(pscan);
+	}
+
+	return changed;
+}
+
+/*
+ * ALTER TABLE VALIDATE CONSTRAINT
+ *
+ * XXX The reason we handle recursion here rather than at Phase 1 is because
+ * there's no good way to skip recursing when handling foreign keys: there is
+ * no need to lock children in that case, yet we wouldn't be able to avoid
+ * doing so at that level.
+ *
+ * Return value is the address of the validated constraint.  If the constraint
+ * was already validated, InvalidObjectAddress is returned.
+ */
+static ObjectAddress
+ATExecValidateConstraint(List **wqueue, Relation rel, char *constrName,
+						 bool recurse, bool recursing, LOCKMODE lockmode)
+{
+	Relation	conrel;
+	SysScanDesc scan;
+	ScanKeyData skey[3];
+	HeapTuple	tuple;
+	Form_pg_constraint con;
+	ObjectAddress address;
+
+	conrel = table_open(ConstraintRelationId, RowExclusiveLock);
+
+	/*
+	 * Find and check the target constraint
+	 */
+	ScanKeyInit(&skey[0],
+				Anum_pg_constraint_conrelid,
+				BTEqualStrategyNumber, F_OIDEQ,
+				ObjectIdGetDatum(RelationGetRelid(rel)));
+	ScanKeyInit(&skey[1],
+				Anum_pg_constraint_contypid,
+				BTEqualStrategyNumber, F_OIDEQ,
+				ObjectIdGetDatum(InvalidOid));
+	ScanKeyInit(&skey[2],
+				Anum_pg_constraint_conname,
+				BTEqualStrategyNumber, F_NAMEEQ,
+				CStringGetDatum(constrName));
+	scan = systable_beginscan(conrel, ConstraintRelidTypidNameIndexId,
+							  true, NULL, 3, skey);
+
+	/* There can be at most one matching row */
+	if (!HeapTupleIsValid(tuple = systable_getnext(scan)))
+		ereport(ERROR,
+				(errcode(ERRCODE_UNDEFINED_OBJECT),
+				 errmsg("constraint \"%s\" of relation \"%s\" does not exist",
+						constrName, RelationGetRelationName(rel))));
+
+	con = (Form_pg_constraint) GETSTRUCT(tuple);
+	if (con->contype != CONSTRAINT_FOREIGN &&
+		con->contype != CONSTRAINT_CHECK)
+		ereport(ERROR,
+				(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+				 errmsg("constraint \"%s\" of relation \"%s\" is not a foreign key or check constraint",
+						constrName, RelationGetRelationName(rel))));
+
+	if (!con->convalidated)
+	{
+		AlteredTableInfo *tab;
+		HeapTuple	copyTuple;
+		Form_pg_constraint copy_con;
+
+		if (con->contype == CONSTRAINT_FOREIGN)
+		{
+			NewConstraint *newcon;
+			Constraint *fkconstraint;
+
+			/* Queue validation for phase 3 */
+			fkconstraint = makeNode(Constraint);
+			/* for now this is all we need */
+			fkconstraint->conname = constrName;
+
+			newcon = (NewConstraint *) palloc0(sizeof(NewConstraint));
+			newcon->name = constrName;
+			newcon->contype = CONSTR_FOREIGN;
+			newcon->refrelid = con->confrelid;
+			newcon->refindid = con->conindid;
+			newcon->conid = con->oid;
+			newcon->qual = (Node *) fkconstraint;
+
+			/* Find or create work queue entry for this table */
+			tab = ATGetQueueEntry(wqueue, rel);
+			tab->constraints = lappend(tab->constraints, newcon);
+
+			/*
+			 * We disallow creating invalid foreign keys to or from
+			 * partitioned tables, so ignoring the recursion bit is okay.
+			 */
+		}
+		else if (con->contype == CONSTRAINT_CHECK)
+		{
+			List	   *children = NIL;
+			ListCell   *child;
+			NewConstraint *newcon;
+			bool		isnull;
+			Datum		val;
+			char	   *conbin;
+
+			/*
+			 * If we're recursing, the parent has already done this, so skip
+			 * it.  Also, if the constraint is a NO INHERIT constraint, we
+			 * shouldn't try to look for it in the children.
+			 */
+			if (!recursing && !con->connoinherit)
+				children = find_all_inheritors(RelationGetRelid(rel),
+											   lockmode, NULL);
+
+			/*
+			 * For CHECK constraints, we must ensure that we only mark the
+			 * constraint as validated on the parent if it's already validated
+			 * on the children.
+			 *
+			 * We recurse before validating on the parent, to reduce risk of
+			 * deadlocks.
+			 */
+			foreach(child, children)
+			{
+				Oid			childoid = lfirst_oid(child);
+				Relation	childrel;
+
+				if (childoid == RelationGetRelid(rel))
+					continue;
+
+				/*
+				 * If we are told not to recurse, there had better not be any
+				 * child tables, because we can't mark the constraint on the
+				 * parent valid unless it is valid for all child tables.
+				 */
+				if (!recurse)
+					ereport(ERROR,
+							(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
+							 errmsg("constraint must be validated on child tables too")));
+
+				/* find_all_inheritors already got lock */
+				childrel = table_open(childoid, NoLock);
+
+				ATExecValidateConstraint(wqueue, childrel, constrName, false,
+										 true, lockmode);
+				table_close(childrel, NoLock);
+			}
+
+			/* Queue validation for phase 3 */
+			newcon = (NewConstraint *) palloc0(sizeof(NewConstraint));
+			newcon->name = constrName;
+			newcon->contype = CONSTR_CHECK;
+			newcon->refrelid = InvalidOid;
+			newcon->refindid = InvalidOid;
+			newcon->conid = con->oid;
+
+			val = SysCacheGetAttr(CONSTROID, tuple,
+								  Anum_pg_constraint_conbin, &isnull);
+			if (isnull)
+				elog(ERROR, "null conbin for constraint %u", con->oid);
+
+			conbin = TextDatumGetCString(val);
+			newcon->qual = (Node *) stringToNode(conbin);
+
+			/* Find or create work queue entry for this table */
+			tab = ATGetQueueEntry(wqueue, rel);
+			tab->constraints = lappend(tab->constraints, newcon);
+
+			/*
+			 * Invalidate relcache so that others see the new validated
+			 * constraint.
+			 */
+			CacheInvalidateRelcache(rel);
+		}
+
+		/*
+		 * Now update the catalog, while we have the door open.
+		 */
+		copyTuple = heap_copytuple(tuple);
+		copy_con = (Form_pg_constraint) GETSTRUCT(copyTuple);
+		copy_con->convalidated = true;
+		CatalogTupleUpdate(conrel, &copyTuple->t_self, copyTuple);
+
+		InvokeObjectPostAlterHook(ConstraintRelationId, con->oid, 0);
+
+		heap_freetuple(copyTuple);
+
+		ObjectAddressSet(address, ConstraintRelationId, con->oid);
+	}
+	else
+		address = InvalidObjectAddress; /* already validated */
+
+	systable_endscan(scan);
+
+	table_close(conrel, RowExclusiveLock);
+
+	return address;
+}
+
+
+/*
+ * transformColumnNameList - transform list of column names
+ *
+ * Lookup each name and return its attnum and, optionally, type OID
+ *
+ * Note: the name of this function suggests that it's general-purpose,
+ * but actually it's only used to look up names appearing in foreign-key
+ * clauses.  The error messages would need work to use it in other cases,
+ * and perhaps the validity checks as well.
+ */
+static int
+transformColumnNameList(Oid relId, List *colList,
+						int16 *attnums, Oid *atttypids)
+{
+	ListCell   *l;
+	int			attnum;
+
+	attnum = 0;
+	foreach(l, colList)
+	{
+		char	   *attname = strVal(lfirst(l));
+		HeapTuple	atttuple;
+		Form_pg_attribute attform;
+
+		atttuple = SearchSysCacheAttName(relId, attname);
+		if (!HeapTupleIsValid(atttuple))
+			ereport(ERROR,
+					(errcode(ERRCODE_UNDEFINED_COLUMN),
+					 errmsg("column \"%s\" referenced in foreign key constraint does not exist",
+							attname)));
+		attform = (Form_pg_attribute) GETSTRUCT(atttuple);
+		if (attform->attnum < 0)
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("system columns cannot be used in foreign keys")));
+		if (attnum >= INDEX_MAX_KEYS)
+			ereport(ERROR,
+					(errcode(ERRCODE_TOO_MANY_COLUMNS),
+					 errmsg("cannot have more than %d keys in a foreign key",
+							INDEX_MAX_KEYS)));
+		attnums[attnum] = attform->attnum;
+		if (atttypids != NULL)
+			atttypids[attnum] = attform->atttypid;
+		ReleaseSysCache(atttuple);
+		attnum++;
+	}
+
+	return attnum;
+}
+
+/*
+ * transformFkeyGetPrimaryKey -
+ *
+ *	Look up the names, attnums, and types of the primary key attributes
+ *	for the pkrel.  Also return the index OID and index opclasses of the
+ *	index supporting the primary key.
+ *
+ *	All parameters except pkrel are output parameters.  Also, the function
+ *	return value is the number of attributes in the primary key.
+ *
+ *	Used when the column list in the REFERENCES specification is omitted.
+ */
+static int
+transformFkeyGetPrimaryKey(Relation pkrel, Oid *indexOid,
+						   List **attnamelist,
+						   int16 *attnums, Oid *atttypids,
+						   Oid *opclasses)
+{
+	List	   *indexoidlist;
+	ListCell   *indexoidscan;
+	HeapTuple	indexTuple = NULL;
+	Form_pg_index indexStruct = NULL;
+	Datum		indclassDatum;
+	bool		isnull;
+	oidvector  *indclass;
+	int			i;
+
+	/*
+	 * Get the list of index OIDs for the table from the relcache, and look up
+	 * each one in the pg_index syscache until we find one marked primary key
+	 * (hopefully there isn't more than one such).  Insist it's valid, too.
+	 */
+	*indexOid = InvalidOid;
+
+	indexoidlist = RelationGetIndexList(pkrel);
+
+	foreach(indexoidscan, indexoidlist)
+	{
+		Oid			indexoid = lfirst_oid(indexoidscan);
+
+		indexTuple = SearchSysCache1(INDEXRELID, ObjectIdGetDatum(indexoid));
+		if (!HeapTupleIsValid(indexTuple))
+			elog(ERROR, "cache lookup failed for index %u", indexoid);
+		indexStruct = (Form_pg_index) GETSTRUCT(indexTuple);
+		if (indexStruct->indisprimary && indexStruct->indisvalid)
+		{
+			/*
+			 * Refuse to use a deferrable primary key.  This is per SQL spec,
+			 * and there would be a lot of interesting semantic problems if we
+			 * tried to allow it.
+			 */
+			if (!indexStruct->indimmediate)
+				ereport(ERROR,
+						(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+						 errmsg("cannot use a deferrable primary key for referenced table \"%s\"",
+								RelationGetRelationName(pkrel))));
+
+			*indexOid = indexoid;
+			break;
+		}
+		ReleaseSysCache(indexTuple);
+	}
+
+	list_free(indexoidlist);
+
+	/*
+	 * Check that we found it
+	 */
+	if (!OidIsValid(*indexOid))
+		ereport(ERROR,
+				(errcode(ERRCODE_UNDEFINED_OBJECT),
+				 errmsg("there is no primary key for referenced table \"%s\"",
+						RelationGetRelationName(pkrel))));
+
+	/* Must get indclass the hard way */
+	indclassDatum = SysCacheGetAttr(INDEXRELID, indexTuple,
+									Anum_pg_index_indclass, &isnull);
+	Assert(!isnull);
+	indclass = (oidvector *) DatumGetPointer(indclassDatum);
+
+	/*
+	 * Now build the list of PK attributes from the indkey definition (we
+	 * assume a primary key cannot have expressional elements)
+	 */
+	*attnamelist = NIL;
+	for (i = 0; i < indexStruct->indnkeyatts; i++)
+	{
+		int			pkattno = indexStruct->indkey.values[i];
+
+		attnums[i] = pkattno;
+		atttypids[i] = attnumTypeId(pkrel, pkattno);
+		opclasses[i] = indclass->values[i];
+		*attnamelist = lappend(*attnamelist,
+							   makeString(pstrdup(NameStr(*attnumAttName(pkrel, pkattno)))));
+	}
+
+	ReleaseSysCache(indexTuple);
+
+	return i;
+}
+
+/*
+ * transformFkeyCheckAttrs -
+ *
+ *	Make sure that the attributes of a referenced table belong to a unique
+ *	(or primary key) constraint.  Return the OID of the index supporting
+ *	the constraint, as well as the opclasses associated with the index
+ *	columns.
+ */
+static Oid
+transformFkeyCheckAttrs(Relation pkrel,
+						int numattrs, int16 *attnums,
+						Oid *opclasses) /* output parameter */
+{
+	Oid			indexoid = InvalidOid;
+	bool		found = false;
+	bool		found_deferrable = false;
+	List	   *indexoidlist;
+	ListCell   *indexoidscan;
+	int			i,
+				j;
+
+	/*
+	 * Reject duplicate appearances of columns in the referenced-columns list.
+	 * Such a case is forbidden by the SQL standard, and even if we thought it
+	 * useful to allow it, there would be ambiguity about how to match the
+	 * list to unique indexes (in particular, it'd be unclear which index
+	 * opclass goes with which FK column).
+	 */
+	for (i = 0; i < numattrs; i++)
+	{
+		for (j = i + 1; j < numattrs; j++)
+		{
+			if (attnums[i] == attnums[j])
+				ereport(ERROR,
+						(errcode(ERRCODE_INVALID_FOREIGN_KEY),
+						 errmsg("foreign key referenced-columns list must not contain duplicates")));
+		}
+	}
+
+	/*
+	 * Get the list of index OIDs for the table from the relcache, and look up
+	 * each one in the pg_index syscache, and match unique indexes to the list
+	 * of attnums we are given.
+	 */
+	indexoidlist = RelationGetIndexList(pkrel);
+
+	foreach(indexoidscan, indexoidlist)
+	{
+		HeapTuple	indexTuple;
+		Form_pg_index indexStruct;
+
+		indexoid = lfirst_oid(indexoidscan);
+		indexTuple = SearchSysCache1(INDEXRELID, ObjectIdGetDatum(indexoid));
+		if (!HeapTupleIsValid(indexTuple))
+			elog(ERROR, "cache lookup failed for index %u", indexoid);
+		indexStruct = (Form_pg_index) GETSTRUCT(indexTuple);
+
+		/*
+		 * Must have the right number of columns; must be unique and not a
+		 * partial index; forget it if there are any expressions, too. Invalid
+		 * indexes are out as well.
+		 */
+		if (indexStruct->indnkeyatts == numattrs &&
+			indexStruct->indisunique &&
+			indexStruct->indisvalid &&
+			heap_attisnull(indexTuple, Anum_pg_index_indpred, NULL) &&
+			heap_attisnull(indexTuple, Anum_pg_index_indexprs, NULL))
+		{
+			Datum		indclassDatum;
+			bool		isnull;
+			oidvector  *indclass;
+
+			/* Must get indclass the hard way */
+			indclassDatum = SysCacheGetAttr(INDEXRELID, indexTuple,
+											Anum_pg_index_indclass, &isnull);
+			Assert(!isnull);
+			indclass = (oidvector *) DatumGetPointer(indclassDatum);
+
+			/*
+			 * The given attnum list may match the index columns in any order.
+			 * Check for a match, and extract the appropriate opclasses while
+			 * we're at it.
+			 *
+			 * We know that attnums[] is duplicate-free per the test at the
+			 * start of this function, and we checked above that the number of
+			 * index columns agrees, so if we find a match for each attnums[]
+			 * entry then we must have a one-to-one match in some order.
+			 */
+			for (i = 0; i < numattrs; i++)
+			{
+				found = false;
+				for (j = 0; j < numattrs; j++)
+				{
+					if (attnums[i] == indexStruct->indkey.values[j])
+					{
+						opclasses[i] = indclass->values[j];
+						found = true;
+						break;
+					}
+				}
+				if (!found)
+					break;
+			}
+
+			/*
+			 * Refuse to use a deferrable unique/primary key.  This is per SQL
+			 * spec, and there would be a lot of interesting semantic problems
+			 * if we tried to allow it.
+			 */
+			if (found && !indexStruct->indimmediate)
+			{
+				/*
+				 * Remember that we found an otherwise matching index, so that
+				 * we can generate a more appropriate error message.
+				 */
+				found_deferrable = true;
+				found = false;
+			}
+		}
+		ReleaseSysCache(indexTuple);
+		if (found)
+			break;
+	}
+
+	if (!found)
+	{
+		if (found_deferrable)
+			ereport(ERROR,
+					(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+					 errmsg("cannot use a deferrable unique constraint for referenced table \"%s\"",
+							RelationGetRelationName(pkrel))));
+		else
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_FOREIGN_KEY),
+					 errmsg("there is no unique constraint matching given keys for referenced table \"%s\"",
+							RelationGetRelationName(pkrel))));
+	}
+
+	list_free(indexoidlist);
+
+	return indexoid;
+}
+
+/*
+ * findFkeyCast -
+ *
+ *	Wrapper around find_coercion_pathway() for ATAddForeignKeyConstraint().
+ *	Caller has equal regard for binary coercibility and for an exact match.
+*/
+static CoercionPathType
+findFkeyCast(Oid targetTypeId, Oid sourceTypeId, Oid *funcid)
+{
+	CoercionPathType ret;
+
+	if (targetTypeId == sourceTypeId)
+	{
+		ret = COERCION_PATH_RELABELTYPE;
+		*funcid = InvalidOid;
+	}
+	else
+	{
+		ret = find_coercion_pathway(targetTypeId, sourceTypeId,
+									COERCION_IMPLICIT, funcid);
+		if (ret == COERCION_PATH_NONE)
+			/* A previously-relied-upon cast is now gone. */
+			elog(ERROR, "could not find cast from %u to %u",
+				 sourceTypeId, targetTypeId);
+	}
+
+	return ret;
+}
+
+/*
+ * Permissions checks on the referenced table for ADD FOREIGN KEY
+ *
+ * Note: we have already checked that the user owns the referencing table,
+ * else we'd have failed much earlier; no additional checks are needed for it.
+ */
+static void
+checkFkeyPermissions(Relation rel, int16 *attnums, int natts)
+{
+	Oid			roleid = GetUserId();
+	AclResult	aclresult;
+	int			i;
+
+	/* Okay if we have relation-level REFERENCES permission */
+	aclresult = pg_class_aclcheck(RelationGetRelid(rel), roleid,
+								  ACL_REFERENCES);
+	if (aclresult == ACLCHECK_OK)
+		return;
+	/* Else we must have REFERENCES on each column */
+	for (i = 0; i < natts; i++)
+	{
+		aclresult = pg_attribute_aclcheck(RelationGetRelid(rel), attnums[i],
+										  roleid, ACL_REFERENCES);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, get_relkind_objtype(rel->rd_rel->relkind),
+						   RelationGetRelationName(rel));
+	}
+}
+
+/*
+ * Scan the existing rows in a table to verify they meet a proposed FK
+ * constraint.
+ *
+ * Caller must have opened and locked both relations appropriately.
+ */
+static void
+validateForeignKeyConstraint(char *conname,
+							 Relation rel,
+							 Relation pkrel,
+							 Oid pkindOid,
+							 Oid constraintOid)
+{
+	TupleTableSlot *slot;
+	TableScanDesc scan;
+	Trigger		trig;
+	Snapshot	snapshot;
+	MemoryContext oldcxt;
+	MemoryContext perTupCxt;
+
+	ereport(DEBUG1,
+			(errmsg_internal("validating foreign key constraint \"%s\"", conname)));
+
+	/*
+	 * Build a trigger call structure; we'll need it either way.
+	 */
+	MemSet(&trig, 0, sizeof(trig));
+	trig.tgoid = InvalidOid;
+	trig.tgname = conname;
+	trig.tgenabled = TRIGGER_FIRES_ON_ORIGIN;
+	trig.tgisinternal = true;
+	trig.tgconstrrelid = RelationGetRelid(pkrel);
+	trig.tgconstrindid = pkindOid;
+	trig.tgconstraint = constraintOid;
+	trig.tgdeferrable = false;
+	trig.tginitdeferred = false;
+	/* we needn't fill in remaining fields */
+
+	/*
+	 * See if we can do it with a single LEFT JOIN query.  A false result
+	 * indicates we must proceed with the fire-the-trigger method.
+	 */
+	if (RI_Initial_Check(&trig, rel, pkrel))
+		return;
+
+	/*
+	 * Scan through each tuple, calling RI_FKey_check_ins (insert trigger) as
+	 * if that tuple had just been inserted.  If any of those fail, it should
+	 * ereport(ERROR) and that's that.
+	 */
+	snapshot = RegisterSnapshot(GetLatestSnapshot());
+	slot = table_slot_create(rel, NULL);
+	scan = table_beginscan(rel, snapshot, 0, NULL);
+
+	perTupCxt = AllocSetContextCreate(CurrentMemoryContext,
+									  "validateForeignKeyConstraint",
+									  ALLOCSET_SMALL_SIZES);
+	oldcxt = MemoryContextSwitchTo(perTupCxt);
+
+	while (table_scan_getnextslot(scan, ForwardScanDirection, slot))
+	{
+		LOCAL_FCINFO(fcinfo, 0);
+		TriggerData trigdata = {0};
+
+		CHECK_FOR_INTERRUPTS();
+
+		/*
+		 * Make a call to the trigger function
+		 *
+		 * No parameters are passed, but we do set a context
+		 */
+		MemSet(fcinfo, 0, SizeForFunctionCallInfo(0));
+
+		/*
+		 * We assume RI_FKey_check_ins won't look at flinfo...
+		 */
+		trigdata.type = T_TriggerData;
+		trigdata.tg_event = TRIGGER_EVENT_INSERT | TRIGGER_EVENT_ROW;
+		trigdata.tg_relation = rel;
+		trigdata.tg_trigtuple = ExecFetchSlotHeapTuple(slot, false, NULL);
+		trigdata.tg_trigslot = slot;
+		trigdata.tg_trigger = &trig;
+
+		fcinfo->context = (Node *) &trigdata;
+
+		RI_FKey_check_ins(fcinfo);
+
+		MemoryContextReset(perTupCxt);
+	}
+
+	MemoryContextSwitchTo(oldcxt);
+	MemoryContextDelete(perTupCxt);
+	table_endscan(scan);
+	UnregisterSnapshot(snapshot);
+	ExecDropSingleTupleTableSlot(slot);
+}
+
+/*
+ * CreateFKCheckTrigger
+ *		Creates the insert (on_insert=true) or update "check" trigger that
+ *		implements a given foreign key
+ *
+ * Returns the OID of the so created trigger.
+ */
+static Oid
+CreateFKCheckTrigger(Oid myRelOid, Oid refRelOid, Constraint *fkconstraint,
+					 Oid constraintOid, Oid indexOid, Oid parentTrigOid,
+					 bool on_insert)
+{
+	ObjectAddress trigAddress;
+	CreateTrigStmt *fk_trigger;
+
+	/*
+	 * Note: for a self-referential FK (referencing and referenced tables are
+	 * the same), it is important that the ON UPDATE action fires before the
+	 * CHECK action, since both triggers will fire on the same row during an
+	 * UPDATE event; otherwise the CHECK trigger will be checking a non-final
+	 * state of the row.  Triggers fire in name order, so we ensure this by
+	 * using names like "RI_ConstraintTrigger_a_NNNN" for the action triggers
+	 * and "RI_ConstraintTrigger_c_NNNN" for the check triggers.
+	 */
+	fk_trigger = makeNode(CreateTrigStmt);
+	fk_trigger->replace = false;
+	fk_trigger->isconstraint = true;
+	fk_trigger->trigname = "RI_ConstraintTrigger_c";
+	fk_trigger->relation = NULL;
+
+	/* Either ON INSERT or ON UPDATE */
+	if (on_insert)
+	{
+		fk_trigger->funcname = SystemFuncName("RI_FKey_check_ins");
+		fk_trigger->events = TRIGGER_TYPE_INSERT;
+	}
+	else
+	{
+		fk_trigger->funcname = SystemFuncName("RI_FKey_check_upd");
+		fk_trigger->events = TRIGGER_TYPE_UPDATE;
+	}
+
+	fk_trigger->args = NIL;
+	fk_trigger->row = true;
+	fk_trigger->timing = TRIGGER_TYPE_AFTER;
+	fk_trigger->columns = NIL;
+	fk_trigger->whenClause = NULL;
+	fk_trigger->transitionRels = NIL;
+	fk_trigger->deferrable = fkconstraint->deferrable;
+	fk_trigger->initdeferred = fkconstraint->initdeferred;
+	fk_trigger->constrrel = NULL;
+
+	trigAddress = CreateTrigger(fk_trigger, NULL, myRelOid, refRelOid,
+								constraintOid, indexOid, InvalidOid,
+								parentTrigOid, NULL, true, false);
+
+	/* Make changes-so-far visible */
+	CommandCounterIncrement();
+
+	return trigAddress.objectId;
+}
+
+/*
+ * createForeignKeyActionTriggers
+ *		Create the referenced-side "action" triggers that implement a foreign
+ *		key.
+ *
+ * Returns the OIDs of the so created triggers in *deleteTrigOid and
+ * *updateTrigOid.
+ */
+static void
+createForeignKeyActionTriggers(Relation rel, Oid refRelOid, Constraint *fkconstraint,
+							   Oid constraintOid, Oid indexOid,
+							   Oid parentDelTrigger, Oid parentUpdTrigger,
+							   Oid *deleteTrigOid, Oid *updateTrigOid)
+{
+	CreateTrigStmt *fk_trigger;
+	ObjectAddress trigAddress;
+
+	/*
+	 * Build and execute a CREATE CONSTRAINT TRIGGER statement for the ON
+	 * DELETE action on the referenced table.
+	 */
+	fk_trigger = makeNode(CreateTrigStmt);
+	fk_trigger->replace = false;
+	fk_trigger->isconstraint = true;
+	fk_trigger->trigname = "RI_ConstraintTrigger_a";
+	fk_trigger->relation = NULL;
+	fk_trigger->args = NIL;
+	fk_trigger->row = true;
+	fk_trigger->timing = TRIGGER_TYPE_AFTER;
+	fk_trigger->events = TRIGGER_TYPE_DELETE;
+	fk_trigger->columns = NIL;
+	fk_trigger->whenClause = NULL;
+	fk_trigger->transitionRels = NIL;
+	fk_trigger->constrrel = NULL;
+	switch (fkconstraint->fk_del_action)
+	{
+		case FKCONSTR_ACTION_NOACTION:
+			fk_trigger->deferrable = fkconstraint->deferrable;
+			fk_trigger->initdeferred = fkconstraint->initdeferred;
+			fk_trigger->funcname = SystemFuncName("RI_FKey_noaction_del");
+			break;
+		case FKCONSTR_ACTION_RESTRICT:
+			fk_trigger->deferrable = false;
+			fk_trigger->initdeferred = false;
+			fk_trigger->funcname = SystemFuncName("RI_FKey_restrict_del");
+			break;
+		case FKCONSTR_ACTION_CASCADE:
+			fk_trigger->deferrable = false;
+			fk_trigger->initdeferred = false;
+			fk_trigger->funcname = SystemFuncName("RI_FKey_cascade_del");
+			break;
+		case FKCONSTR_ACTION_SETNULL:
+			fk_trigger->deferrable = false;
+			fk_trigger->initdeferred = false;
+			fk_trigger->funcname = SystemFuncName("RI_FKey_setnull_del");
+			break;
+		case FKCONSTR_ACTION_SETDEFAULT:
+			fk_trigger->deferrable = false;
+			fk_trigger->initdeferred = false;
+			fk_trigger->funcname = SystemFuncName("RI_FKey_setdefault_del");
+			break;
+		default:
+			elog(ERROR, "unrecognized FK action type: %d",
+				 (int) fkconstraint->fk_del_action);
+			break;
+	}
+
+	trigAddress = CreateTrigger(fk_trigger, NULL, refRelOid,
+								RelationGetRelid(rel),
+								constraintOid, indexOid, InvalidOid,
+								parentDelTrigger, NULL, true, false);
+	if (deleteTrigOid)
+		*deleteTrigOid = trigAddress.objectId;
+
+	/* Make changes-so-far visible */
+	CommandCounterIncrement();
+
+	/*
+	 * Build and execute a CREATE CONSTRAINT TRIGGER statement for the ON
+	 * UPDATE action on the referenced table.
+	 */
+	fk_trigger = makeNode(CreateTrigStmt);
+	fk_trigger->replace = false;
+	fk_trigger->isconstraint = true;
+	fk_trigger->trigname = "RI_ConstraintTrigger_a";
+	fk_trigger->relation = NULL;
+	fk_trigger->args = NIL;
+	fk_trigger->row = true;
+	fk_trigger->timing = TRIGGER_TYPE_AFTER;
+	fk_trigger->events = TRIGGER_TYPE_UPDATE;
+	fk_trigger->columns = NIL;
+	fk_trigger->whenClause = NULL;
+	fk_trigger->transitionRels = NIL;
+	fk_trigger->constrrel = NULL;
+	switch (fkconstraint->fk_upd_action)
+	{
+		case FKCONSTR_ACTION_NOACTION:
+			fk_trigger->deferrable = fkconstraint->deferrable;
+			fk_trigger->initdeferred = fkconstraint->initdeferred;
+			fk_trigger->funcname = SystemFuncName("RI_FKey_noaction_upd");
+			break;
+		case FKCONSTR_ACTION_RESTRICT:
+			fk_trigger->deferrable = false;
+			fk_trigger->initdeferred = false;
+			fk_trigger->funcname = SystemFuncName("RI_FKey_restrict_upd");
+			break;
+		case FKCONSTR_ACTION_CASCADE:
+			fk_trigger->deferrable = false;
+			fk_trigger->initdeferred = false;
+			fk_trigger->funcname = SystemFuncName("RI_FKey_cascade_upd");
+			break;
+		case FKCONSTR_ACTION_SETNULL:
+			fk_trigger->deferrable = false;
+			fk_trigger->initdeferred = false;
+			fk_trigger->funcname = SystemFuncName("RI_FKey_setnull_upd");
+			break;
+		case FKCONSTR_ACTION_SETDEFAULT:
+			fk_trigger->deferrable = false;
+			fk_trigger->initdeferred = false;
+			fk_trigger->funcname = SystemFuncName("RI_FKey_setdefault_upd");
+			break;
+		default:
+			elog(ERROR, "unrecognized FK action type: %d",
+				 (int) fkconstraint->fk_upd_action);
+			break;
+	}
+
+	trigAddress = CreateTrigger(fk_trigger, NULL, refRelOid,
+								RelationGetRelid(rel),
+								constraintOid, indexOid, InvalidOid,
+								parentUpdTrigger, NULL, true, false);
+	if (updateTrigOid)
+		*updateTrigOid = trigAddress.objectId;
+}
+
+/*
+ * createForeignKeyCheckTriggers
+ *		Create the referencing-side "check" triggers that implement a foreign
+ *		key.
+ *
+ * Returns the OIDs of the so created triggers in *insertTrigOid and
+ * *updateTrigOid.
+ */
+static void
+createForeignKeyCheckTriggers(Oid myRelOid, Oid refRelOid,
+							  Constraint *fkconstraint, Oid constraintOid,
+							  Oid indexOid,
+							  Oid parentInsTrigger, Oid parentUpdTrigger,
+							  Oid *insertTrigOid, Oid *updateTrigOid)
+{
+	*insertTrigOid = CreateFKCheckTrigger(myRelOid, refRelOid, fkconstraint,
+										  constraintOid, indexOid,
+										  parentInsTrigger, true);
+	*updateTrigOid = CreateFKCheckTrigger(myRelOid, refRelOid, fkconstraint,
+										  constraintOid, indexOid,
+										  parentUpdTrigger, false);
+}
+
+/*
+ * ALTER TABLE DROP CONSTRAINT
+ *
+ * Like DROP COLUMN, we can't use the normal ALTER TABLE recursion mechanism.
+ */
+static void
+ATExecDropConstraint(Relation rel, const char *constrName,
+					 DropBehavior behavior,
+					 bool recurse, bool recursing,
+					 bool missing_ok, LOCKMODE lockmode)
+{
+	List	   *children;
+	ListCell   *child;
+	Relation	conrel;
+	Form_pg_constraint con;
+	SysScanDesc scan;
+	ScanKeyData skey[3];
+	HeapTuple	tuple;
+	bool		found = false;
+	bool		is_no_inherit_constraint = false;
+	char		contype;
+
+	/* At top level, permission check was done in ATPrepCmd, else do it */
+	if (recursing)
+		ATSimplePermissions(AT_DropConstraint, rel, ATT_TABLE | ATT_FOREIGN_TABLE);
+
+	conrel = table_open(ConstraintRelationId, RowExclusiveLock);
+
+	/*
+	 * Find and drop the target constraint
+	 */
+	ScanKeyInit(&skey[0],
+				Anum_pg_constraint_conrelid,
+				BTEqualStrategyNumber, F_OIDEQ,
+				ObjectIdGetDatum(RelationGetRelid(rel)));
+	ScanKeyInit(&skey[1],
+				Anum_pg_constraint_contypid,
+				BTEqualStrategyNumber, F_OIDEQ,
+				ObjectIdGetDatum(InvalidOid));
+	ScanKeyInit(&skey[2],
+				Anum_pg_constraint_conname,
+				BTEqualStrategyNumber, F_NAMEEQ,
+				CStringGetDatum(constrName));
+	scan = systable_beginscan(conrel, ConstraintRelidTypidNameIndexId,
+							  true, NULL, 3, skey);
+
+	/* There can be at most one matching row */
+	if (HeapTupleIsValid(tuple = systable_getnext(scan)))
+	{
+		ObjectAddress conobj;
+
+		con = (Form_pg_constraint) GETSTRUCT(tuple);
+
+		/* Don't drop inherited constraints */
+		if (con->coninhcount > 0 && !recursing)
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
+					 errmsg("cannot drop inherited constraint \"%s\" of relation \"%s\"",
+							constrName, RelationGetRelationName(rel))));
+
+		is_no_inherit_constraint = con->connoinherit;
+		contype = con->contype;
+
+		/*
+		 * If it's a foreign-key constraint, we'd better lock the referenced
+		 * table and check that that's not in use, just as we've already done
+		 * for the constrained table (else we might, eg, be dropping a trigger
+		 * that has unfired events).  But we can/must skip that in the
+		 * self-referential case.
+		 */
+		if (contype == CONSTRAINT_FOREIGN &&
+			con->confrelid != RelationGetRelid(rel))
+		{
+			Relation	frel;
+
+			/* Must match lock taken by RemoveTriggerById: */
+			frel = table_open(con->confrelid, AccessExclusiveLock);
+			CheckTableNotInUse(frel, "ALTER TABLE");
+			table_close(frel, NoLock);
+		}
+
+		/*
+		 * Perform the actual constraint deletion
+		 */
+		conobj.classId = ConstraintRelationId;
+		conobj.objectId = con->oid;
+		conobj.objectSubId = 0;
+
+		performDeletion(&conobj, behavior, 0);
+
+		found = true;
+	}
+
+	systable_endscan(scan);
+
+	if (!found)
+	{
+		if (!missing_ok)
+		{
+			ereport(ERROR,
+					(errcode(ERRCODE_UNDEFINED_OBJECT),
+					 errmsg("constraint \"%s\" of relation \"%s\" does not exist",
+							constrName, RelationGetRelationName(rel))));
+		}
+		else
+		{
+			ereport(NOTICE,
+					(errmsg("constraint \"%s\" of relation \"%s\" does not exist, skipping",
+							constrName, RelationGetRelationName(rel))));
+			table_close(conrel, RowExclusiveLock);
+			return;
+		}
+	}
+
+	/*
+	 * For partitioned tables, non-CHECK inherited constraints are dropped via
+	 * the dependency mechanism, so we're done here.
+	 */
+	if (contype != CONSTRAINT_CHECK &&
+		rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
+	{
+		table_close(conrel, RowExclusiveLock);
+		return;
+	}
+
+	/*
+	 * Propagate to children as appropriate.  Unlike most other ALTER
+	 * routines, we have to do this one level of recursion at a time; we can't
+	 * use find_all_inheritors to do it in one pass.
+	 */
+	if (!is_no_inherit_constraint)
+		children = find_inheritance_children(RelationGetRelid(rel), lockmode);
+	else
+		children = NIL;
+
+	/*
+	 * For a partitioned table, if partitions exist and we are told not to
+	 * recurse, it's a user error.  It doesn't make sense to have a constraint
+	 * be defined only on the parent, especially if it's a partitioned table.
+	 */
+	if (rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE &&
+		children != NIL && !recurse)
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
+				 errmsg("cannot remove constraint from only the partitioned table when partitions exist"),
+				 errhint("Do not specify the ONLY keyword.")));
+
+	foreach(child, children)
+	{
+		Oid			childrelid = lfirst_oid(child);
+		Relation	childrel;
+		HeapTuple	copy_tuple;
+
+		/* find_inheritance_children already got lock */
+		childrel = table_open(childrelid, NoLock);
+		CheckTableNotInUse(childrel, "ALTER TABLE");
+
+		ScanKeyInit(&skey[0],
+					Anum_pg_constraint_conrelid,
+					BTEqualStrategyNumber, F_OIDEQ,
+					ObjectIdGetDatum(childrelid));
+		ScanKeyInit(&skey[1],
+					Anum_pg_constraint_contypid,
+					BTEqualStrategyNumber, F_OIDEQ,
+					ObjectIdGetDatum(InvalidOid));
+		ScanKeyInit(&skey[2],
+					Anum_pg_constraint_conname,
+					BTEqualStrategyNumber, F_NAMEEQ,
+					CStringGetDatum(constrName));
+		scan = systable_beginscan(conrel, ConstraintRelidTypidNameIndexId,
+								  true, NULL, 3, skey);
+
+		/* There can be at most one matching row */
+		if (!HeapTupleIsValid(tuple = systable_getnext(scan)))
+			ereport(ERROR,
+					(errcode(ERRCODE_UNDEFINED_OBJECT),
+					 errmsg("constraint \"%s\" of relation \"%s\" does not exist",
+							constrName,
+							RelationGetRelationName(childrel))));
+
+		copy_tuple = heap_copytuple(tuple);
+
+		systable_endscan(scan);
+
+		con = (Form_pg_constraint) GETSTRUCT(copy_tuple);
+
+		/* Right now only CHECK constraints can be inherited */
+		if (con->contype != CONSTRAINT_CHECK)
+			elog(ERROR, "inherited constraint is not a CHECK constraint");
+
+		if (con->coninhcount <= 0)	/* shouldn't happen */
+			elog(ERROR, "relation %u has non-inherited constraint \"%s\"",
+				 childrelid, constrName);
+
+		if (recurse)
+		{
+			/*
+			 * If the child constraint has other definition sources, just
+			 * decrement its inheritance count; if not, recurse to delete it.
+			 */
+			if (con->coninhcount == 1 && !con->conislocal)
+			{
+				/* Time to delete this child constraint, too */
+				ATExecDropConstraint(childrel, constrName, behavior,
+									 true, true,
+									 false, lockmode);
+			}
+			else
+			{
+				/* Child constraint must survive my deletion */
+				con->coninhcount--;
+				CatalogTupleUpdate(conrel, &copy_tuple->t_self, copy_tuple);
+
+				/* Make update visible */
+				CommandCounterIncrement();
+			}
+		}
+		else
+		{
+			/*
+			 * If we were told to drop ONLY in this table (no recursion), we
+			 * need to mark the inheritors' constraints as locally defined
+			 * rather than inherited.
+			 */
+			con->coninhcount--;
+			con->conislocal = true;
+
+			CatalogTupleUpdate(conrel, &copy_tuple->t_self, copy_tuple);
+
+			/* Make update visible */
+			CommandCounterIncrement();
+		}
+
+		heap_freetuple(copy_tuple);
+
+		table_close(childrel, NoLock);
+	}
+
+	table_close(conrel, RowExclusiveLock);
+}
+
+/*
+ * ALTER COLUMN TYPE
+ *
+ * Unlike other subcommand types, we do parse transformation for ALTER COLUMN
+ * TYPE during phase 1 --- the AlterTableCmd passed in here is already
+ * transformed (and must be, because we rely on some transformed fields).
+ *
+ * The point of this is that the execution of all ALTER COLUMN TYPEs for a
+ * table will be done "in parallel" during phase 3, so all the USING
+ * expressions should be parsed assuming the original column types.  Also,
+ * this allows a USING expression to refer to a field that will be dropped.
+ *
+ * To make this work safely, AT_PASS_DROP then AT_PASS_ALTER_TYPE must be
+ * the first two execution steps in phase 2; they must not see the effects
+ * of any other subcommand types, since the USING expressions are parsed
+ * against the unmodified table's state.
+ */
+static void
+ATPrepAlterColumnType(List **wqueue,
+					  AlteredTableInfo *tab, Relation rel,
+					  bool recurse, bool recursing,
+					  AlterTableCmd *cmd, LOCKMODE lockmode,
+					  AlterTableUtilityContext *context)
+{
+	char	   *colName = cmd->name;
+	ColumnDef  *def = (ColumnDef *) cmd->def;
+	TypeName   *typeName = def->typeName;
+	Node	   *transform = def->cooked_default;
+	HeapTuple	tuple;
+	Form_pg_attribute attTup;
+	AttrNumber	attnum;
+	Oid			targettype;
+	int32		targettypmod;
+	Oid			targetcollid;
+	NewColumnValue *newval;
+	ParseState *pstate = make_parsestate(NULL);
+	AclResult	aclresult;
+	bool		is_expr;
+
+	if (rel->rd_rel->reloftype && !recursing)
+		ereport(ERROR,
+				(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+				 errmsg("cannot alter column type of typed table")));
+
+	/* lookup the attribute so we can check inheritance status */
+	tuple = SearchSysCacheAttName(RelationGetRelid(rel), colName);
+	if (!HeapTupleIsValid(tuple))
+		ereport(ERROR,
+				(errcode(ERRCODE_UNDEFINED_COLUMN),
+				 errmsg("column \"%s\" of relation \"%s\" does not exist",
+						colName, RelationGetRelationName(rel))));
+	attTup = (Form_pg_attribute) GETSTRUCT(tuple);
+	attnum = attTup->attnum;
+
+	/* Can't alter a system attribute */
+	if (attnum <= 0)
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("cannot alter system column \"%s\"",
+						colName)));
+
+	/*
+	 * Don't alter inherited columns.  At outer level, there had better not be
+	 * any inherited definition; when recursing, we assume this was checked at
+	 * the parent level (see below).
+	 */
+	if (attTup->attinhcount > 0 && !recursing)
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
+				 errmsg("cannot alter inherited column \"%s\"",
+						colName)));
+
+	/* Don't alter columns used in the partition key */
+	if (has_partition_attrs(rel,
+							bms_make_singleton(attnum - FirstLowInvalidHeapAttributeNumber),
+							&is_expr))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
+				 errmsg("cannot alter column \"%s\" because it is part of the partition key of relation \"%s\"",
+						colName, RelationGetRelationName(rel))));
+
+	/* Look up the target type */
+	typenameTypeIdAndMod(NULL, typeName, &targettype, &targettypmod);
+
+	aclresult = pg_type_aclcheck(targettype, GetUserId(), ACL_USAGE);
+	if (aclresult != ACLCHECK_OK)
+		aclcheck_error_type(aclresult, targettype);
+
+	/* And the collation */
+	targetcollid = GetColumnDefCollation(NULL, def, targettype);
+
+	/* make sure datatype is legal for a column */
+	CheckAttributeType(colName, targettype, targetcollid,
+					   list_make1_oid(rel->rd_rel->reltype),
+					   0);
+
+	if (tab->relkind == RELKIND_RELATION ||
+		tab->relkind == RELKIND_PARTITIONED_TABLE)
+	{
+		/*
+		 * Set up an expression to transform the old data value to the new
+		 * type. If a USING option was given, use the expression as
+		 * transformed by transformAlterTableStmt, else just take the old
+		 * value and try to coerce it.  We do this first so that type
+		 * incompatibility can be detected before we waste effort, and because
+		 * we need the expression to be parsed against the original table row
+		 * type.
+		 */
+		if (!transform)
+		{
+			transform = (Node *) makeVar(1, attnum,
+										 attTup->atttypid, attTup->atttypmod,
+										 attTup->attcollation,
+										 0);
+		}
+
+		transform = coerce_to_target_type(pstate,
+										  transform, exprType(transform),
+										  targettype, targettypmod,
+										  COERCION_ASSIGNMENT,
+										  COERCE_IMPLICIT_CAST,
+										  -1);
+		if (transform == NULL)
+		{
+			/* error text depends on whether USING was specified or not */
+			if (def->cooked_default != NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("result of USING clause for column \"%s\""
+								" cannot be cast automatically to type %s",
+								colName, format_type_be(targettype)),
+						 errhint("You might need to add an explicit cast.")));
+			else
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("column \"%s\" cannot be cast automatically to type %s",
+								colName, format_type_be(targettype)),
+				/* translator: USING is SQL, don't translate it */
+						 errhint("You might need to specify \"USING %s::%s\".",
+								 quote_identifier(colName),
+								 format_type_with_typemod(targettype,
+														  targettypmod))));
+		}
+
+		/* Fix collations after all else */
+		assign_expr_collations(pstate, transform);
+
+		/* Plan the expr now so we can accurately assess the need to rewrite. */
+		transform = (Node *) expression_planner((Expr *) transform);
+
+		/*
+		 * Add a work queue item to make ATRewriteTable update the column
+		 * contents.
+		 */
+		newval = (NewColumnValue *) palloc0(sizeof(NewColumnValue));
+		newval->attnum = attnum;
+		newval->expr = (Expr *) transform;
+		newval->is_generated = false;
+
+		tab->newvals = lappend(tab->newvals, newval);
+		if (ATColumnChangeRequiresRewrite(transform, attnum))
+			tab->rewrite |= AT_REWRITE_COLUMN_REWRITE;
+	}
+	else if (transform)
+		ereport(ERROR,
+				(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+				 errmsg("\"%s\" is not a table",
+						RelationGetRelationName(rel))));
+
+	if (!RELKIND_HAS_STORAGE(tab->relkind))
+	{
+		/*
+		 * For relations without storage, do this check now.  Regular tables
+		 * will check it later when the table is being rewritten.
+		 */
+		find_composite_type_dependencies(rel->rd_rel->reltype, rel, NULL);
+	}
+
+	ReleaseSysCache(tuple);
+
+	/*
+	 * Recurse manually by queueing a new command for each child, if
+	 * necessary. We cannot apply ATSimpleRecursion here because we need to
+	 * remap attribute numbers in the USING expression, if any.
+	 *
+	 * If we are told not to recurse, there had better not be any child
+	 * tables; else the alter would put them out of step.
+	 */
+	if (recurse)
+	{
+		Oid			relid = RelationGetRelid(rel);
+		List	   *child_oids,
+				   *child_numparents;
+		ListCell   *lo,
+				   *li;
+
+		child_oids = find_all_inheritors(relid, lockmode,
+										 &child_numparents);
+
+		/*
+		 * find_all_inheritors does the recursive search of the inheritance
+		 * hierarchy, so all we have to do is process all of the relids in the
+		 * list that it returns.
+		 */
+		forboth(lo, child_oids, li, child_numparents)
+		{
+			Oid			childrelid = lfirst_oid(lo);
+			int			numparents = lfirst_int(li);
+			Relation	childrel;
+			HeapTuple	childtuple;
+			Form_pg_attribute childattTup;
+
+			if (childrelid == relid)
+				continue;
+
+			/* find_all_inheritors already got lock */
+			childrel = relation_open(childrelid, NoLock);
+			CheckTableNotInUse(childrel, "ALTER TABLE");
+
+			/*
+			 * Verify that the child doesn't have any inherited definitions of
+			 * this column that came from outside this inheritance hierarchy.
+			 * (renameatt makes a similar test, though in a different way
+			 * because of its different recursion mechanism.)
+			 */
+			childtuple = SearchSysCacheAttName(RelationGetRelid(childrel),
+											   colName);
+			if (!HeapTupleIsValid(childtuple))
+				ereport(ERROR,
+						(errcode(ERRCODE_UNDEFINED_COLUMN),
+						 errmsg("column \"%s\" of relation \"%s\" does not exist",
+								colName, RelationGetRelationName(childrel))));
+			childattTup = (Form_pg_attribute) GETSTRUCT(childtuple);
+
+			if (childattTup->attinhcount > numparents)
+				ereport(ERROR,
+						(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
+						 errmsg("cannot alter inherited column \"%s\" of relation \"%s\"",
+								colName, RelationGetRelationName(childrel))));
+
+			ReleaseSysCache(childtuple);
+
+			/*
+			 * Remap the attribute numbers.  If no USING expression was
+			 * specified, there is no need for this step.
+			 */
+			if (def->cooked_default)
+			{
+				AttrMap    *attmap;
+				bool		found_whole_row;
+
+				/* create a copy to scribble on */
+				cmd = copyObject(cmd);
+
+				attmap = build_attrmap_by_name(RelationGetDescr(childrel),
+											   RelationGetDescr(rel));
+				((ColumnDef *) cmd->def)->cooked_default =
+					map_variable_attnos(def->cooked_default,
+										1, 0,
+										attmap,
+										InvalidOid, &found_whole_row);
+				if (found_whole_row)
+					ereport(ERROR,
+							(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+							 errmsg("cannot convert whole-row table reference"),
+							 errdetail("USING expression contains a whole-row table reference.")));
+				pfree(attmap);
+			}
+			ATPrepCmd(wqueue, childrel, cmd, false, true, lockmode, context);
+			relation_close(childrel, NoLock);
+		}
+	}
+	else if (!recursing &&
+			 find_inheritance_children(RelationGetRelid(rel), NoLock) != NIL)
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
+				 errmsg("type of inherited column \"%s\" must be changed in child tables too",
+						colName)));
+
+	if (tab->relkind == RELKIND_COMPOSITE_TYPE)
+		ATTypedTableRecursion(wqueue, rel, cmd, lockmode, context);
+}
+
+/*
+ * When the data type of a column is changed, a rewrite might not be required
+ * if the new type is sufficiently identical to the old one, and the USING
+ * clause isn't trying to insert some other value.  It's safe to skip the
+ * rewrite in these cases:
+ *
+ * - the old type is binary coercible to the new type
+ * - the new type is an unconstrained domain over the old type
+ * - {NEW,OLD} or {OLD,NEW} is {timestamptz,timestamp} and the timezone is UTC
+ *
+ * In the case of a constrained domain, we could get by with scanning the
+ * table and checking the constraint rather than actually rewriting it, but we
+ * don't currently try to do that.
+ */
+static bool
+ATColumnChangeRequiresRewrite(Node *expr, AttrNumber varattno)
+{
+	Assert(expr != NULL);
+
+	for (;;)
+	{
+		/* only one varno, so no need to check that */
+		if (IsA(expr, Var) && ((Var *) expr)->varattno == varattno)
+			return false;
+		else if (IsA(expr, RelabelType))
+			expr = (Node *) ((RelabelType *) expr)->arg;
+		else if (IsA(expr, CoerceToDomain))
+		{
+			CoerceToDomain *d = (CoerceToDomain *) expr;
+
+			if (DomainHasConstraints(d->resulttype))
+				return true;
+			expr = (Node *) d->arg;
+		}
+		else if (IsA(expr, FuncExpr))
+		{
+			FuncExpr   *f = (FuncExpr *) expr;
+
+			switch (f->funcid)
+			{
+				case F_TIMESTAMPTZ_TIMESTAMP:
+				case F_TIMESTAMP_TIMESTAMPTZ:
+					if (TimestampTimestampTzRequiresRewrite())
+						return true;
+					else
+						expr = linitial(f->args);
+					break;
+				default:
+					return true;
+			}
+		}
+		else
+			return true;
+	}
+}
+
+/*
+ * ALTER COLUMN .. SET DATA TYPE
+ *
+ * Return the address of the modified column.
+ */
+static ObjectAddress
+ATExecAlterColumnType(AlteredTableInfo *tab, Relation rel,
+					  AlterTableCmd *cmd, LOCKMODE lockmode)
+{
+	char	   *colName = cmd->name;
+	ColumnDef  *def = (ColumnDef *) cmd->def;
+	TypeName   *typeName = def->typeName;
+	HeapTuple	heapTup;
+	Form_pg_attribute attTup,
+				attOldTup;
+	AttrNumber	attnum;
+	HeapTuple	typeTuple;
+	Form_pg_type tform;
+	Oid			targettype;
+	int32		targettypmod;
+	Oid			targetcollid;
+	Node	   *defaultexpr;
+	Relation	attrelation;
+	Relation	depRel;
+	ScanKeyData key[3];
+	SysScanDesc scan;
+	HeapTuple	depTup;
+	ObjectAddress address;
+
+	/*
+	 * Clear all the missing values if we're rewriting the table, since this
+	 * renders them pointless.
+	 */
+	if (tab->rewrite)
+	{
+		Relation	newrel;
+
+		newrel = table_open(RelationGetRelid(rel), NoLock);
+		RelationClearMissing(newrel);
+		relation_close(newrel, NoLock);
+		/* make sure we don't conflict with later attribute modifications */
+		CommandCounterIncrement();
+	}
+
+	attrelation = table_open(AttributeRelationId, RowExclusiveLock);
+
+	/* Look up the target column */
+	heapTup = SearchSysCacheCopyAttName(RelationGetRelid(rel), colName);
+	if (!HeapTupleIsValid(heapTup)) /* shouldn't happen */
+		ereport(ERROR,
+				(errcode(ERRCODE_UNDEFINED_COLUMN),
+				 errmsg("column \"%s\" of relation \"%s\" does not exist",
+						colName, RelationGetRelationName(rel))));
+	attTup = (Form_pg_attribute) GETSTRUCT(heapTup);
+	attnum = attTup->attnum;
+	attOldTup = TupleDescAttr(tab->oldDesc, attnum - 1);
+
+	/* Check for multiple ALTER TYPE on same column --- can't cope */
+	if (attTup->atttypid != attOldTup->atttypid ||
+		attTup->atttypmod != attOldTup->atttypmod)
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("cannot alter type of column \"%s\" twice",
+						colName)));
+
+	/* Look up the target type (should not fail, since prep found it) */
+	typeTuple = typenameType(NULL, typeName, &targettypmod);
+	tform = (Form_pg_type) GETSTRUCT(typeTuple);
+	targettype = tform->oid;
+	/* And the collation */
+	targetcollid = GetColumnDefCollation(NULL, def, targettype);
+
+	/*
+	 * If there is a default expression for the column, get it and ensure we
+	 * can coerce it to the new datatype.  (We must do this before changing
+	 * the column type, because build_column_default itself will try to
+	 * coerce, and will not issue the error message we want if it fails.)
+	 *
+	 * We remove any implicit coercion steps at the top level of the old
+	 * default expression; this has been agreed to satisfy the principle of
+	 * least surprise.  (The conversion to the new column type should act like
+	 * it started from what the user sees as the stored expression, and the
+	 * implicit coercions aren't going to be shown.)
+	 */
+	if (attTup->atthasdef)
+	{
+		defaultexpr = build_column_default(rel, attnum);
+		Assert(defaultexpr);
+		defaultexpr = strip_implicit_coercions(defaultexpr);
+		defaultexpr = coerce_to_target_type(NULL,	/* no UNKNOWN params */
+											defaultexpr, exprType(defaultexpr),
+											targettype, targettypmod,
+											COERCION_ASSIGNMENT,
+											COERCE_IMPLICIT_CAST,
+											-1);
+		if (defaultexpr == NULL)
+		{
+			if (attTup->attgenerated)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("generation expression for column \"%s\" cannot be cast automatically to type %s",
+								colName, format_type_be(targettype))));
+			else
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("default for column \"%s\" cannot be cast automatically to type %s",
+								colName, format_type_be(targettype))));
+		}
+	}
+	else
+		defaultexpr = NULL;
+
+	/*
+	 * Find everything that depends on the column (constraints, indexes, etc),
+	 * and record enough information to let us recreate the objects.
+	 *
+	 * The actual recreation does not happen here, but only after we have
+	 * performed all the individual ALTER TYPE operations.  We have to save
+	 * the info before executing ALTER TYPE, though, else the deparser will
+	 * get confused.
+	 */
+	depRel = table_open(DependRelationId, RowExclusiveLock);
+
+	ScanKeyInit(&key[0],
+				Anum_pg_depend_refclassid,
+				BTEqualStrategyNumber, F_OIDEQ,
+				ObjectIdGetDatum(RelationRelationId));
+	ScanKeyInit(&key[1],
+				Anum_pg_depend_refobjid,
+				BTEqualStrategyNumber, F_OIDEQ,
+				ObjectIdGetDatum(RelationGetRelid(rel)));
+	ScanKeyInit(&key[2],
+				Anum_pg_depend_refobjsubid,
+				BTEqualStrategyNumber, F_INT4EQ,
+				Int32GetDatum((int32) attnum));
+
+	scan = systable_beginscan(depRel, DependReferenceIndexId, true,
+							  NULL, 3, key);
+
+	while (HeapTupleIsValid(depTup = systable_getnext(scan)))
+	{
+		Form_pg_depend foundDep = (Form_pg_depend) GETSTRUCT(depTup);
+		ObjectAddress foundObject;
+
+		foundObject.classId = foundDep->classid;
+		foundObject.objectId = foundDep->objid;
+		foundObject.objectSubId = foundDep->objsubid;
+
+		switch (getObjectClass(&foundObject))
+		{
+			case OCLASS_CLASS:
+				{
+					char		relKind = get_rel_relkind(foundObject.objectId);
+
+					if (relKind == RELKIND_INDEX ||
+						relKind == RELKIND_PARTITIONED_INDEX)
+					{
+						Assert(foundObject.objectSubId == 0);
+						RememberIndexForRebuilding(foundObject.objectId, tab);
+					}
+					else if (relKind == RELKIND_SEQUENCE)
+					{
+						/*
+						 * This must be a SERIAL column's sequence.  We need
+						 * not do anything to it.
+						 */
+						Assert(foundObject.objectSubId == 0);
+					}
+					else
+					{
+						/* Not expecting any other direct dependencies... */
+						elog(ERROR, "unexpected object depending on column: %s",
+							 getObjectDescription(&foundObject, false));
+					}
+					break;
+				}
+
+			case OCLASS_CONSTRAINT:
+				Assert(foundObject.objectSubId == 0);
+				RememberConstraintForRebuilding(foundObject.objectId, tab);
+				break;
+
+			case OCLASS_REWRITE:
+				/* XXX someday see if we can cope with revising views */
+				ereport(ERROR,
+						(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+						 errmsg("cannot alter type of a column used by a view or rule"),
+						 errdetail("%s depends on column \"%s\"",
+								   getObjectDescription(&foundObject, false),
+								   colName)));
+				break;
+
+			case OCLASS_TRIGGER:
+
+				/*
+				 * A trigger can depend on a column because the column is
+				 * specified as an update target, or because the column is
+				 * used in the trigger's WHEN condition.  The first case would
+				 * not require any extra work, but the second case would
+				 * require updating the WHEN expression, which will take a
+				 * significant amount of new code.  Since we can't easily tell
+				 * which case applies, we punt for both.  FIXME someday.
+				 */
+				ereport(ERROR,
+						(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+						 errmsg("cannot alter type of a column used in a trigger definition"),
+						 errdetail("%s depends on column \"%s\"",
+								   getObjectDescription(&foundObject, false),
+								   colName)));
+				break;
+
+			case OCLASS_POLICY:
+
+				/*
+				 * A policy can depend on a column because the column is
+				 * specified in the policy's USING or WITH CHECK qual
+				 * expressions.  It might be possible to rewrite and recheck
+				 * the policy expression, but punt for now.  It's certainly
+				 * easy enough to remove and recreate the policy; still, FIXME
+				 * someday.
+				 */
+				ereport(ERROR,
+						(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+						 errmsg("cannot alter type of a column used in a policy definition"),
+						 errdetail("%s depends on column \"%s\"",
+								   getObjectDescription(&foundObject, false),
+								   colName)));
+				break;
+
+			case OCLASS_DEFAULT:
+				{
+					ObjectAddress col = GetAttrDefaultColumnAddress(foundObject.objectId);
+
+					if (col.objectId == RelationGetRelid(rel) &&
+						col.objectSubId == attnum)
+					{
+						/*
+						 * Ignore the column's own default expression, which
+						 * we will deal with below.
+						 */
+						Assert(defaultexpr);
+					}
+					else
+					{
+						/*
+						 * This must be a reference from the expression of a
+						 * generated column elsewhere in the same table.
+						 * Changing the type of a column that is used by a
+						 * generated column is not allowed by SQL standard, so
+						 * just punt for now.  It might be doable with some
+						 * thinking and effort.
+						 */
+						ereport(ERROR,
+								(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+								 errmsg("cannot alter type of a column used by a generated column"),
+								 errdetail("Column \"%s\" is used by generated column \"%s\".",
+										   colName,
+										   get_attname(col.objectId,
+													   col.objectSubId,
+													   false))));
+					}
+					break;
+				}
+
+			case OCLASS_STATISTIC_EXT:
+
+				/*
+				 * Give the extended-stats machinery a chance to fix anything
+				 * that this column type change would break.
+				 */
+				RememberStatisticsForRebuilding(foundObject.objectId, tab);
+				break;
+
+			case OCLASS_PROC:
+			case OCLASS_TYPE:
+			case OCLASS_CAST:
+			case OCLASS_COLLATION:
+			case OCLASS_CONVERSION:
+			case OCLASS_LANGUAGE:
+			case OCLASS_LARGEOBJECT:
+			case OCLASS_OPERATOR:
+			case OCLASS_OPCLASS:
+			case OCLASS_OPFAMILY:
+			case OCLASS_AM:
+			case OCLASS_AMOP:
+			case OCLASS_AMPROC:
+			case OCLASS_SCHEMA:
+			case OCLASS_TSPARSER:
+			case OCLASS_TSDICT:
+			case OCLASS_TSTEMPLATE:
+			case OCLASS_TSCONFIG:
+			case OCLASS_ROLE:
+			case OCLASS_DATABASE:
+			case OCLASS_TBLSPACE:
+			case OCLASS_FDW:
+			case OCLASS_FOREIGN_SERVER:
+			case OCLASS_USER_MAPPING:
+			case OCLASS_DEFACL:
+			case OCLASS_EXTENSION:
+			case OCLASS_EVENT_TRIGGER:
+			case OCLASS_PARAMETER_ACL:
+			case OCLASS_PUBLICATION:
+			case OCLASS_PUBLICATION_NAMESPACE:
+			case OCLASS_PUBLICATION_REL:
+			case OCLASS_SUBSCRIPTION:
+			case OCLASS_TRANSFORM:
+
+				/*
+				 * We don't expect any of these sorts of objects to depend on
+				 * a column.
+				 */
+				elog(ERROR, "unexpected object depending on column: %s",
+					 getObjectDescription(&foundObject, false));
+				break;
+
+				/*
+				 * There's intentionally no default: case here; we want the
+				 * compiler to warn if a new OCLASS hasn't been handled above.
+				 */
+		}
+	}
+
+	systable_endscan(scan);
+
+	/*
+	 * Now scan for dependencies of this column on other things.  The only
+	 * things we should find are the dependency on the column datatype and
+	 * possibly a collation dependency.  Those can be removed.
+	 */
+	ScanKeyInit(&key[0],
+				Anum_pg_depend_classid,
+				BTEqualStrategyNumber, F_OIDEQ,
+				ObjectIdGetDatum(RelationRelationId));
+	ScanKeyInit(&key[1],
+				Anum_pg_depend_objid,
+				BTEqualStrategyNumber, F_OIDEQ,
+				ObjectIdGetDatum(RelationGetRelid(rel)));
+	ScanKeyInit(&key[2],
+				Anum_pg_depend_objsubid,
+				BTEqualStrategyNumber, F_INT4EQ,
+				Int32GetDatum((int32) attnum));
+
+	scan = systable_beginscan(depRel, DependDependerIndexId, true,
+							  NULL, 3, key);
+
+	while (HeapTupleIsValid(depTup = systable_getnext(scan)))
+	{
+		Form_pg_depend foundDep = (Form_pg_depend) GETSTRUCT(depTup);
+		ObjectAddress foundObject;
+
+		foundObject.classId = foundDep->refclassid;
+		foundObject.objectId = foundDep->refobjid;
+		foundObject.objectSubId = foundDep->refobjsubid;
+
+		if (foundDep->deptype != DEPENDENCY_NORMAL)
+			elog(ERROR, "found unexpected dependency type '%c'",
+				 foundDep->deptype);
+		if (!(foundDep->refclassid == TypeRelationId &&
+			  foundDep->refobjid == attTup->atttypid) &&
+			!(foundDep->refclassid == CollationRelationId &&
+			  foundDep->refobjid == attTup->attcollation))
+			elog(ERROR, "found unexpected dependency for column: %s",
+				 getObjectDescription(&foundObject, false));
+
+		CatalogTupleDelete(depRel, &depTup->t_self);
+	}
+
+	systable_endscan(scan);
+
+	table_close(depRel, RowExclusiveLock);
+
+	/*
+	 * Here we go --- change the recorded column type and collation.  (Note
+	 * heapTup is a copy of the syscache entry, so okay to scribble on.) First
+	 * fix up the missing value if any.
+	 */
+	if (attTup->atthasmissing)
+	{
+		Datum		missingval;
+		bool		missingNull;
+
+		/* if rewrite is true the missing value should already be cleared */
+		Assert(tab->rewrite == 0);
+
+		/* Get the missing value datum */
+		missingval = heap_getattr(heapTup,
+								  Anum_pg_attribute_attmissingval,
+								  attrelation->rd_att,
+								  &missingNull);
+
+		/* if it's a null array there is nothing to do */
+
+		if (!missingNull)
+		{
+			/*
+			 * Get the datum out of the array and repack it in a new array
+			 * built with the new type data. We assume that since the table
+			 * doesn't need rewriting, the actual Datum doesn't need to be
+			 * changed, only the array metadata.
+			 */
+
+			int			one = 1;
+			bool		isNull;
+			Datum		valuesAtt[Natts_pg_attribute];
+			bool		nullsAtt[Natts_pg_attribute];
+			bool		replacesAtt[Natts_pg_attribute];
+			HeapTuple	newTup;
+
+			MemSet(valuesAtt, 0, sizeof(valuesAtt));
+			MemSet(nullsAtt, false, sizeof(nullsAtt));
+			MemSet(replacesAtt, false, sizeof(replacesAtt));
+
+			missingval = array_get_element(missingval,
+										   1,
+										   &one,
+										   0,
+										   attTup->attlen,
+										   attTup->attbyval,
+										   attTup->attalign,
+										   &isNull);
+			missingval = PointerGetDatum(construct_array(&missingval,
+														 1,
+														 targettype,
+														 tform->typlen,
+														 tform->typbyval,
+														 tform->typalign));
+
+			valuesAtt[Anum_pg_attribute_attmissingval - 1] = missingval;
+			replacesAtt[Anum_pg_attribute_attmissingval - 1] = true;
+			nullsAtt[Anum_pg_attribute_attmissingval - 1] = false;
+
+			newTup = heap_modify_tuple(heapTup, RelationGetDescr(attrelation),
+									   valuesAtt, nullsAtt, replacesAtt);
+			heap_freetuple(heapTup);
+			heapTup = newTup;
+			attTup = (Form_pg_attribute) GETSTRUCT(heapTup);
+		}
+	}
+
+	attTup->atttypid = targettype;
+	attTup->atttypmod = targettypmod;
+	attTup->attcollation = targetcollid;
+	attTup->attndims = list_length(typeName->arrayBounds);
+	attTup->attlen = tform->typlen;
+	attTup->attbyval = tform->typbyval;
+	attTup->attalign = tform->typalign;
+	attTup->attstorage = tform->typstorage;
+	attTup->attcompression = InvalidCompressionMethod;
+
+	ReleaseSysCache(typeTuple);
+
+	CatalogTupleUpdate(attrelation, &heapTup->t_self, heapTup);
+
+	table_close(attrelation, RowExclusiveLock);
+
+	/* Install dependencies on new datatype and collation */
+	add_column_datatype_dependency(RelationGetRelid(rel), attnum, targettype);
+	add_column_collation_dependency(RelationGetRelid(rel), attnum, targetcollid);
+
+	/*
+	 * Drop any pg_statistic entry for the column, since it's now wrong type
+	 */
+	RemoveStatistics(RelationGetRelid(rel), attnum);
+
+	InvokeObjectPostAlterHook(RelationRelationId,
+							  RelationGetRelid(rel), attnum);
+
+	/*
+	 * Update the default, if present, by brute force --- remove and re-add
+	 * the default.  Probably unsafe to take shortcuts, since the new version
+	 * may well have additional dependencies.  (It's okay to do this now,
+	 * rather than after other ALTER TYPE commands, since the default won't
+	 * depend on other column types.)
+	 */
+	if (defaultexpr)
+	{
+		/*
+		 * If it's a GENERATED default, drop its dependency records, in
+		 * particular its INTERNAL dependency on the column, which would
+		 * otherwise cause dependency.c to refuse to perform the deletion.
+		 */
+		if (attTup->attgenerated)
+		{
+			Oid			attrdefoid = GetAttrDefaultOid(RelationGetRelid(rel), attnum);
+
+			if (!OidIsValid(attrdefoid))
+				elog(ERROR, "could not find attrdef tuple for relation %u attnum %d",
+					 RelationGetRelid(rel), attnum);
+			(void) deleteDependencyRecordsFor(AttrDefaultRelationId, attrdefoid, false);
+		}
+
+		/*
+		 * Make updates-so-far visible, particularly the new pg_attribute row
+		 * which will be updated again.
+		 */
+		CommandCounterIncrement();
+
+		/*
+		 * We use RESTRICT here for safety, but at present we do not expect
+		 * anything to depend on the default.
+		 */
+		RemoveAttrDefault(RelationGetRelid(rel), attnum, DROP_RESTRICT, true,
+						  true);
+
+		StoreAttrDefault(rel, attnum, defaultexpr, true, false);
+	}
+
+	ObjectAddressSubSet(address, RelationRelationId,
+						RelationGetRelid(rel), attnum);
+
+	/* Cleanup */
+	heap_freetuple(heapTup);
+
+	return address;
+}
+
+/*
+ * Subroutine for ATExecAlterColumnType: remember that a replica identity
+ * needs to be reset.
+ */
+static void
+RememberReplicaIdentityForRebuilding(Oid indoid, AlteredTableInfo *tab)
+{
+	if (!get_index_isreplident(indoid))
+		return;
+
+	if (tab->replicaIdentityIndex)
+		elog(ERROR, "relation %u has multiple indexes marked as replica identity", tab->relid);
+
+	tab->replicaIdentityIndex = get_rel_name(indoid);
+}
+
+/*
+ * Subroutine for ATExecAlterColumnType: remember any clustered index.
+ */
+static void
+RememberClusterOnForRebuilding(Oid indoid, AlteredTableInfo *tab)
+{
+	if (!get_index_isclustered(indoid))
+		return;
+
+	if (tab->clusterOnIndex)
+		elog(ERROR, "relation %u has multiple clustered indexes", tab->relid);
+
+	tab->clusterOnIndex = get_rel_name(indoid);
+}
+
+/*
+ * Subroutine for ATExecAlterColumnType: remember that a constraint needs
+ * to be rebuilt (which we might already know).
+ */
+static void
+RememberConstraintForRebuilding(Oid conoid, AlteredTableInfo *tab)
+{
+	/*
+	 * This de-duplication check is critical for two independent reasons: we
+	 * mustn't try to recreate the same constraint twice, and if a constraint
+	 * depends on more than one column whose type is to be altered, we must
+	 * capture its definition string before applying any of the column type
+	 * changes.  ruleutils.c will get confused if we ask again later.
+	 */
+	if (!list_member_oid(tab->changedConstraintOids, conoid))
+	{
+		/* OK, capture the constraint's existing definition string */
+		char	   *defstring = pg_get_constraintdef_command(conoid);
+		Oid			indoid;
+
+		tab->changedConstraintOids = lappend_oid(tab->changedConstraintOids,
+												 conoid);
+		tab->changedConstraintDefs = lappend(tab->changedConstraintDefs,
+											 defstring);
+
+		/*
+		 * For the index of a constraint, if any, remember if it is used for
+		 * the table's replica identity or if it is a clustered index, so that
+		 * ATPostAlterTypeCleanup() can queue up commands necessary to restore
+		 * those properties.
+		 */
+		indoid = get_constraint_index(conoid);
+		if (OidIsValid(indoid))
+		{
+			RememberReplicaIdentityForRebuilding(indoid, tab);
+			RememberClusterOnForRebuilding(indoid, tab);
+		}
+	}
+}
+
+/*
+ * Subroutine for ATExecAlterColumnType: remember that an index needs
+ * to be rebuilt (which we might already know).
+ */
+static void
+RememberIndexForRebuilding(Oid indoid, AlteredTableInfo *tab)
+{
+	/*
+	 * This de-duplication check is critical for two independent reasons: we
+	 * mustn't try to recreate the same index twice, and if an index depends
+	 * on more than one column whose type is to be altered, we must capture
+	 * its definition string before applying any of the column type changes.
+	 * ruleutils.c will get confused if we ask again later.
+	 */
+	if (!list_member_oid(tab->changedIndexOids, indoid))
+	{
+		/*
+		 * Before adding it as an index-to-rebuild, we'd better see if it
+		 * belongs to a constraint, and if so rebuild the constraint instead.
+		 * Typically this check fails, because constraint indexes normally
+		 * have only dependencies on their constraint.  But it's possible for
+		 * such an index to also have direct dependencies on table columns,
+		 * for example with a partial exclusion constraint.
+		 */
+		Oid			conoid = get_index_constraint(indoid);
+
+		if (OidIsValid(conoid))
+		{
+			RememberConstraintForRebuilding(conoid, tab);
+		}
+		else
+		{
+			/* OK, capture the index's existing definition string */
+			char	   *defstring = pg_get_indexdef_string(indoid);
+
+			tab->changedIndexOids = lappend_oid(tab->changedIndexOids,
+												indoid);
+			tab->changedIndexDefs = lappend(tab->changedIndexDefs,
+											defstring);
+
+			/*
+			 * Remember if this index is used for the table's replica identity
+			 * or if it is a clustered index, so that ATPostAlterTypeCleanup()
+			 * can queue up commands necessary to restore those properties.
+			 */
+			RememberReplicaIdentityForRebuilding(indoid, tab);
+			RememberClusterOnForRebuilding(indoid, tab);
+		}
+	}
+}
+
+/*
+ * Subroutine for ATExecAlterColumnType: remember that a statistics object
+ * needs to be rebuilt (which we might already know).
+ */
+static void
+RememberStatisticsForRebuilding(Oid stxoid, AlteredTableInfo *tab)
+{
+	/*
+	 * This de-duplication check is critical for two independent reasons: we
+	 * mustn't try to recreate the same statistics object twice, and if the
+	 * statistics object depends on more than one column whose type is to be
+	 * altered, we must capture its definition string before applying any of
+	 * the type changes. ruleutils.c will get confused if we ask again later.
+	 */
+	if (!list_member_oid(tab->changedStatisticsOids, stxoid))
+	{
+		/* OK, capture the statistics object's existing definition string */
+		char	   *defstring = pg_get_statisticsobjdef_string(stxoid);
+
+		tab->changedStatisticsOids = lappend_oid(tab->changedStatisticsOids,
+												 stxoid);
+		tab->changedStatisticsDefs = lappend(tab->changedStatisticsDefs,
+											 defstring);
+	}
+}
+
+/*
+ * Cleanup after we've finished all the ALTER TYPE operations for a
+ * particular relation.  We have to drop and recreate all the indexes
+ * and constraints that depend on the altered columns.  We do the
+ * actual dropping here, but re-creation is managed by adding work
+ * queue entries to do those steps later.
+ */
+static void
+ATPostAlterTypeCleanup(List **wqueue, AlteredTableInfo *tab, LOCKMODE lockmode)
+{
+	ObjectAddress obj;
+	ObjectAddresses *objects;
+	ListCell   *def_item;
+	ListCell   *oid_item;
+
+	/*
+	 * Collect all the constraints and indexes to drop so we can process them
+	 * in a single call.  That way we don't have to worry about dependencies
+	 * among them.
+	 */
+	objects = new_object_addresses();
+
+	/*
+	 * Re-parse the index and constraint definitions, and attach them to the
+	 * appropriate work queue entries.  We do this before dropping because in
+	 * the case of a FOREIGN KEY constraint, we might not yet have exclusive
+	 * lock on the table the constraint is attached to, and we need to get
+	 * that before reparsing/dropping.
+	 *
+	 * We can't rely on the output of deparsing to tell us which relation to
+	 * operate on, because concurrent activity might have made the name
+	 * resolve differently.  Instead, we've got to use the OID of the
+	 * constraint or index we're processing to figure out which relation to
+	 * operate on.
+	 */
+	forboth(oid_item, tab->changedConstraintOids,
+			def_item, tab->changedConstraintDefs)
+	{
+		Oid			oldId = lfirst_oid(oid_item);
+		HeapTuple	tup;
+		Form_pg_constraint con;
+		Oid			relid;
+		Oid			confrelid;
+		char		contype;
+		bool		conislocal;
+
+		tup = SearchSysCache1(CONSTROID, ObjectIdGetDatum(oldId));
+		if (!HeapTupleIsValid(tup)) /* should not happen */
+			elog(ERROR, "cache lookup failed for constraint %u", oldId);
+		con = (Form_pg_constraint) GETSTRUCT(tup);
+		if (OidIsValid(con->conrelid))
+			relid = con->conrelid;
+		else
+		{
+			/* must be a domain constraint */
+			relid = get_typ_typrelid(getBaseType(con->contypid));
+			if (!OidIsValid(relid))
+				elog(ERROR, "could not identify relation associated with constraint %u", oldId);
+		}
+		confrelid = con->confrelid;
+		contype = con->contype;
+		conislocal = con->conislocal;
+		ReleaseSysCache(tup);
+
+		ObjectAddressSet(obj, ConstraintRelationId, oldId);
+		add_exact_object_address(&obj, objects);
+
+		/*
+		 * If the constraint is inherited (only), we don't want to inject a
+		 * new definition here; it'll get recreated when ATAddCheckConstraint
+		 * recurses from adding the parent table's constraint.  But we had to
+		 * carry the info this far so that we can drop the constraint below.
+		 */
+		if (!conislocal)
+			continue;
+
+		/*
+		 * When rebuilding an FK constraint that references the table we're
+		 * modifying, we might not yet have any lock on the FK's table, so get
+		 * one now.  We'll need AccessExclusiveLock for the DROP CONSTRAINT
+		 * step, so there's no value in asking for anything weaker.
+		 */
+		if (relid != tab->relid && contype == CONSTRAINT_FOREIGN)
+			LockRelationOid(relid, AccessExclusiveLock);
+
+		ATPostAlterTypeParse(oldId, relid, confrelid,
+							 (char *) lfirst(def_item),
+							 wqueue, lockmode, tab->rewrite);
+	}
+	forboth(oid_item, tab->changedIndexOids,
+			def_item, tab->changedIndexDefs)
+	{
+		Oid			oldId = lfirst_oid(oid_item);
+		Oid			relid;
+
+		relid = IndexGetRelation(oldId, false);
+		ATPostAlterTypeParse(oldId, relid, InvalidOid,
+							 (char *) lfirst(def_item),
+							 wqueue, lockmode, tab->rewrite);
+
+		ObjectAddressSet(obj, RelationRelationId, oldId);
+		add_exact_object_address(&obj, objects);
+	}
+
+	/* add dependencies for new statistics */
+	forboth(oid_item, tab->changedStatisticsOids,
+			def_item, tab->changedStatisticsDefs)
+	{
+		Oid			oldId = lfirst_oid(oid_item);
+		Oid			relid;
+
+		relid = StatisticsGetRelation(oldId, false);
+		ATPostAlterTypeParse(oldId, relid, InvalidOid,
+							 (char *) lfirst(def_item),
+							 wqueue, lockmode, tab->rewrite);
+
+		ObjectAddressSet(obj, StatisticExtRelationId, oldId);
+		add_exact_object_address(&obj, objects);
+	}
+
+	/*
+	 * Queue up command to restore replica identity index marking
+	 */
+	if (tab->replicaIdentityIndex)
+	{
+		AlterTableCmd *cmd = makeNode(AlterTableCmd);
+		ReplicaIdentityStmt *subcmd = makeNode(ReplicaIdentityStmt);
+
+		subcmd->identity_type = REPLICA_IDENTITY_INDEX;
+		subcmd->name = tab->replicaIdentityIndex;
+		cmd->subtype = AT_ReplicaIdentity;
+		cmd->def = (Node *) subcmd;
+
+		/* do it after indexes and constraints */
+		tab->subcmds[AT_PASS_OLD_CONSTR] =
+			lappend(tab->subcmds[AT_PASS_OLD_CONSTR], cmd);
+	}
+
+	/*
+	 * Queue up command to restore marking of index used for cluster.
+	 */
+	if (tab->clusterOnIndex)
+	{
+		AlterTableCmd *cmd = makeNode(AlterTableCmd);
+
+		cmd->subtype = AT_ClusterOn;
+		cmd->name = tab->clusterOnIndex;
+
+		/* do it after indexes and constraints */
+		tab->subcmds[AT_PASS_OLD_CONSTR] =
+			lappend(tab->subcmds[AT_PASS_OLD_CONSTR], cmd);
+	}
+
+	/*
+	 * It should be okay to use DROP_RESTRICT here, since nothing else should
+	 * be depending on these objects.
+	 */
+	performMultipleDeletions(objects, DROP_RESTRICT, PERFORM_DELETION_INTERNAL);
+
+	free_object_addresses(objects);
+
+	/*
+	 * The objects will get recreated during subsequent passes over the work
+	 * queue.
+	 */
+}
+
+/*
+ * Parse the previously-saved definition string for a constraint, index or
+ * statistics object against the newly-established column data type(s), and
+ * queue up the resulting command parsetrees for execution.
+ *
+ * This might fail if, for example, you have a WHERE clause that uses an
+ * operator that's not available for the new column type.
+ */
+static void
+ATPostAlterTypeParse(Oid oldId, Oid oldRelId, Oid refRelId, char *cmd,
+					 List **wqueue, LOCKMODE lockmode, bool rewrite)
+{
+	List	   *raw_parsetree_list;
+	List	   *querytree_list;
+	ListCell   *list_item;
+	Relation	rel;
+
+	/*
+	 * We expect that we will get only ALTER TABLE and CREATE INDEX
+	 * statements. Hence, there is no need to pass them through
+	 * parse_analyze_*() or the rewriter, but instead we need to pass them
+	 * through parse_utilcmd.c to make them ready for execution.
+	 */
+	raw_parsetree_list = raw_parser(cmd, RAW_PARSE_DEFAULT);
+	querytree_list = NIL;
+	foreach(list_item, raw_parsetree_list)
+	{
+		RawStmt    *rs = lfirst_node(RawStmt, list_item);
+		Node	   *stmt = rs->stmt;
+
+		if (IsA(stmt, IndexStmt))
+			querytree_list = lappend(querytree_list,
+									 transformIndexStmt(oldRelId,
+														(IndexStmt *) stmt,
+														cmd));
+		else if (IsA(stmt, AlterTableStmt))
+		{
+			List	   *beforeStmts;
+			List	   *afterStmts;
+
+			stmt = (Node *) transformAlterTableStmt(oldRelId,
+													(AlterTableStmt *) stmt,
+													cmd,
+													&beforeStmts,
+													&afterStmts);
+			querytree_list = list_concat(querytree_list, beforeStmts);
+			querytree_list = lappend(querytree_list, stmt);
+			querytree_list = list_concat(querytree_list, afterStmts);
+		}
+		else if (IsA(stmt, CreateStatsStmt))
+			querytree_list = lappend(querytree_list,
+									 transformStatsStmt(oldRelId,
+														(CreateStatsStmt *) stmt,
+														cmd));
+		else
+			querytree_list = lappend(querytree_list, stmt);
+	}
+
+	/* Caller should already have acquired whatever lock we need. */
+	rel = relation_open(oldRelId, NoLock);
+
+	/*
+	 * Attach each generated command to the proper place in the work queue.
+	 * Note this could result in creation of entirely new work-queue entries.
+	 *
+	 * Also note that we have to tweak the command subtypes, because it turns
+	 * out that re-creation of indexes and constraints has to act a bit
+	 * differently from initial creation.
+	 */
+	foreach(list_item, querytree_list)
+	{
+		Node	   *stm = (Node *) lfirst(list_item);
+		AlteredTableInfo *tab;
+
+		tab = ATGetQueueEntry(wqueue, rel);
+
+		if (IsA(stm, IndexStmt))
+		{
+			IndexStmt  *stmt = (IndexStmt *) stm;
+			AlterTableCmd *newcmd;
+
+			if (!rewrite)
+				TryReuseIndex(oldId, stmt);
+			stmt->reset_default_tblspc = true;
+			/* keep the index's comment */
+			stmt->idxcomment = GetComment(oldId, RelationRelationId, 0);
+
+			newcmd = makeNode(AlterTableCmd);
+			newcmd->subtype = AT_ReAddIndex;
+			newcmd->def = (Node *) stmt;
+			tab->subcmds[AT_PASS_OLD_INDEX] =
+				lappend(tab->subcmds[AT_PASS_OLD_INDEX], newcmd);
+		}
+		else if (IsA(stm, AlterTableStmt))
+		{
+			AlterTableStmt *stmt = (AlterTableStmt *) stm;
+			ListCell   *lcmd;
+
+			foreach(lcmd, stmt->cmds)
+			{
+				AlterTableCmd *cmd = lfirst_node(AlterTableCmd, lcmd);
+
+				if (cmd->subtype == AT_AddIndex)
+				{
+					IndexStmt  *indstmt;
+					Oid			indoid;
+
+					indstmt = castNode(IndexStmt, cmd->def);
+					indoid = get_constraint_index(oldId);
+
+					if (!rewrite)
+						TryReuseIndex(indoid, indstmt);
+					/* keep any comment on the index */
+					indstmt->idxcomment = GetComment(indoid,
+													 RelationRelationId, 0);
+					indstmt->reset_default_tblspc = true;
+
+					cmd->subtype = AT_ReAddIndex;
+					tab->subcmds[AT_PASS_OLD_INDEX] =
+						lappend(tab->subcmds[AT_PASS_OLD_INDEX], cmd);
+
+					/* recreate any comment on the constraint */
+					RebuildConstraintComment(tab,
+											 AT_PASS_OLD_INDEX,
+											 oldId,
+											 rel,
+											 NIL,
+											 indstmt->idxname);
+				}
+				else if (cmd->subtype == AT_AddConstraint)
+				{
+					Constraint *con = castNode(Constraint, cmd->def);
+
+					con->old_pktable_oid = refRelId;
+					/* rewriting neither side of a FK */
+					if (con->contype == CONSTR_FOREIGN &&
+						!rewrite && tab->rewrite == 0)
+						TryReuseForeignKey(oldId, con);
+					con->reset_default_tblspc = true;
+					cmd->subtype = AT_ReAddConstraint;
+					tab->subcmds[AT_PASS_OLD_CONSTR] =
+						lappend(tab->subcmds[AT_PASS_OLD_CONSTR], cmd);
+
+					/* recreate any comment on the constraint */
+					RebuildConstraintComment(tab,
+											 AT_PASS_OLD_CONSTR,
+											 oldId,
+											 rel,
+											 NIL,
+											 con->conname);
+				}
+				else if (cmd->subtype == AT_SetNotNull)
+				{
+					/*
+					 * The parser will create AT_SetNotNull subcommands for
+					 * columns of PRIMARY KEY indexes/constraints, but we need
+					 * not do anything with them here, because the columns'
+					 * NOT NULL marks will already have been propagated into
+					 * the new table definition.
+					 */
+				}
+				else
+					elog(ERROR, "unexpected statement subtype: %d",
+						 (int) cmd->subtype);
+			}
+		}
+		else if (IsA(stm, AlterDomainStmt))
+		{
+			AlterDomainStmt *stmt = (AlterDomainStmt *) stm;
+
+			if (stmt->subtype == 'C')	/* ADD CONSTRAINT */
+			{
+				Constraint *con = castNode(Constraint, stmt->def);
+				AlterTableCmd *cmd = makeNode(AlterTableCmd);
+
+				cmd->subtype = AT_ReAddDomainConstraint;
+				cmd->def = (Node *) stmt;
+				tab->subcmds[AT_PASS_OLD_CONSTR] =
+					lappend(tab->subcmds[AT_PASS_OLD_CONSTR], cmd);
+
+				/* recreate any comment on the constraint */
+				RebuildConstraintComment(tab,
+										 AT_PASS_OLD_CONSTR,
+										 oldId,
+										 NULL,
+										 stmt->typeName,
+										 con->conname);
+			}
+			else
+				elog(ERROR, "unexpected statement subtype: %d",
+					 (int) stmt->subtype);
+		}
+		else if (IsA(stm, CreateStatsStmt))
+		{
+			CreateStatsStmt *stmt = (CreateStatsStmt *) stm;
+			AlterTableCmd *newcmd;
+
+			/* keep the statistics object's comment */
+			stmt->stxcomment = GetComment(oldId, StatisticExtRelationId, 0);
+
+			newcmd = makeNode(AlterTableCmd);
+			newcmd->subtype = AT_ReAddStatistics;
+			newcmd->def = (Node *) stmt;
+			tab->subcmds[AT_PASS_MISC] =
+				lappend(tab->subcmds[AT_PASS_MISC], newcmd);
+		}
+		else
+			elog(ERROR, "unexpected statement type: %d",
+				 (int) nodeTag(stm));
+	}
+
+	relation_close(rel, NoLock);
+}
+
+/*
+ * Subroutine for ATPostAlterTypeParse() to recreate any existing comment
+ * for a table or domain constraint that is being rebuilt.
+ *
+ * objid is the OID of the constraint.
+ * Pass "rel" for a table constraint, or "domname" (domain's qualified name
+ * as a string list) for a domain constraint.
+ * (We could dig that info, as well as the conname, out of the pg_constraint
+ * entry; but callers already have them so might as well pass them.)
+ */
+static void
+RebuildConstraintComment(AlteredTableInfo *tab, int pass, Oid objid,
+						 Relation rel, List *domname,
+						 const char *conname)
+{
+	CommentStmt *cmd;
+	char	   *comment_str;
+	AlterTableCmd *newcmd;
+
+	/* Look for comment for object wanted, and leave if none */
+	comment_str = GetComment(objid, ConstraintRelationId, 0);
+	if (comment_str == NULL)
+		return;
+
+	/* Build CommentStmt node, copying all input data for safety */
+	cmd = makeNode(CommentStmt);
+	if (rel)
+	{
+		cmd->objtype = OBJECT_TABCONSTRAINT;
+		cmd->object = (Node *)
+			list_make3(makeString(get_namespace_name(RelationGetNamespace(rel))),
+					   makeString(pstrdup(RelationGetRelationName(rel))),
+					   makeString(pstrdup(conname)));
+	}
+	else
+	{
+		cmd->objtype = OBJECT_DOMCONSTRAINT;
+		cmd->object = (Node *)
+			list_make2(makeTypeNameFromNameList(copyObject(domname)),
+					   makeString(pstrdup(conname)));
+	}
+	cmd->comment = comment_str;
+
+	/* Append it to list of commands */
+	newcmd = makeNode(AlterTableCmd);
+	newcmd->subtype = AT_ReAddComment;
+	newcmd->def = (Node *) cmd;
+	tab->subcmds[pass] = lappend(tab->subcmds[pass], newcmd);
+}
+
+/*
+ * Subroutine for ATPostAlterTypeParse().  Calls out to CheckIndexCompatible()
+ * for the real analysis, then mutates the IndexStmt based on that verdict.
+ */
+static void
+TryReuseIndex(Oid oldId, IndexStmt *stmt)
+{
+	if (CheckIndexCompatible(oldId,
+							 stmt->accessMethod,
+							 stmt->indexParams,
+							 stmt->excludeOpNames))
+	{
+		Relation	irel = index_open(oldId, NoLock);
+
+		/* If it's a partitioned index, there is no storage to share. */
+		if (irel->rd_rel->relkind != RELKIND_PARTITIONED_INDEX)
+		{
+			stmt->oldNode = irel->rd_node.relNode;
+			stmt->oldCreateSubid = irel->rd_createSubid;
+			stmt->oldFirstRelfilenodeSubid = irel->rd_firstRelfilenodeSubid;
+		}
+		index_close(irel, NoLock);
+	}
+}
+
+/*
+ * Subroutine for ATPostAlterTypeParse().
+ *
+ * Stash the old P-F equality operator into the Constraint node, for possible
+ * use by ATAddForeignKeyConstraint() in determining whether revalidation of
+ * this constraint can be skipped.
+ */
+static void
+TryReuseForeignKey(Oid oldId, Constraint *con)
+{
+	HeapTuple	tup;
+	Datum		adatum;
+	bool		isNull;
+	ArrayType  *arr;
+	Oid		   *rawarr;
+	int			numkeys;
+	int			i;
+
+	Assert(con->contype == CONSTR_FOREIGN);
+	Assert(con->old_conpfeqop == NIL);	/* already prepared this node */
+
+	tup = SearchSysCache1(CONSTROID, ObjectIdGetDatum(oldId));
+	if (!HeapTupleIsValid(tup)) /* should not happen */
+		elog(ERROR, "cache lookup failed for constraint %u", oldId);
+
+	adatum = SysCacheGetAttr(CONSTROID, tup,
+							 Anum_pg_constraint_conpfeqop, &isNull);
+	if (isNull)
+		elog(ERROR, "null conpfeqop for constraint %u", oldId);
+	arr = DatumGetArrayTypeP(adatum);	/* ensure not toasted */
+	numkeys = ARR_DIMS(arr)[0];
+	/* test follows the one in ri_FetchConstraintInfo() */
+	if (ARR_NDIM(arr) != 1 ||
+		ARR_HASNULL(arr) ||
+		ARR_ELEMTYPE(arr) != OIDOID)
+		elog(ERROR, "conpfeqop is not a 1-D Oid array");
+	rawarr = (Oid *) ARR_DATA_PTR(arr);
+
+	/* stash a List of the operator Oids in our Constraint node */
+	for (i = 0; i < numkeys; i++)
+		con->old_conpfeqop = lappend_oid(con->old_conpfeqop, rawarr[i]);
+
+	ReleaseSysCache(tup);
+}
+
+/*
+ * ALTER COLUMN .. OPTIONS ( ... )
+ *
+ * Returns the address of the modified column
+ */
+static ObjectAddress
+ATExecAlterColumnGenericOptions(Relation rel,
+								const char *colName,
+								List *options,
+								LOCKMODE lockmode)
+{
+	Relation	ftrel;
+	Relation	attrel;
+	ForeignServer *server;
+	ForeignDataWrapper *fdw;
+	HeapTuple	tuple;
+	HeapTuple	newtuple;
+	bool		isnull;
+	Datum		repl_val[Natts_pg_attribute];
+	bool		repl_null[Natts_pg_attribute];
+	bool		repl_repl[Natts_pg_attribute];
+	Datum		datum;
+	Form_pg_foreign_table fttableform;
+	Form_pg_attribute atttableform;
+	AttrNumber	attnum;
+	ObjectAddress address;
+
+	if (options == NIL)
+		return InvalidObjectAddress;
+
+	/* First, determine FDW validator associated to the foreign table. */
+	ftrel = table_open(ForeignTableRelationId, AccessShareLock);
+	tuple = SearchSysCache1(FOREIGNTABLEREL, rel->rd_id);
+	if (!HeapTupleIsValid(tuple))
+		ereport(ERROR,
+				(errcode(ERRCODE_UNDEFINED_OBJECT),
+				 errmsg("foreign table \"%s\" does not exist",
+						RelationGetRelationName(rel))));
+	fttableform = (Form_pg_foreign_table) GETSTRUCT(tuple);
+	server = GetForeignServer(fttableform->ftserver);
+	fdw = GetForeignDataWrapper(server->fdwid);
+
+	table_close(ftrel, AccessShareLock);
+	ReleaseSysCache(tuple);
+
+	attrel = table_open(AttributeRelationId, RowExclusiveLock);
+	tuple = SearchSysCacheAttName(RelationGetRelid(rel), colName);
+	if (!HeapTupleIsValid(tuple))
+		ereport(ERROR,
+				(errcode(ERRCODE_UNDEFINED_COLUMN),
+				 errmsg("column \"%s\" of relation \"%s\" does not exist",
+						colName, RelationGetRelationName(rel))));
+
+	/* Prevent them from altering a system attribute */
+	atttableform = (Form_pg_attribute) GETSTRUCT(tuple);
+	attnum = atttableform->attnum;
+	if (attnum <= 0)
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("cannot alter system column \"%s\"", colName)));
+
+
+	/* Initialize buffers for new tuple values */
+	memset(repl_val, 0, sizeof(repl_val));
+	memset(repl_null, false, sizeof(repl_null));
+	memset(repl_repl, false, sizeof(repl_repl));
+
+	/* Extract the current options */
+	datum = SysCacheGetAttr(ATTNAME,
+							tuple,
+							Anum_pg_attribute_attfdwoptions,
+							&isnull);
+	if (isnull)
+		datum = PointerGetDatum(NULL);
+
+	/* Transform the options */
+	datum = transformGenericOptions(AttributeRelationId,
+									datum,
+									options,
+									fdw->fdwvalidator);
+
+	if (PointerIsValid(DatumGetPointer(datum)))
+		repl_val[Anum_pg_attribute_attfdwoptions - 1] = datum;
+	else
+		repl_null[Anum_pg_attribute_attfdwoptions - 1] = true;
+
+	repl_repl[Anum_pg_attribute_attfdwoptions - 1] = true;
+
+	/* Everything looks good - update the tuple */
+
+	newtuple = heap_modify_tuple(tuple, RelationGetDescr(attrel),
+								 repl_val, repl_null, repl_repl);
+
+	CatalogTupleUpdate(attrel, &newtuple->t_self, newtuple);
+
+	InvokeObjectPostAlterHook(RelationRelationId,
+							  RelationGetRelid(rel),
+							  atttableform->attnum);
+	ObjectAddressSubSet(address, RelationRelationId,
+						RelationGetRelid(rel), attnum);
+
+	ReleaseSysCache(tuple);
+
+	table_close(attrel, RowExclusiveLock);
+
+	heap_freetuple(newtuple);
+
+	return address;
+}
+
+/*
+ * ALTER TABLE OWNER
+ *
+ * recursing is true if we are recursing from a table to its indexes,
+ * sequences, or toast table.  We don't allow the ownership of those things to
+ * be changed separately from the parent table.  Also, we can skip permission
+ * checks (this is necessary not just an optimization, else we'd fail to
+ * handle toast tables properly).
+ *
+ * recursing is also true if ALTER TYPE OWNER is calling us to fix up a
+ * free-standing composite type.
+ */
+void
+ATExecChangeOwner(Oid relationOid, Oid newOwnerId, bool recursing, LOCKMODE lockmode)
+{
+	Relation	target_rel;
+	Relation	class_rel;
+	HeapTuple	tuple;
+	Form_pg_class tuple_class;
+
+	/*
+	 * Get exclusive lock till end of transaction on the target table. Use
+	 * relation_open so that we can work on indexes and sequences.
+	 */
+	target_rel = relation_open(relationOid, lockmode);
+
+	/* Get its pg_class tuple, too */
+	class_rel = table_open(RelationRelationId, RowExclusiveLock);
+
+	tuple = SearchSysCache1(RELOID, ObjectIdGetDatum(relationOid));
+	if (!HeapTupleIsValid(tuple))
+		elog(ERROR, "cache lookup failed for relation %u", relationOid);
+	tuple_class = (Form_pg_class) GETSTRUCT(tuple);
+
+	/* Can we change the ownership of this tuple? */
+	switch (tuple_class->relkind)
+	{
+		case RELKIND_RELATION:
+		case RELKIND_VIEW:
+		case RELKIND_MATVIEW:
+		case RELKIND_FOREIGN_TABLE:
+		case RELKIND_PARTITIONED_TABLE:
+			/* ok to change owner */
+			break;
+		case RELKIND_INDEX:
+			if (!recursing)
+			{
+				/*
+				 * Because ALTER INDEX OWNER used to be allowed, and in fact
+				 * is generated by old versions of pg_dump, we give a warning
+				 * and do nothing rather than erroring out.  Also, to avoid
+				 * unnecessary chatter while restoring those old dumps, say
+				 * nothing at all if the command would be a no-op anyway.
+				 */
+				if (tuple_class->relowner != newOwnerId)
+					ereport(WARNING,
+							(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+							 errmsg("cannot change owner of index \"%s\"",
+									NameStr(tuple_class->relname)),
+							 errhint("Change the ownership of the index's table, instead.")));
+				/* quick hack to exit via the no-op path */
+				newOwnerId = tuple_class->relowner;
+			}
+			break;
+		case RELKIND_PARTITIONED_INDEX:
+			if (recursing)
+				break;
+			ereport(ERROR,
+					(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+					 errmsg("cannot change owner of index \"%s\"",
+							NameStr(tuple_class->relname)),
+					 errhint("Change the ownership of the index's table, instead.")));
+			break;
+		case RELKIND_SEQUENCE:
+			if (!recursing &&
+				tuple_class->relowner != newOwnerId)
+			{
+				/* if it's an owned sequence, disallow changing it by itself */
+				Oid			tableId;
+				int32		colId;
+
+				if (sequenceIsOwned(relationOid, DEPENDENCY_AUTO, &tableId, &colId) ||
+					sequenceIsOwned(relationOid, DEPENDENCY_INTERNAL, &tableId, &colId))
+					ereport(ERROR,
+							(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+							 errmsg("cannot change owner of sequence \"%s\"",
+									NameStr(tuple_class->relname)),
+							 errdetail("Sequence \"%s\" is linked to table \"%s\".",
+									   NameStr(tuple_class->relname),
+									   get_rel_name(tableId))));
+			}
+			break;
+		case RELKIND_COMPOSITE_TYPE:
+			if (recursing)
+				break;
+			ereport(ERROR,
+					(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+					 errmsg("\"%s\" is a composite type",
+							NameStr(tuple_class->relname)),
+					 errhint("Use ALTER TYPE instead.")));
+			break;
+		case RELKIND_TOASTVALUE:
+			if (recursing)
+				break;
+			/* FALL THRU */
+		default:
+			ereport(ERROR,
+					(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+					 errmsg("cannot change owner of relation \"%s\"",
+							NameStr(tuple_class->relname)),
+					 errdetail_relkind_not_supported(tuple_class->relkind)));
+	}
+
+	/*
+	 * If the new owner is the same as the existing owner, consider the
+	 * command to have succeeded.  This is for dump restoration purposes.
+	 */
+	if (tuple_class->relowner != newOwnerId)
+	{
+		Datum		repl_val[Natts_pg_class];
+		bool		repl_null[Natts_pg_class];
+		bool		repl_repl[Natts_pg_class];
+		Acl		   *newAcl;
+		Datum		aclDatum;
+		bool		isNull;
+		HeapTuple	newtuple;
+
+		/* skip permission checks when recursing to index or toast table */
+		if (!recursing)
+		{
+			/* Superusers can always do it */
+			if (!superuser())
+			{
+				Oid			namespaceOid = tuple_class->relnamespace;
+				AclResult	aclresult;
+
+				/* Otherwise, must be owner of the existing object */
+				if (!pg_class_ownercheck(relationOid, GetUserId()))
+					aclcheck_error(ACLCHECK_NOT_OWNER, get_relkind_objtype(get_rel_relkind(relationOid)),
+								   RelationGetRelationName(target_rel));
+
+				/* Must be able to become new owner */
+				check_is_member_of_role(GetUserId(), newOwnerId);
+
+				/* New owner must have CREATE privilege on namespace */
+				aclresult = pg_namespace_aclcheck(namespaceOid, newOwnerId,
+												  ACL_CREATE);
+				if (aclresult != ACLCHECK_OK)
+					aclcheck_error(aclresult, OBJECT_SCHEMA,
+								   get_namespace_name(namespaceOid));
+			}
+		}
+
+		memset(repl_null, false, sizeof(repl_null));
+		memset(repl_repl, false, sizeof(repl_repl));
+
+		repl_repl[Anum_pg_class_relowner - 1] = true;
+		repl_val[Anum_pg_class_relowner - 1] = ObjectIdGetDatum(newOwnerId);
+
+		/*
+		 * Determine the modified ACL for the new owner.  This is only
+		 * necessary when the ACL is non-null.
+		 */
+		aclDatum = SysCacheGetAttr(RELOID, tuple,
+								   Anum_pg_class_relacl,
+								   &isNull);
+		if (!isNull)
+		{
+			newAcl = aclnewowner(DatumGetAclP(aclDatum),
+								 tuple_class->relowner, newOwnerId);
+			repl_repl[Anum_pg_class_relacl - 1] = true;
+			repl_val[Anum_pg_class_relacl - 1] = PointerGetDatum(newAcl);
+		}
+
+		newtuple = heap_modify_tuple(tuple, RelationGetDescr(class_rel), repl_val, repl_null, repl_repl);
+
+		CatalogTupleUpdate(class_rel, &newtuple->t_self, newtuple);
+
+		heap_freetuple(newtuple);
+
+		/*
+		 * We must similarly update any per-column ACLs to reflect the new
+		 * owner; for neatness reasons that's split out as a subroutine.
+		 */
+		change_owner_fix_column_acls(relationOid,
+									 tuple_class->relowner,
+									 newOwnerId);
+
+		/*
+		 * Update owner dependency reference, if any.  A composite type has
+		 * none, because it's tracked for the pg_type entry instead of here;
+		 * indexes and TOAST tables don't have their own entries either.
+		 */
+		if (tuple_class->relkind != RELKIND_COMPOSITE_TYPE &&
+			tuple_class->relkind != RELKIND_INDEX &&
+			tuple_class->relkind != RELKIND_PARTITIONED_INDEX &&
+			tuple_class->relkind != RELKIND_TOASTVALUE)
+			changeDependencyOnOwner(RelationRelationId, relationOid,
+									newOwnerId);
+
+		/*
+		 * Also change the ownership of the table's row type, if it has one
+		 */
+		if (OidIsValid(tuple_class->reltype))
+			AlterTypeOwnerInternal(tuple_class->reltype, newOwnerId);
+
+		/*
+		 * If we are operating on a table or materialized view, also change
+		 * the ownership of any indexes and sequences that belong to the
+		 * relation, as well as its toast table (if it has one).
+		 */
+		if (tuple_class->relkind == RELKIND_RELATION ||
+			tuple_class->relkind == RELKIND_PARTITIONED_TABLE ||
+			tuple_class->relkind == RELKIND_MATVIEW ||
+			tuple_class->relkind == RELKIND_TOASTVALUE)
+		{
+			List	   *index_oid_list;
+			ListCell   *i;
+
+			/* Find all the indexes belonging to this relation */
+			index_oid_list = RelationGetIndexList(target_rel);
+
+			/* For each index, recursively change its ownership */
+			foreach(i, index_oid_list)
+				ATExecChangeOwner(lfirst_oid(i), newOwnerId, true, lockmode);
+
+			list_free(index_oid_list);
+		}
+
+		/* If it has a toast table, recurse to change its ownership */
+		if (tuple_class->reltoastrelid != InvalidOid)
+			ATExecChangeOwner(tuple_class->reltoastrelid, newOwnerId,
+							  true, lockmode);
+
+		/* If it has dependent sequences, recurse to change them too */
+		change_owner_recurse_to_sequences(relationOid, newOwnerId, lockmode);
+	}
+
+	InvokeObjectPostAlterHook(RelationRelationId, relationOid, 0);
+
+	ReleaseSysCache(tuple);
+	table_close(class_rel, RowExclusiveLock);
+	relation_close(target_rel, NoLock);
+}
+
+/*
+ * change_owner_fix_column_acls
+ *
+ * Helper function for ATExecChangeOwner.  Scan the columns of the table
+ * and fix any non-null column ACLs to reflect the new owner.
+ */
+static void
+change_owner_fix_column_acls(Oid relationOid, Oid oldOwnerId, Oid newOwnerId)
+{
+	Relation	attRelation;
+	SysScanDesc scan;
+	ScanKeyData key[1];
+	HeapTuple	attributeTuple;
+
+	attRelation = table_open(AttributeRelationId, RowExclusiveLock);
+	ScanKeyInit(&key[0],
+				Anum_pg_attribute_attrelid,
+				BTEqualStrategyNumber, F_OIDEQ,
+				ObjectIdGetDatum(relationOid));
+	scan = systable_beginscan(attRelation, AttributeRelidNumIndexId,
+							  true, NULL, 1, key);
+	while (HeapTupleIsValid(attributeTuple = systable_getnext(scan)))
+	{
+		Form_pg_attribute att = (Form_pg_attribute) GETSTRUCT(attributeTuple);
+		Datum		repl_val[Natts_pg_attribute];
+		bool		repl_null[Natts_pg_attribute];
+		bool		repl_repl[Natts_pg_attribute];
+		Acl		   *newAcl;
+		Datum		aclDatum;
+		bool		isNull;
+		HeapTuple	newtuple;
+
+		/* Ignore dropped columns */
+		if (att->attisdropped)
+			continue;
+
+		aclDatum = heap_getattr(attributeTuple,
+								Anum_pg_attribute_attacl,
+								RelationGetDescr(attRelation),
+								&isNull);
+		/* Null ACLs do not require changes */
+		if (isNull)
+			continue;
+
+		memset(repl_null, false, sizeof(repl_null));
+		memset(repl_repl, false, sizeof(repl_repl));
+
+		newAcl = aclnewowner(DatumGetAclP(aclDatum),
+							 oldOwnerId, newOwnerId);
+		repl_repl[Anum_pg_attribute_attacl - 1] = true;
+		repl_val[Anum_pg_attribute_attacl - 1] = PointerGetDatum(newAcl);
+
+		newtuple = heap_modify_tuple(attributeTuple,
+									 RelationGetDescr(attRelation),
+									 repl_val, repl_null, repl_repl);
+
+		CatalogTupleUpdate(attRelation, &newtuple->t_self, newtuple);
+
+		heap_freetuple(newtuple);
+	}
+	systable_endscan(scan);
+	table_close(attRelation, RowExclusiveLock);
+}
+
+/*
+ * change_owner_recurse_to_sequences
+ *
+ * Helper function for ATExecChangeOwner.  Examines pg_depend searching
+ * for sequences that are dependent on serial columns, and changes their
+ * ownership.
+ */
+static void
+change_owner_recurse_to_sequences(Oid relationOid, Oid newOwnerId, LOCKMODE lockmode)
+{
+	Relation	depRel;
+	SysScanDesc scan;
+	ScanKeyData key[2];
+	HeapTuple	tup;
+
+	/*
+	 * SERIAL sequences are those having an auto dependency on one of the
+	 * table's columns (we don't care *which* column, exactly).
+	 */
+	depRel = table_open(DependRelationId, AccessShareLock);
+
+	ScanKeyInit(&key[0],
+				Anum_pg_depend_refclassid,
+				BTEqualStrategyNumber, F_OIDEQ,
+				ObjectIdGetDatum(RelationRelationId));
+	ScanKeyInit(&key[1],
+				Anum_pg_depend_refobjid,
+				BTEqualStrategyNumber, F_OIDEQ,
+				ObjectIdGetDatum(relationOid));
+	/* we leave refobjsubid unspecified */
+
+	scan = systable_beginscan(depRel, DependReferenceIndexId, true,
+							  NULL, 2, key);
+
+	while (HeapTupleIsValid(tup = systable_getnext(scan)))
+	{
+		Form_pg_depend depForm = (Form_pg_depend) GETSTRUCT(tup);
+		Relation	seqRel;
+
+		/* skip dependencies other than auto dependencies on columns */
+		if (depForm->refobjsubid == 0 ||
+			depForm->classid != RelationRelationId ||
+			depForm->objsubid != 0 ||
+			!(depForm->deptype == DEPENDENCY_AUTO || depForm->deptype == DEPENDENCY_INTERNAL))
+			continue;
+
+		/* Use relation_open just in case it's an index */
+		seqRel = relation_open(depForm->objid, lockmode);
+
+		/* skip non-sequence relations */
+		if (RelationGetForm(seqRel)->relkind != RELKIND_SEQUENCE)
+		{
+			/* No need to keep the lock */
+			relation_close(seqRel, lockmode);
+			continue;
+		}
+
+		/* We don't need to close the sequence while we alter it. */
+		ATExecChangeOwner(depForm->objid, newOwnerId, true, lockmode);
+
+		/* Now we can close it.  Keep the lock till end of transaction. */
+		relation_close(seqRel, NoLock);
+	}
+
+	systable_endscan(scan);
+
+	relation_close(depRel, AccessShareLock);
+}
+
+/*
+ * ALTER TABLE CLUSTER ON
+ *
+ * The only thing we have to do is to change the indisclustered bits.
+ *
+ * Return the address of the new clustering index.
+ */
+static ObjectAddress
+ATExecClusterOn(Relation rel, const char *indexName, LOCKMODE lockmode)
+{
+	Oid			indexOid;
+	ObjectAddress address;
+
+	indexOid = get_relname_relid(indexName, rel->rd_rel->relnamespace);
+
+	if (!OidIsValid(indexOid))
+		ereport(ERROR,
+				(errcode(ERRCODE_UNDEFINED_OBJECT),
+				 errmsg("index \"%s\" for table \"%s\" does not exist",
+						indexName, RelationGetRelationName(rel))));
+
+	/* Check index is valid to cluster on */
+	check_index_is_clusterable(rel, indexOid, lockmode);
+
+	/* And do the work */
+	mark_index_clustered(rel, indexOid, false);
+
+	ObjectAddressSet(address,
+					 RelationRelationId, indexOid);
+
+	return address;
+}
+
+/*
+ * ALTER TABLE SET WITHOUT CLUSTER
+ *
+ * We have to find any indexes on the table that have indisclustered bit
+ * set and turn it off.
+ */
+static void
+ATExecDropCluster(Relation rel, LOCKMODE lockmode)
+{
+	mark_index_clustered(rel, InvalidOid, false);
+}
+
+/*
+ * Preparation phase for SET ACCESS METHOD
+ *
+ * Check that access method exists.  If it is the same as the table's current
+ * access method, it is a no-op.  Otherwise, a table rewrite is necessary.
+ */
+static void
+ATPrepSetAccessMethod(AlteredTableInfo *tab, Relation rel, const char *amname)
+{
+	Oid			amoid;
+
+	/* Check that the table access method exists */
+	amoid = get_table_am_oid(amname, false);
+
+	if (rel->rd_rel->relam == amoid)
+		return;
+
+	/* Save info for Phase 3 to do the real work */
+	tab->rewrite |= AT_REWRITE_ACCESS_METHOD;
+	tab->newAccessMethod = amoid;
+}
+
+/*
+ * ALTER TABLE SET TABLESPACE
+ */
+static void
+ATPrepSetTableSpace(AlteredTableInfo *tab, Relation rel, const char *tablespacename, LOCKMODE lockmode)
+{
+	Oid			tablespaceId;
+
+	/* Check that the tablespace exists */
+	tablespaceId = get_tablespace_oid(tablespacename, false);
+
+	/* Check permissions except when moving to database's default */
+	if (OidIsValid(tablespaceId) && tablespaceId != MyDatabaseTableSpace)
+	{
+		AclResult	aclresult;
+
+		aclresult = pg_tablespace_aclcheck(tablespaceId, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE, tablespacename);
+	}
+
+	/* Save info for Phase 3 to do the real work */
+	if (OidIsValid(tab->newTableSpace))
+		ereport(ERROR,
+				(errcode(ERRCODE_SYNTAX_ERROR),
+				 errmsg("cannot have multiple SET TABLESPACE subcommands")));
+
+	tab->newTableSpace = tablespaceId;
+}
+
+/*
+ * Set, reset, or replace reloptions.
+ */
+static void
+ATExecSetRelOptions(Relation rel, List *defList, AlterTableType operation,
+					LOCKMODE lockmode)
+{
+	Oid			relid;
+	Relation	pgclass;
+	HeapTuple	tuple;
+	HeapTuple	newtuple;
+	Datum		datum;
+	bool		isnull;
+	Datum		newOptions;
+	Datum		repl_val[Natts_pg_class];
+	bool		repl_null[Natts_pg_class];
+	bool		repl_repl[Natts_pg_class];
+	static char *validnsps[] = HEAP_RELOPT_NAMESPACES;
+
+	if (defList == NIL && operation != AT_ReplaceRelOptions)
+		return;					/* nothing to do */
+
+	pgclass = table_open(RelationRelationId, RowExclusiveLock);
+
+	/* Fetch heap tuple */
+	relid = RelationGetRelid(rel);
+	tuple = SearchSysCache1(RELOID, ObjectIdGetDatum(relid));
+	if (!HeapTupleIsValid(tuple))
+		elog(ERROR, "cache lookup failed for relation %u", relid);
+
+	if (operation == AT_ReplaceRelOptions)
+	{
+		/*
+		 * If we're supposed to replace the reloptions list, we just pretend
+		 * there were none before.
+		 */
+		datum = (Datum) 0;
+		isnull = true;
+	}
+	else
+	{
+		/* Get the old reloptions */
+		datum = SysCacheGetAttr(RELOID, tuple, Anum_pg_class_reloptions,
+								&isnull);
+	}
+
+	/* Generate new proposed reloptions (text array) */
+	newOptions = transformRelOptions(isnull ? (Datum) 0 : datum,
+									 defList, NULL, validnsps, false,
+									 operation == AT_ResetRelOptions);
+
+	/* Validate */
+	switch (rel->rd_rel->relkind)
+	{
+		case RELKIND_RELATION:
+		case RELKIND_TOASTVALUE:
+		case RELKIND_MATVIEW:
+			(void) heap_reloptions(rel->rd_rel->relkind, newOptions, true);
+			break;
+		case RELKIND_PARTITIONED_TABLE:
+			(void) partitioned_table_reloptions(newOptions, true);
+			break;
+		case RELKIND_VIEW:
+			(void) view_reloptions(newOptions, true);
+			break;
+		case RELKIND_INDEX:
+		case RELKIND_PARTITIONED_INDEX:
+			(void) index_reloptions(rel->rd_indam->amoptions, newOptions, true);
+			break;
+		default:
+			ereport(ERROR,
+					(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+					 errmsg("cannot set options for relation \"%s\"",
+							RelationGetRelationName(rel)),
+					 errdetail_relkind_not_supported(rel->rd_rel->relkind)));
+			break;
+	}
+
+	/* Special-case validation of view options */
+	if (rel->rd_rel->relkind == RELKIND_VIEW)
+	{
+		Query	   *view_query = get_view_query(rel);
+		List	   *view_options = untransformRelOptions(newOptions);
+		ListCell   *cell;
+		bool		check_option = false;
+
+		foreach(cell, view_options)
+		{
+			DefElem    *defel = (DefElem *) lfirst(cell);
+
+			if (strcmp(defel->defname, "check_option") == 0)
+				check_option = true;
+		}
+
+		/*
+		 * If the check option is specified, look to see if the view is
+		 * actually auto-updatable or not.
+		 */
+		if (check_option)
+		{
+			const char *view_updatable_error =
+			view_query_is_auto_updatable(view_query, true);
+
+			if (view_updatable_error)
+				ereport(ERROR,
+						(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+						 errmsg("WITH CHECK OPTION is supported only on automatically updatable views"),
+						 errhint("%s", _(view_updatable_error))));
+		}
+	}
+
+	/*
+	 * All we need do here is update the pg_class row; the new options will be
+	 * propagated into relcaches during post-commit cache inval.
+	 */
+	memset(repl_val, 0, sizeof(repl_val));
+	memset(repl_null, false, sizeof(repl_null));
+	memset(repl_repl, false, sizeof(repl_repl));
+
+	if (newOptions != (Datum) 0)
+		repl_val[Anum_pg_class_reloptions - 1] = newOptions;
+	else
+		repl_null[Anum_pg_class_reloptions - 1] = true;
+
+	repl_repl[Anum_pg_class_reloptions - 1] = true;
+
+	newtuple = heap_modify_tuple(tuple, RelationGetDescr(pgclass),
+								 repl_val, repl_null, repl_repl);
+
+	CatalogTupleUpdate(pgclass, &newtuple->t_self, newtuple);
+
+	InvokeObjectPostAlterHook(RelationRelationId, RelationGetRelid(rel), 0);
+
+	heap_freetuple(newtuple);
+
+	ReleaseSysCache(tuple);
+
+	/* repeat the whole exercise for the toast table, if there's one */
+	if (OidIsValid(rel->rd_rel->reltoastrelid))
+	{
+		Relation	toastrel;
+		Oid			toastid = rel->rd_rel->reltoastrelid;
+
+		toastrel = table_open(toastid, lockmode);
+
+		/* Fetch heap tuple */
+		tuple = SearchSysCache1(RELOID, ObjectIdGetDatum(toastid));
+		if (!HeapTupleIsValid(tuple))
+			elog(ERROR, "cache lookup failed for relation %u", toastid);
+
+		if (operation == AT_ReplaceRelOptions)
+		{
+			/*
+			 * If we're supposed to replace the reloptions list, we just
+			 * pretend there were none before.
+			 */
+			datum = (Datum) 0;
+			isnull = true;
+		}
+		else
+		{
+			/* Get the old reloptions */
+			datum = SysCacheGetAttr(RELOID, tuple, Anum_pg_class_reloptions,
+									&isnull);
+		}
+
+		newOptions = transformRelOptions(isnull ? (Datum) 0 : datum,
+										 defList, "toast", validnsps, false,
+										 operation == AT_ResetRelOptions);
+
+		(void) heap_reloptions(RELKIND_TOASTVALUE, newOptions, true);
+
+		memset(repl_val, 0, sizeof(repl_val));
+		memset(repl_null, false, sizeof(repl_null));
+		memset(repl_repl, false, sizeof(repl_repl));
+
+		if (newOptions != (Datum) 0)
+			repl_val[Anum_pg_class_reloptions - 1] = newOptions;
+		else
+			repl_null[Anum_pg_class_reloptions - 1] = true;
+
+		repl_repl[Anum_pg_class_reloptions - 1] = true;
+
+		newtuple = heap_modify_tuple(tuple, RelationGetDescr(pgclass),
+									 repl_val, repl_null, repl_repl);
+
+		CatalogTupleUpdate(pgclass, &newtuple->t_self, newtuple);
+
+		InvokeObjectPostAlterHookArg(RelationRelationId,
+									 RelationGetRelid(toastrel), 0,
+									 InvalidOid, true);
+
+		heap_freetuple(newtuple);
+
+		ReleaseSysCache(tuple);
+
+		table_close(toastrel, NoLock);
+	}
+
+	table_close(pgclass, RowExclusiveLock);
+}
+
+/*
+ * Execute ALTER TABLE SET TABLESPACE for cases where there is no tuple
+ * rewriting to be done, so we just want to copy the data as fast as possible.
+ */
+static void
+ATExecSetTableSpace(Oid tableOid, Oid newTableSpace, LOCKMODE lockmode)
+{
+	Relation	rel;
+	Oid			reltoastrelid;
+	Oid			newrelfilenode;
+	RelFileNode newrnode;
+	List	   *reltoastidxids = NIL;
+	ListCell   *lc;
+
+	/*
+	 * Need lock here in case we are recursing to toast table or index
+	 */
+	rel = relation_open(tableOid, lockmode);
+
+	/* Check first if relation can be moved to new tablespace */
+	if (!CheckRelationTableSpaceMove(rel, newTableSpace))
+	{
+		InvokeObjectPostAlterHook(RelationRelationId,
+								  RelationGetRelid(rel), 0);
+		relation_close(rel, NoLock);
+		return;
+	}
+
+	reltoastrelid = rel->rd_rel->reltoastrelid;
+	/* Fetch the list of indexes on toast relation if necessary */
+	if (OidIsValid(reltoastrelid))
+	{
+		Relation	toastRel = relation_open(reltoastrelid, lockmode);
+
+		reltoastidxids = RelationGetIndexList(toastRel);
+		relation_close(toastRel, lockmode);
+	}
+
+	/*
+	 * Relfilenodes are not unique in databases across tablespaces, so we need
+	 * to allocate a new one in the new tablespace.
+	 */
+	newrelfilenode = GetNewRelFileNode(newTableSpace, NULL,
+									   rel->rd_rel->relpersistence);
+
+	/* Open old and new relation */
+	newrnode = rel->rd_node;
+	newrnode.relNode = newrelfilenode;
+	newrnode.spcNode = newTableSpace;
+
+	/* hand off to AM to actually create the new filenode and copy the data */
+	if (rel->rd_rel->relkind == RELKIND_INDEX)
+	{
+		index_copy_data(rel, newrnode);
+	}
+	else
+	{
+		Assert(RELKIND_HAS_TABLE_AM(rel->rd_rel->relkind));
+		table_relation_copy_data(rel, &newrnode);
+	}
+
+	/*
+	 * Update the pg_class row.
+	 *
+	 * NB: This wouldn't work if ATExecSetTableSpace() were allowed to be
+	 * executed on pg_class or its indexes (the above copy wouldn't contain
+	 * the updated pg_class entry), but that's forbidden with
+	 * CheckRelationTableSpaceMove().
+	 */
+	SetRelationTableSpace(rel, newTableSpace, newrelfilenode);
+
+	InvokeObjectPostAlterHook(RelationRelationId, RelationGetRelid(rel), 0);
+
+	RelationAssumeNewRelfilenode(rel);
+
+	relation_close(rel, NoLock);
+
+	/* Make sure the reltablespace change is visible */
+	CommandCounterIncrement();
+
+	/* Move associated toast relation and/or indexes, too */
+	if (OidIsValid(reltoastrelid))
+		ATExecSetTableSpace(reltoastrelid, newTableSpace, lockmode);
+	foreach(lc, reltoastidxids)
+		ATExecSetTableSpace(lfirst_oid(lc), newTableSpace, lockmode);
+
+	/* Clean up */
+	list_free(reltoastidxids);
+}
+
+/*
+ * Special handling of ALTER TABLE SET TABLESPACE for relations with no
+ * storage that have an interest in preserving tablespace.
+ *
+ * Since these have no storage the tablespace can be updated with a simple
+ * metadata only operation to update the tablespace.
+ */
+static void
+ATExecSetTableSpaceNoStorage(Relation rel, Oid newTableSpace)
+{
+	/*
+	 * Shouldn't be called on relations having storage; these are processed in
+	 * phase 3.
+	 */
+	Assert(!RELKIND_HAS_STORAGE(rel->rd_rel->relkind));
+
+	/* check if relation can be moved to its new tablespace */
+	if (!CheckRelationTableSpaceMove(rel, newTableSpace))
+	{
+		InvokeObjectPostAlterHook(RelationRelationId,
+								  RelationGetRelid(rel),
+								  0);
+		return;
+	}
+
+	/* Update can be done, so change reltablespace */
+	SetRelationTableSpace(rel, newTableSpace, InvalidOid);
+
+	InvokeObjectPostAlterHook(RelationRelationId, RelationGetRelid(rel), 0);
+
+	/* Make sure the reltablespace change is visible */
+	CommandCounterIncrement();
+}
+
+/*
+ * Alter Table ALL ... SET TABLESPACE
+ *
+ * Allows a user to move all objects of some type in a given tablespace in the
+ * current database to another tablespace.  Objects can be chosen based on the
+ * owner of the object also, to allow users to move only their objects.
+ * The user must have CREATE rights on the new tablespace, as usual.   The main
+ * permissions handling is done by the lower-level table move function.
+ *
+ * All to-be-moved objects are locked first. If NOWAIT is specified and the
+ * lock can't be acquired then we ereport(ERROR).
+ */
+Oid
+AlterTableMoveAll(AlterTableMoveAllStmt *stmt)
+{
+	List	   *relations = NIL;
+	ListCell   *l;
+	ScanKeyData key[1];
+	Relation	rel;
+	TableScanDesc scan;
+	HeapTuple	tuple;
+	Oid			orig_tablespaceoid;
+	Oid			new_tablespaceoid;
+	List	   *role_oids = roleSpecsToIds(stmt->roles);
+
+	/* Ensure we were not asked to move something we can't */
+	if (stmt->objtype != OBJECT_TABLE && stmt->objtype != OBJECT_INDEX &&
+		stmt->objtype != OBJECT_MATVIEW)
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("only tables, indexes, and materialized views exist in tablespaces")));
+
+	/* Get the orig and new tablespace OIDs */
+	orig_tablespaceoid = get_tablespace_oid(stmt->orig_tablespacename, false);
+	new_tablespaceoid = get_tablespace_oid(stmt->new_tablespacename, false);
+
+	/* Can't move shared relations in to or out of pg_global */
+	/* This is also checked by ATExecSetTableSpace, but nice to stop earlier */
+	if (orig_tablespaceoid == GLOBALTABLESPACE_OID ||
+		new_tablespaceoid == GLOBALTABLESPACE_OID)
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("cannot move relations in to or out of pg_global tablespace")));
+
+	/*
+	 * Must have CREATE rights on the new tablespace, unless it is the
+	 * database default tablespace (which all users implicitly have CREATE
+	 * rights on).
+	 */
+	if (OidIsValid(new_tablespaceoid) && new_tablespaceoid != MyDatabaseTableSpace)
+	{
+		AclResult	aclresult;
+
+		aclresult = pg_tablespace_aclcheck(new_tablespaceoid, GetUserId(),
+										   ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(new_tablespaceoid));
+	}
+
+	/*
+	 * Now that the checks are done, check if we should set either to
+	 * InvalidOid because it is our database's default tablespace.
+	 */
+	if (orig_tablespaceoid == MyDatabaseTableSpace)
+		orig_tablespaceoid = InvalidOid;
+
+	if (new_tablespaceoid == MyDatabaseTableSpace)
+		new_tablespaceoid = InvalidOid;
+
+	/* no-op */
+	if (orig_tablespaceoid == new_tablespaceoid)
+		return new_tablespaceoid;
+
+	/*
+	 * Walk the list of objects in the tablespace and move them. This will
+	 * only find objects in our database, of course.
+	 */
+	ScanKeyInit(&key[0],
+				Anum_pg_class_reltablespace,
+				BTEqualStrategyNumber, F_OIDEQ,
+				ObjectIdGetDatum(orig_tablespaceoid));
+
+	rel = table_open(RelationRelationId, AccessShareLock);
+	scan = table_beginscan_catalog(rel, 1, key);
+	while ((tuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
+	{
+		Form_pg_class relForm = (Form_pg_class) GETSTRUCT(tuple);
+		Oid			relOid = relForm->oid;
+
+		/*
+		 * Do not move objects in pg_catalog as part of this, if an admin
+		 * really wishes to do so, they can issue the individual ALTER
+		 * commands directly.
+		 *
+		 * Also, explicitly avoid any shared tables, temp tables, or TOAST
+		 * (TOAST will be moved with the main table).
+		 */
+		if (IsCatalogNamespace(relForm->relnamespace) ||
+			relForm->relisshared ||
+			isAnyTempNamespace(relForm->relnamespace) ||
+			IsToastNamespace(relForm->relnamespace))
+			continue;
+
+		/* Only move the object type requested */
+		if ((stmt->objtype == OBJECT_TABLE &&
+			 relForm->relkind != RELKIND_RELATION &&
+			 relForm->relkind != RELKIND_PARTITIONED_TABLE) ||
+			(stmt->objtype == OBJECT_INDEX &&
+			 relForm->relkind != RELKIND_INDEX &&
+			 relForm->relkind != RELKIND_PARTITIONED_INDEX) ||
+			(stmt->objtype == OBJECT_MATVIEW &&
+			 relForm->relkind != RELKIND_MATVIEW))
+			continue;
+
+		/* Check if we are only moving objects owned by certain roles */
+		if (role_oids != NIL && !list_member_oid(role_oids, relForm->relowner))
+			continue;
+
+		/*
+		 * Handle permissions-checking here since we are locking the tables
+		 * and also to avoid doing a bunch of work only to fail part-way. Note
+		 * that permissions will also be checked by AlterTableInternal().
+		 *
+		 * Caller must be considered an owner on the table to move it.
+		 */
+		if (!pg_class_ownercheck(relOid, GetUserId()))
+			aclcheck_error(ACLCHECK_NOT_OWNER, get_relkind_objtype(get_rel_relkind(relOid)),
+						   NameStr(relForm->relname));
+
+		if (stmt->nowait &&
+			!ConditionalLockRelationOid(relOid, AccessExclusiveLock))
+			ereport(ERROR,
+					(errcode(ERRCODE_OBJECT_IN_USE),
+					 errmsg("aborting because lock on relation \"%s.%s\" is not available",
+							get_namespace_name(relForm->relnamespace),
+							NameStr(relForm->relname))));
+		else
+			LockRelationOid(relOid, AccessExclusiveLock);
+
+		/* Add to our list of objects to move */
+		relations = lappend_oid(relations, relOid);
+	}
+
+	table_endscan(scan);
+	table_close(rel, AccessShareLock);
+
+	if (relations == NIL)
+		ereport(NOTICE,
+				(errcode(ERRCODE_NO_DATA_FOUND),
+				 errmsg("no matching relations in tablespace \"%s\" found",
+						orig_tablespaceoid == InvalidOid ? "(database default)" :
+						get_tablespace_name(orig_tablespaceoid))));
+
+	/* Everything is locked, loop through and move all of the relations. */
+	foreach(l, relations)
+	{
+		List	   *cmds = NIL;
+		AlterTableCmd *cmd = makeNode(AlterTableCmd);
+
+		cmd->subtype = AT_SetTableSpace;
+		cmd->name = stmt->new_tablespacename;
+
+		cmds = lappend(cmds, cmd);
+
+		EventTriggerAlterTableStart((Node *) stmt);
+		/* OID is set by AlterTableInternal */
+		AlterTableInternal(lfirst_oid(l), cmds, false);
+		EventTriggerAlterTableEnd();
+	}
+
+	return new_tablespaceoid;
+}
+
+static void
+index_copy_data(Relation rel, RelFileNode newrnode)
+{
+	SMgrRelation dstrel;
+
+	dstrel = smgropen(newrnode, rel->rd_backend);
+
+	/*
+	 * Since we copy the file directly without looking at the shared buffers,
+	 * we'd better first flush out any pages of the source relation that are
+	 * in shared buffers.  We assume no new changes will be made while we are
+	 * holding exclusive lock on the rel.
+	 */
+	FlushRelationBuffers(rel);
+
+	/*
+	 * Create and copy all forks of the relation, and schedule unlinking of
+	 * old physical files.
+	 *
+	 * NOTE: any conflict in relfilenode value will be caught in
+	 * RelationCreateStorage().
+	 */
+	RelationCreateStorage(newrnode, rel->rd_rel->relpersistence, true);
+
+	/* copy main fork */
+	RelationCopyStorage(RelationGetSmgr(rel), dstrel, MAIN_FORKNUM,
+						rel->rd_rel->relpersistence);
+
+	/* copy those extra forks that exist */
+	for (ForkNumber forkNum = MAIN_FORKNUM + 1;
+		 forkNum <= MAX_FORKNUM; forkNum++)
+	{
+		if (smgrexists(RelationGetSmgr(rel), forkNum))
+		{
+			smgrcreate(dstrel, forkNum, false);
+
+			/*
+			 * WAL log creation if the relation is persistent, or this is the
+			 * init fork of an unlogged relation.
+			 */
+			if (RelationIsPermanent(rel) ||
+				(rel->rd_rel->relpersistence == RELPERSISTENCE_UNLOGGED &&
+				 forkNum == INIT_FORKNUM))
+				log_smgrcreate(&newrnode, forkNum);
+			RelationCopyStorage(RelationGetSmgr(rel), dstrel, forkNum,
+								rel->rd_rel->relpersistence);
+		}
+	}
+
+	/* drop old relation, and close new one */
+	RelationDropStorage(rel);
+	smgrclose(dstrel);
+}
+
+/*
+ * ALTER TABLE ENABLE/DISABLE TRIGGER
+ *
+ * We just pass this off to trigger.c.
+ */
+static void
+ATExecEnableDisableTrigger(Relation rel, const char *trigname,
+						   char fires_when, bool skip_system, bool recurse,
+						   LOCKMODE lockmode)
+{
+	EnableDisableTriggerNew2(rel, trigname, InvalidOid,
+							 fires_when, skip_system, recurse,
+							 lockmode);
+}
+
+/*
+ * ALTER TABLE ENABLE/DISABLE RULE
+ *
+ * We just pass this off to rewriteDefine.c.
+ */
+static void
+ATExecEnableDisableRule(Relation rel, const char *rulename,
+						char fires_when, LOCKMODE lockmode)
+{
+	EnableDisableRule(rel, rulename, fires_when);
+}
+
+/*
+ * ALTER TABLE INHERIT
+ *
+ * Add a parent to the child's parents. This verifies that all the columns and
+ * check constraints of the parent appear in the child and that they have the
+ * same data types and expressions.
+ */
+static void
+ATPrepAddInherit(Relation child_rel)
+{
+	if (child_rel->rd_rel->reloftype)
+		ereport(ERROR,
+				(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+				 errmsg("cannot change inheritance of typed table")));
+
+	if (child_rel->rd_rel->relispartition)
+		ereport(ERROR,
+				(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+				 errmsg("cannot change inheritance of a partition")));
+
+	if (child_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
+		ereport(ERROR,
+				(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+				 errmsg("cannot change inheritance of partitioned table")));
+}
+
+/*
+ * Return the address of the new parent relation.
+ */
+static ObjectAddress
+ATExecAddInherit(Relation child_rel, RangeVar *parent, LOCKMODE lockmode)
+{
+	Relation	parent_rel;
+	List	   *children;
+	ObjectAddress address;
+	const char *trigger_name;
+
+	/*
+	 * A self-exclusive lock is needed here.  See the similar case in
+	 * MergeAttributes() for a full explanation.
+	 */
+	parent_rel = table_openrv(parent, ShareUpdateExclusiveLock);
+
+	/*
+	 * Must be owner of both parent and child -- child was checked by
+	 * ATSimplePermissions call in ATPrepCmd
+	 */
+	ATSimplePermissions(AT_AddInherit, parent_rel, ATT_TABLE | ATT_FOREIGN_TABLE);
+
+	/* Permanent rels cannot inherit from temporary ones */
+	if (parent_rel->rd_rel->relpersistence == RELPERSISTENCE_TEMP &&
+		child_rel->rd_rel->relpersistence != RELPERSISTENCE_TEMP)
+		ereport(ERROR,
+				(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+				 errmsg("cannot inherit from temporary relation \"%s\"",
+						RelationGetRelationName(parent_rel))));
+
+	/* If parent rel is temp, it must belong to this session */
+	if (parent_rel->rd_rel->relpersistence == RELPERSISTENCE_TEMP &&
+		!parent_rel->rd_islocaltemp)
+		ereport(ERROR,
+				(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+				 errmsg("cannot inherit from temporary relation of another session")));
+
+	/* Ditto for the child */
+	if (child_rel->rd_rel->relpersistence == RELPERSISTENCE_TEMP &&
+		!child_rel->rd_islocaltemp)
+		ereport(ERROR,
+				(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+				 errmsg("cannot inherit to temporary relation of another session")));
+
+	/* Prevent partitioned tables from becoming inheritance parents */
+	if (parent_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
+		ereport(ERROR,
+				(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+				 errmsg("cannot inherit from partitioned table \"%s\"",
+						parent->relname)));
+
+	/* Likewise for partitions */
+	if (parent_rel->rd_rel->relispartition)
+		ereport(ERROR,
+				(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+				 errmsg("cannot inherit from a partition")));
+
+	/*
+	 * Prevent circularity by seeing if proposed parent inherits from child.
+	 * (In particular, this disallows making a rel inherit from itself.)
+	 *
+	 * This is not completely bulletproof because of race conditions: in
+	 * multi-level inheritance trees, someone else could concurrently be
+	 * making another inheritance link that closes the loop but does not join
+	 * either of the rels we have locked.  Preventing that seems to require
+	 * exclusive locks on the entire inheritance tree, which is a cure worse
+	 * than the disease.  find_all_inheritors() will cope with circularity
+	 * anyway, so don't sweat it too much.
+	 *
+	 * We use weakest lock we can on child's children, namely AccessShareLock.
+	 */
+	children = find_all_inheritors(RelationGetRelid(child_rel),
+								   AccessShareLock, NULL);
+
+	if (list_member_oid(children, RelationGetRelid(parent_rel)))
+		ereport(ERROR,
+				(errcode(ERRCODE_DUPLICATE_TABLE),
+				 errmsg("circular inheritance not allowed"),
+				 errdetail("\"%s\" is already a child of \"%s\".",
+						   parent->relname,
+						   RelationGetRelationName(child_rel))));
+
+	/*
+	 * If child_rel has row-level triggers with transition tables, we
+	 * currently don't allow it to become an inheritance child.  See also
+	 * prohibitions in ATExecAttachPartition() and CreateTrigger().
+	 */
+	trigger_name = FindTriggerIncompatibleWithInheritance(child_rel->trigdesc);
+	if (trigger_name != NULL)
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("trigger \"%s\" prevents table \"%s\" from becoming an inheritance child",
+						trigger_name, RelationGetRelationName(child_rel)),
+				 errdetail("ROW triggers with transition tables are not supported in inheritance hierarchies.")));
+
+	/* OK to create inheritance */
+	CreateInheritance(child_rel, parent_rel);
+
+	ObjectAddressSet(address, RelationRelationId,
+					 RelationGetRelid(parent_rel));
+
+	/* keep our lock on the parent relation until commit */
+	table_close(parent_rel, NoLock);
+
+	return address;
+}
+
+/*
+ * CreateInheritance
+ *		Catalog manipulation portion of creating inheritance between a child
+ *		table and a parent table.
+ *
+ * Common to ATExecAddInherit() and ATExecAttachPartition().
+ */
+static void
+CreateInheritance(Relation child_rel, Relation parent_rel)
+{
+	Relation	catalogRelation;
+	SysScanDesc scan;
+	ScanKeyData key;
+	HeapTuple	inheritsTuple;
+	int32		inhseqno;
+
+	/* Note: get RowExclusiveLock because we will write pg_inherits below. */
+	catalogRelation = table_open(InheritsRelationId, RowExclusiveLock);
+
+	/*
+	 * Check for duplicates in the list of parents, and determine the highest
+	 * inhseqno already present; we'll use the next one for the new parent.
+	 * Also, if proposed child is a partition, it cannot already be
+	 * inheriting.
+	 *
+	 * Note: we do not reject the case where the child already inherits from
+	 * the parent indirectly; CREATE TABLE doesn't reject comparable cases.
+	 */
+	ScanKeyInit(&key,
+				Anum_pg_inherits_inhrelid,
+				BTEqualStrategyNumber, F_OIDEQ,
+				ObjectIdGetDatum(RelationGetRelid(child_rel)));
+	scan = systable_beginscan(catalogRelation, InheritsRelidSeqnoIndexId,
+							  true, NULL, 1, &key);
+
+	/* inhseqno sequences start at 1 */
+	inhseqno = 0;
+	while (HeapTupleIsValid(inheritsTuple = systable_getnext(scan)))
+	{
+		Form_pg_inherits inh = (Form_pg_inherits) GETSTRUCT(inheritsTuple);
+
+		if (inh->inhparent == RelationGetRelid(parent_rel))
+			ereport(ERROR,
+					(errcode(ERRCODE_DUPLICATE_TABLE),
+					 errmsg("relation \"%s\" would be inherited from more than once",
+							RelationGetRelationName(parent_rel))));
+
+		if (inh->inhseqno > inhseqno)
+			inhseqno = inh->inhseqno;
+	}
+	systable_endscan(scan);
+
+	/* Match up the columns and bump attinhcount as needed */
+	MergeAttributesIntoExisting(child_rel, parent_rel);
+
+	/* Match up the constraints and bump coninhcount as needed */
+	MergeConstraintsIntoExisting(child_rel, parent_rel);
+
+	/*
+	 * OK, it looks valid.  Make the catalog entries that show inheritance.
+	 */
+	StoreCatalogInheritance1(RelationGetRelid(child_rel),
+							 RelationGetRelid(parent_rel),
+							 inhseqno + 1,
+							 catalogRelation,
+							 parent_rel->rd_rel->relkind ==
+							 RELKIND_PARTITIONED_TABLE);
+
+	/* Now we're done with pg_inherits */
+	table_close(catalogRelation, RowExclusiveLock);
+}
+
+/*
+ * Obtain the source-text form of the constraint expression for a check
+ * constraint, given its pg_constraint tuple
+ */
+static char *
+decompile_conbin(HeapTuple contup, TupleDesc tupdesc)
+{
+	Form_pg_constraint con;
+	bool		isnull;
+	Datum		attr;
+	Datum		expr;
+
+	con = (Form_pg_constraint) GETSTRUCT(contup);
+	attr = heap_getattr(contup, Anum_pg_constraint_conbin, tupdesc, &isnull);
+	if (isnull)
+		elog(ERROR, "null conbin for constraint %u", con->oid);
+
+	expr = DirectFunctionCall2(pg_get_expr, attr,
+							   ObjectIdGetDatum(con->conrelid));
+	return TextDatumGetCString(expr);
+}
+
+/*
+ * Determine whether two check constraints are functionally equivalent
+ *
+ * The test we apply is to see whether they reverse-compile to the same
+ * source string.  This insulates us from issues like whether attributes
+ * have the same physical column numbers in parent and child relations.
+ */
+static bool
+constraints_equivalent(HeapTuple a, HeapTuple b, TupleDesc tupleDesc)
+{
+	Form_pg_constraint acon = (Form_pg_constraint) GETSTRUCT(a);
+	Form_pg_constraint bcon = (Form_pg_constraint) GETSTRUCT(b);
+
+	if (acon->condeferrable != bcon->condeferrable ||
+		acon->condeferred != bcon->condeferred ||
+		strcmp(decompile_conbin(a, tupleDesc),
+			   decompile_conbin(b, tupleDesc)) != 0)
+		return false;
+	else
+		return true;
+}
+
+/*
+ * Check columns in child table match up with columns in parent, and increment
+ * their attinhcount.
+ *
+ * Called by CreateInheritance
+ *
+ * Currently all parent columns must be found in child. Missing columns are an
+ * error.  One day we might consider creating new columns like CREATE TABLE
+ * does.  However, that is widely unpopular --- in the common use case of
+ * partitioned tables it's a foot-gun.
+ *
+ * The data type must match exactly. If the parent column is NOT NULL then
+ * the child must be as well. Defaults are not compared, however.
+ */
+static void
+MergeAttributesIntoExisting(Relation child_rel, Relation parent_rel)
+{
+	Relation	attrrel;
+	AttrNumber	parent_attno;
+	int			parent_natts;
+	TupleDesc	tupleDesc;
+	HeapTuple	tuple;
+	bool		child_is_partition = false;
+
+	attrrel = table_open(AttributeRelationId, RowExclusiveLock);
+
+	tupleDesc = RelationGetDescr(parent_rel);
+	parent_natts = tupleDesc->natts;
+
+	/* If parent_rel is a partitioned table, child_rel must be a partition */
+	if (parent_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
+		child_is_partition = true;
+
+	for (parent_attno = 1; parent_attno <= parent_natts; parent_attno++)
+	{
+		Form_pg_attribute attribute = TupleDescAttr(tupleDesc,
+													parent_attno - 1);
+		char	   *attributeName = NameStr(attribute->attname);
+
+		/* Ignore dropped columns in the parent. */
+		if (attribute->attisdropped)
+			continue;
+
+		/* Find same column in child (matching on column name). */
+		tuple = SearchSysCacheCopyAttName(RelationGetRelid(child_rel),
+										  attributeName);
+		if (HeapTupleIsValid(tuple))
+		{
+			/* Check they are same type, typmod, and collation */
+			Form_pg_attribute childatt = (Form_pg_attribute) GETSTRUCT(tuple);
+
+			if (attribute->atttypid != childatt->atttypid ||
+				attribute->atttypmod != childatt->atttypmod)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("child table \"%s\" has different type for column \"%s\"",
+								RelationGetRelationName(child_rel),
+								attributeName)));
+
+			if (attribute->attcollation != childatt->attcollation)
+				ereport(ERROR,
+						(errcode(ERRCODE_COLLATION_MISMATCH),
+						 errmsg("child table \"%s\" has different collation for column \"%s\"",
+								RelationGetRelationName(child_rel),
+								attributeName)));
+
+			/*
+			 * Check child doesn't discard NOT NULL property.  (Other
+			 * constraints are checked elsewhere.)
+			 */
+			if (attribute->attnotnull && !childatt->attnotnull)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("column \"%s\" in child table must be marked NOT NULL",
+								attributeName)));
+
+			/*
+			 * If parent column is generated, child column must be, too.
+			 */
+			if (attribute->attgenerated && !childatt->attgenerated)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("column \"%s\" in child table must be a generated column",
+								attributeName)));
+
+			/*
+			 * Check that both generation expressions match.
+			 *
+			 * The test we apply is to see whether they reverse-compile to the
+			 * same source string.  This insulates us from issues like whether
+			 * attributes have the same physical column numbers in parent and
+			 * child relations.  (See also constraints_equivalent().)
+			 */
+			if (attribute->attgenerated && childatt->attgenerated)
+			{
+				TupleConstr *child_constr = child_rel->rd_att->constr;
+				TupleConstr *parent_constr = parent_rel->rd_att->constr;
+				char	   *child_expr = NULL;
+				char	   *parent_expr = NULL;
+
+				Assert(child_constr != NULL);
+				Assert(parent_constr != NULL);
+
+				for (int i = 0; i < child_constr->num_defval; i++)
+				{
+					if (child_constr->defval[i].adnum == childatt->attnum)
+					{
+						child_expr =
+							TextDatumGetCString(DirectFunctionCall2(pg_get_expr,
+																	CStringGetTextDatum(child_constr->defval[i].adbin),
+																	ObjectIdGetDatum(child_rel->rd_id)));
+						break;
+					}
+				}
+				Assert(child_expr != NULL);
+
+				for (int i = 0; i < parent_constr->num_defval; i++)
+				{
+					if (parent_constr->defval[i].adnum == attribute->attnum)
+					{
+						parent_expr =
+							TextDatumGetCString(DirectFunctionCall2(pg_get_expr,
+																	CStringGetTextDatum(parent_constr->defval[i].adbin),
+																	ObjectIdGetDatum(parent_rel->rd_id)));
+						break;
+					}
+				}
+				Assert(parent_expr != NULL);
+
+				if (strcmp(child_expr, parent_expr) != 0)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("column \"%s\" in child table has a conflicting generation expression",
+									attributeName)));
+			}
+
+			/*
+			 * OK, bump the child column's inheritance count.  (If we fail
+			 * later on, this change will just roll back.)
+			 */
+			childatt->attinhcount++;
+
+			/*
+			 * In case of partitions, we must enforce that value of attislocal
+			 * is same in all partitions. (Note: there are only inherited
+			 * attributes in partitions)
+			 */
+			if (child_is_partition)
+			{
+				Assert(childatt->attinhcount == 1);
+				childatt->attislocal = false;
+			}
+
+			CatalogTupleUpdate(attrrel, &tuple->t_self, tuple);
+			heap_freetuple(tuple);
+		}
+		else
+		{
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("child table is missing column \"%s\"",
+							attributeName)));
+		}
+	}
+
+	table_close(attrrel, RowExclusiveLock);
+}
+
+/*
+ * Check constraints in child table match up with constraints in parent,
+ * and increment their coninhcount.
+ *
+ * Constraints that are marked ONLY in the parent are ignored.
+ *
+ * Called by CreateInheritance
+ *
+ * Currently all constraints in parent must be present in the child. One day we
+ * may consider adding new constraints like CREATE TABLE does.
+ *
+ * XXX This is O(N^2) which may be an issue with tables with hundreds of
+ * constraints. As long as tables have more like 10 constraints it shouldn't be
+ * a problem though. Even 100 constraints ought not be the end of the world.
+ *
+ * XXX See MergeWithExistingConstraint too if you change this code.
+ */
+static void
+MergeConstraintsIntoExisting(Relation child_rel, Relation parent_rel)
+{
+	Relation	catalog_relation;
+	TupleDesc	tuple_desc;
+	SysScanDesc parent_scan;
+	ScanKeyData parent_key;
+	HeapTuple	parent_tuple;
+	bool		child_is_partition = false;
+
+	catalog_relation = table_open(ConstraintRelationId, RowExclusiveLock);
+	tuple_desc = RelationGetDescr(catalog_relation);
+
+	/* If parent_rel is a partitioned table, child_rel must be a partition */
+	if (parent_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
+		child_is_partition = true;
+
+	/* Outer loop scans through the parent's constraint definitions */
+	ScanKeyInit(&parent_key,
+				Anum_pg_constraint_conrelid,
+				BTEqualStrategyNumber, F_OIDEQ,
+				ObjectIdGetDatum(RelationGetRelid(parent_rel)));
+	parent_scan = systable_beginscan(catalog_relation, ConstraintRelidTypidNameIndexId,
+									 true, NULL, 1, &parent_key);
+
+	while (HeapTupleIsValid(parent_tuple = systable_getnext(parent_scan)))
+	{
+		Form_pg_constraint parent_con = (Form_pg_constraint) GETSTRUCT(parent_tuple);
+		SysScanDesc child_scan;
+		ScanKeyData child_key;
+		HeapTuple	child_tuple;
+		bool		found = false;
+
+		if (parent_con->contype != CONSTRAINT_CHECK)
+			continue;
+
+		/* if the parent's constraint is marked NO INHERIT, it's not inherited */
+		if (parent_con->connoinherit)
+			continue;
+
+		/* Search for a child constraint matching this one */
+		ScanKeyInit(&child_key,
+					Anum_pg_constraint_conrelid,
+					BTEqualStrategyNumber, F_OIDEQ,
+					ObjectIdGetDatum(RelationGetRelid(child_rel)));
+		child_scan = systable_beginscan(catalog_relation, ConstraintRelidTypidNameIndexId,
+										true, NULL, 1, &child_key);
+
+		while (HeapTupleIsValid(child_tuple = systable_getnext(child_scan)))
+		{
+			Form_pg_constraint child_con = (Form_pg_constraint) GETSTRUCT(child_tuple);
+			HeapTuple	child_copy;
+
+			if (child_con->contype != CONSTRAINT_CHECK)
+				continue;
+
+			if (strcmp(NameStr(parent_con->conname),
+					   NameStr(child_con->conname)) != 0)
+				continue;
+
+			if (!constraints_equivalent(parent_tuple, child_tuple, tuple_desc))
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("child table \"%s\" has different definition for check constraint \"%s\"",
+								RelationGetRelationName(child_rel),
+								NameStr(parent_con->conname))));
+
+			/* If the child constraint is "no inherit" then cannot merge */
+			if (child_con->connoinherit)
+				ereport(ERROR,
+						(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
+						 errmsg("constraint \"%s\" conflicts with non-inherited constraint on child table \"%s\"",
+								NameStr(child_con->conname),
+								RelationGetRelationName(child_rel))));
+
+			/*
+			 * If the child constraint is "not valid" then cannot merge with a
+			 * valid parent constraint
+			 */
+			if (parent_con->convalidated && !child_con->convalidated)
+				ereport(ERROR,
+						(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
+						 errmsg("constraint \"%s\" conflicts with NOT VALID constraint on child table \"%s\"",
+								NameStr(child_con->conname),
+								RelationGetRelationName(child_rel))));
+
+			/*
+			 * OK, bump the child constraint's inheritance count.  (If we fail
+			 * later on, this change will just roll back.)
+			 */
+			child_copy = heap_copytuple(child_tuple);
+			child_con = (Form_pg_constraint) GETSTRUCT(child_copy);
+			child_con->coninhcount++;
+
+			/*
+			 * In case of partitions, an inherited constraint must be
+			 * inherited only once since it cannot have multiple parents and
+			 * it is never considered local.
+			 */
+			if (child_is_partition)
+			{
+				Assert(child_con->coninhcount == 1);
+				child_con->conislocal = false;
+			}
+
+			CatalogTupleUpdate(catalog_relation, &child_copy->t_self, child_copy);
+			heap_freetuple(child_copy);
+
+			found = true;
+			break;
+		}
+
+		systable_endscan(child_scan);
+
+		if (!found)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("child table is missing constraint \"%s\"",
+							NameStr(parent_con->conname))));
+	}
+
+	systable_endscan(parent_scan);
+	table_close(catalog_relation, RowExclusiveLock);
+}
+
+/*
+ * ALTER TABLE NO INHERIT
+ *
+ * Return value is the address of the relation that is no longer parent.
+ */
+static ObjectAddress
+ATExecDropInherit(Relation rel, RangeVar *parent, LOCKMODE lockmode)
+{
+	ObjectAddress address;
+	Relation	parent_rel;
+
+	if (rel->rd_rel->relispartition)
+		ereport(ERROR,
+				(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+				 errmsg("cannot change inheritance of a partition")));
+
+	/*
+	 * AccessShareLock on the parent is probably enough, seeing that DROP
+	 * TABLE doesn't lock parent tables at all.  We need some lock since we'll
+	 * be inspecting the parent's schema.
+	 */
+	parent_rel = table_openrv(parent, AccessShareLock);
+
+	/*
+	 * We don't bother to check ownership of the parent table --- ownership of
+	 * the child is presumed enough rights.
+	 */
+
+	/* Off to RemoveInheritance() where most of the work happens */
+	RemoveInheritance(rel, parent_rel, false);
+
+	ObjectAddressSet(address, RelationRelationId,
+					 RelationGetRelid(parent_rel));
+
+	/* keep our lock on the parent relation until commit */
+	table_close(parent_rel, NoLock);
+
+	return address;
+}
+
+/*
+ * MarkInheritDetached
+ *
+ * Set inhdetachpending for a partition, for ATExecDetachPartition
+ * in concurrent mode.  While at it, verify that no other partition is
+ * already pending detach.
+ */
+static void
+MarkInheritDetached(Relation child_rel, Relation parent_rel)
+{
+	Relation	catalogRelation;
+	SysScanDesc scan;
+	ScanKeyData key;
+	HeapTuple	inheritsTuple;
+	bool		found = false;
+
+	Assert(parent_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE);
+
+	/*
+	 * Find pg_inherits entries by inhparent.  (We need to scan them all in
+	 * order to verify that no other partition is pending detach.)
+	 */
+	catalogRelation = table_open(InheritsRelationId, RowExclusiveLock);
+	ScanKeyInit(&key,
+				Anum_pg_inherits_inhparent,
+				BTEqualStrategyNumber, F_OIDEQ,
+				ObjectIdGetDatum(RelationGetRelid(parent_rel)));
+	scan = systable_beginscan(catalogRelation, InheritsParentIndexId,
+							  true, NULL, 1, &key);
+
+	while (HeapTupleIsValid(inheritsTuple = systable_getnext(scan)))
+	{
+		Form_pg_inherits inhForm;
+
+		inhForm = (Form_pg_inherits) GETSTRUCT(inheritsTuple);
+		if (inhForm->inhdetachpending)
+			ereport(ERROR,
+					errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+					errmsg("partition \"%s\" already pending detach in partitioned table \"%s.%s\"",
+						   get_rel_name(inhForm->inhrelid),
+						   get_namespace_name(parent_rel->rd_rel->relnamespace),
+						   RelationGetRelationName(parent_rel)),
+					errhint("Use ALTER TABLE ... DETACH PARTITION ... FINALIZE to complete the pending detach operation."));
+
+		if (inhForm->inhrelid == RelationGetRelid(child_rel))
+		{
+			HeapTuple	newtup;
+
+			newtup = heap_copytuple(inheritsTuple);
+			((Form_pg_inherits) GETSTRUCT(newtup))->inhdetachpending = true;
+
+			CatalogTupleUpdate(catalogRelation,
+							   &inheritsTuple->t_self,
+							   newtup);
+			found = true;
+			heap_freetuple(newtup);
+			/* keep looking, to ensure we catch others pending detach */
+		}
+	}
+
+	/* Done */
+	systable_endscan(scan);
+	table_close(catalogRelation, RowExclusiveLock);
+
+	if (!found)
+		ereport(ERROR,
+				(errcode(ERRCODE_UNDEFINED_TABLE),
+				 errmsg("relation \"%s\" is not a partition of relation \"%s\"",
+						RelationGetRelationName(child_rel),
+						RelationGetRelationName(parent_rel))));
+}
+
+/*
+ * RemoveInheritance
+ *
+ * Drop a parent from the child's parents. This just adjusts the attinhcount
+ * and attislocal of the columns and removes the pg_inherit and pg_depend
+ * entries.  expect_detached is passed down to DeleteInheritsTuple, q.v..
+ *
+ * If attinhcount goes to 0 then attislocal gets set to true. If it goes back
+ * up attislocal stays true, which means if a child is ever removed from a
+ * parent then its columns will never be automatically dropped which may
+ * surprise. But at least we'll never surprise by dropping columns someone
+ * isn't expecting to be dropped which would actually mean data loss.
+ *
+ * coninhcount and conislocal for inherited constraints are adjusted in
+ * exactly the same way.
+ *
+ * Common to ATExecDropInherit() and ATExecDetachPartition().
+ */
+static void
+RemoveInheritance(Relation child_rel, Relation parent_rel, bool expect_detached)
+{
+	Relation	catalogRelation;
+	SysScanDesc scan;
+	ScanKeyData key[3];
+	HeapTuple	attributeTuple,
+				constraintTuple;
+	List	   *connames;
+	bool		found;
+	bool		child_is_partition = false;
+
+	/* If parent_rel is a partitioned table, child_rel must be a partition */
+	if (parent_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
+		child_is_partition = true;
+
+	found = DeleteInheritsTuple(RelationGetRelid(child_rel),
+								RelationGetRelid(parent_rel),
+								expect_detached,
+								RelationGetRelationName(child_rel));
+	if (!found)
+	{
+		if (child_is_partition)
+			ereport(ERROR,
+					(errcode(ERRCODE_UNDEFINED_TABLE),
+					 errmsg("relation \"%s\" is not a partition of relation \"%s\"",
+							RelationGetRelationName(child_rel),
+							RelationGetRelationName(parent_rel))));
+		else
+			ereport(ERROR,
+					(errcode(ERRCODE_UNDEFINED_TABLE),
+					 errmsg("relation \"%s\" is not a parent of relation \"%s\"",
+							RelationGetRelationName(parent_rel),
+							RelationGetRelationName(child_rel))));
+	}
+
+	/*
+	 * Search through child columns looking for ones matching parent rel
+	 */
+	catalogRelation = table_open(AttributeRelationId, RowExclusiveLock);
+	ScanKeyInit(&key[0],
+				Anum_pg_attribute_attrelid,
+				BTEqualStrategyNumber, F_OIDEQ,
+				ObjectIdGetDatum(RelationGetRelid(child_rel)));
+	scan = systable_beginscan(catalogRelation, AttributeRelidNumIndexId,
+							  true, NULL, 1, key);
+	while (HeapTupleIsValid(attributeTuple = systable_getnext(scan)))
+	{
+		Form_pg_attribute att = (Form_pg_attribute) GETSTRUCT(attributeTuple);
+
+		/* Ignore if dropped or not inherited */
+		if (att->attisdropped)
+			continue;
+		if (att->attinhcount <= 0)
+			continue;
+
+		if (SearchSysCacheExistsAttName(RelationGetRelid(parent_rel),
+										NameStr(att->attname)))
+		{
+			/* Decrement inhcount and possibly set islocal to true */
+			HeapTuple	copyTuple = heap_copytuple(attributeTuple);
+			Form_pg_attribute copy_att = (Form_pg_attribute) GETSTRUCT(copyTuple);
+
+			copy_att->attinhcount--;
+			if (copy_att->attinhcount == 0)
+				copy_att->attislocal = true;
+
+			CatalogTupleUpdate(catalogRelation, &copyTuple->t_self, copyTuple);
+			heap_freetuple(copyTuple);
+		}
+	}
+	systable_endscan(scan);
+	table_close(catalogRelation, RowExclusiveLock);
+
+	/*
+	 * Likewise, find inherited check constraints and disinherit them. To do
+	 * this, we first need a list of the names of the parent's check
+	 * constraints.  (We cheat a bit by only checking for name matches,
+	 * assuming that the expressions will match.)
+	 */
+	catalogRelation = table_open(ConstraintRelationId, RowExclusiveLock);
+	ScanKeyInit(&key[0],
+				Anum_pg_constraint_conrelid,
+				BTEqualStrategyNumber, F_OIDEQ,
+				ObjectIdGetDatum(RelationGetRelid(parent_rel)));
+	scan = systable_beginscan(catalogRelation, ConstraintRelidTypidNameIndexId,
+							  true, NULL, 1, key);
+
+	connames = NIL;
+
+	while (HeapTupleIsValid(constraintTuple = systable_getnext(scan)))
+	{
+		Form_pg_constraint con = (Form_pg_constraint) GETSTRUCT(constraintTuple);
+
+		if (con->contype == CONSTRAINT_CHECK)
+			connames = lappend(connames, pstrdup(NameStr(con->conname)));
+	}
+
+	systable_endscan(scan);
+
+	/* Now scan the child's constraints */
+	ScanKeyInit(&key[0],
+				Anum_pg_constraint_conrelid,
+				BTEqualStrategyNumber, F_OIDEQ,
+				ObjectIdGetDatum(RelationGetRelid(child_rel)));
+	scan = systable_beginscan(catalogRelation, ConstraintRelidTypidNameIndexId,
+							  true, NULL, 1, key);
+
+	while (HeapTupleIsValid(constraintTuple = systable_getnext(scan)))
+	{
+		Form_pg_constraint con = (Form_pg_constraint) GETSTRUCT(constraintTuple);
+		bool		match;
+		ListCell   *lc;
+
+		if (con->contype != CONSTRAINT_CHECK)
+			continue;
+
+		match = false;
+		foreach(lc, connames)
+		{
+			if (strcmp(NameStr(con->conname), (char *) lfirst(lc)) == 0)
+			{
+				match = true;
+				break;
+			}
+		}
+
+		if (match)
+		{
+			/* Decrement inhcount and possibly set islocal to true */
+			HeapTuple	copyTuple = heap_copytuple(constraintTuple);
+			Form_pg_constraint copy_con = (Form_pg_constraint) GETSTRUCT(copyTuple);
+
+			if (copy_con->coninhcount <= 0) /* shouldn't happen */
+				elog(ERROR, "relation %u has non-inherited constraint \"%s\"",
+					 RelationGetRelid(child_rel), NameStr(copy_con->conname));
+
+			copy_con->coninhcount--;
+			if (copy_con->coninhcount == 0)
+				copy_con->conislocal = true;
+
+			CatalogTupleUpdate(catalogRelation, &copyTuple->t_self, copyTuple);
+			heap_freetuple(copyTuple);
+		}
+	}
+
+	systable_endscan(scan);
+	table_close(catalogRelation, RowExclusiveLock);
+
+	drop_parent_dependency(RelationGetRelid(child_rel),
+						   RelationRelationId,
+						   RelationGetRelid(parent_rel),
+						   child_dependency_type(child_is_partition));
+
+	/*
+	 * Post alter hook of this inherits. Since object_access_hook doesn't take
+	 * multiple object identifiers, we relay oid of parent relation using
+	 * auxiliary_id argument.
+	 */
+	InvokeObjectPostAlterHookArg(InheritsRelationId,
+								 RelationGetRelid(child_rel), 0,
+								 RelationGetRelid(parent_rel), false);
+}
+
+/*
+ * Drop the dependency created by StoreCatalogInheritance1 (CREATE TABLE
+ * INHERITS/ALTER TABLE INHERIT -- refclassid will be RelationRelationId) or
+ * heap_create_with_catalog (CREATE TABLE OF/ALTER TABLE OF -- refclassid will
+ * be TypeRelationId).  There's no convenient way to do this, so go trawling
+ * through pg_depend.
+ */
+static void
+drop_parent_dependency(Oid relid, Oid refclassid, Oid refobjid,
+					   DependencyType deptype)
+{
+	Relation	catalogRelation;
+	SysScanDesc scan;
+	ScanKeyData key[3];
+	HeapTuple	depTuple;
+
+	catalogRelation = table_open(DependRelationId, RowExclusiveLock);
+
+	ScanKeyInit(&key[0],
+				Anum_pg_depend_classid,
+				BTEqualStrategyNumber, F_OIDEQ,
+				ObjectIdGetDatum(RelationRelationId));
+	ScanKeyInit(&key[1],
+				Anum_pg_depend_objid,
+				BTEqualStrategyNumber, F_OIDEQ,
+				ObjectIdGetDatum(relid));
+	ScanKeyInit(&key[2],
+				Anum_pg_depend_objsubid,
+				BTEqualStrategyNumber, F_INT4EQ,
+				Int32GetDatum(0));
+
+	scan = systable_beginscan(catalogRelation, DependDependerIndexId, true,
+							  NULL, 3, key);
+
+	while (HeapTupleIsValid(depTuple = systable_getnext(scan)))
+	{
+		Form_pg_depend dep = (Form_pg_depend) GETSTRUCT(depTuple);
+
+		if (dep->refclassid == refclassid &&
+			dep->refobjid == refobjid &&
+			dep->refobjsubid == 0 &&
+			dep->deptype == deptype)
+			CatalogTupleDelete(catalogRelation, &depTuple->t_self);
+	}
+
+	systable_endscan(scan);
+	table_close(catalogRelation, RowExclusiveLock);
+}
+
+/*
+ * ALTER TABLE OF
+ *
+ * Attach a table to a composite type, as though it had been created with CREATE
+ * TABLE OF.  All attname, atttypid, atttypmod and attcollation must match.  The
+ * subject table must not have inheritance parents.  These restrictions ensure
+ * that you cannot create a configuration impossible with CREATE TABLE OF alone.
+ *
+ * The address of the type is returned.
+ */
+static ObjectAddress
+ATExecAddOf(Relation rel, const TypeName *ofTypename, LOCKMODE lockmode)
+{
+	Oid			relid = RelationGetRelid(rel);
+	Type		typetuple;
+	Form_pg_type typeform;
+	Oid			typeid;
+	Relation	inheritsRelation,
+				relationRelation;
+	SysScanDesc scan;
+	ScanKeyData key;
+	AttrNumber	table_attno,
+				type_attno;
+	TupleDesc	typeTupleDesc,
+				tableTupleDesc;
+	ObjectAddress tableobj,
+				typeobj;
+	HeapTuple	classtuple;
+
+	/* Validate the type. */
+	typetuple = typenameType(NULL, ofTypename, NULL);
+	check_of_type(typetuple);
+	typeform = (Form_pg_type) GETSTRUCT(typetuple);
+	typeid = typeform->oid;
+
+	/* Fail if the table has any inheritance parents. */
+	inheritsRelation = table_open(InheritsRelationId, AccessShareLock);
+	ScanKeyInit(&key,
+				Anum_pg_inherits_inhrelid,
+				BTEqualStrategyNumber, F_OIDEQ,
+				ObjectIdGetDatum(relid));
+	scan = systable_beginscan(inheritsRelation, InheritsRelidSeqnoIndexId,
+							  true, NULL, 1, &key);
+	if (HeapTupleIsValid(systable_getnext(scan)))
+		ereport(ERROR,
+				(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+				 errmsg("typed tables cannot inherit")));
+	systable_endscan(scan);
+	table_close(inheritsRelation, AccessShareLock);
+
+	/*
+	 * Check the tuple descriptors for compatibility.  Unlike inheritance, we
+	 * require that the order also match.  However, attnotnull need not match.
+	 */
+	typeTupleDesc = lookup_rowtype_tupdesc(typeid, -1);
+	tableTupleDesc = RelationGetDescr(rel);
+	table_attno = 1;
+	for (type_attno = 1; type_attno <= typeTupleDesc->natts; type_attno++)
+	{
+		Form_pg_attribute type_attr,
+					table_attr;
+		const char *type_attname,
+				   *table_attname;
+
+		/* Get the next non-dropped type attribute. */
+		type_attr = TupleDescAttr(typeTupleDesc, type_attno - 1);
+		if (type_attr->attisdropped)
+			continue;
+		type_attname = NameStr(type_attr->attname);
+
+		/* Get the next non-dropped table attribute. */
+		do
+		{
+			if (table_attno > tableTupleDesc->natts)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("table is missing column \"%s\"",
+								type_attname)));
+			table_attr = TupleDescAttr(tableTupleDesc, table_attno - 1);
+			table_attno++;
+		} while (table_attr->attisdropped);
+		table_attname = NameStr(table_attr->attname);
+
+		/* Compare name. */
+		if (strncmp(table_attname, type_attname, NAMEDATALEN) != 0)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("table has column \"%s\" where type requires \"%s\"",
+							table_attname, type_attname)));
+
+		/* Compare type. */
+		if (table_attr->atttypid != type_attr->atttypid ||
+			table_attr->atttypmod != type_attr->atttypmod ||
+			table_attr->attcollation != type_attr->attcollation)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("table \"%s\" has different type for column \"%s\"",
+							RelationGetRelationName(rel), type_attname)));
+	}
+	ReleaseTupleDesc(typeTupleDesc);
+
+	/* Any remaining columns at the end of the table had better be dropped. */
+	for (; table_attno <= tableTupleDesc->natts; table_attno++)
+	{
+		Form_pg_attribute table_attr = TupleDescAttr(tableTupleDesc,
+													 table_attno - 1);
+
+		if (!table_attr->attisdropped)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("table has extra column \"%s\"",
+							NameStr(table_attr->attname))));
+	}
+
+	/* If the table was already typed, drop the existing dependency. */
+	if (rel->rd_rel->reloftype)
+		drop_parent_dependency(relid, TypeRelationId, rel->rd_rel->reloftype,
+							   DEPENDENCY_NORMAL);
+
+	/* Record a dependency on the new type. */
+	tableobj.classId = RelationRelationId;
+	tableobj.objectId = relid;
+	tableobj.objectSubId = 0;
+	typeobj.classId = TypeRelationId;
+	typeobj.objectId = typeid;
+	typeobj.objectSubId = 0;
+	recordDependencyOn(&tableobj, &typeobj, DEPENDENCY_NORMAL);
+
+	/* Update pg_class.reloftype */
+	relationRelation = table_open(RelationRelationId, RowExclusiveLock);
+	classtuple = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(relid));
+	if (!HeapTupleIsValid(classtuple))
+		elog(ERROR, "cache lookup failed for relation %u", relid);
+	((Form_pg_class) GETSTRUCT(classtuple))->reloftype = typeid;
+	CatalogTupleUpdate(relationRelation, &classtuple->t_self, classtuple);
+
+	InvokeObjectPostAlterHook(RelationRelationId, relid, 0);
+
+	heap_freetuple(classtuple);
+	table_close(relationRelation, RowExclusiveLock);
+
+	ReleaseSysCache(typetuple);
+
+	return typeobj;
+}
+
+/*
+ * ALTER TABLE NOT OF
+ *
+ * Detach a typed table from its originating type.  Just clear reloftype and
+ * remove the dependency.
+ */
+static void
+ATExecDropOf(Relation rel, LOCKMODE lockmode)
+{
+	Oid			relid = RelationGetRelid(rel);
+	Relation	relationRelation;
+	HeapTuple	tuple;
+
+	if (!OidIsValid(rel->rd_rel->reloftype))
+		ereport(ERROR,
+				(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+				 errmsg("\"%s\" is not a typed table",
+						RelationGetRelationName(rel))));
+
+	/*
+	 * We don't bother to check ownership of the type --- ownership of the
+	 * table is presumed enough rights.  No lock required on the type, either.
+	 */
+
+	drop_parent_dependency(relid, TypeRelationId, rel->rd_rel->reloftype,
+						   DEPENDENCY_NORMAL);
+
+	/* Clear pg_class.reloftype */
+	relationRelation = table_open(RelationRelationId, RowExclusiveLock);
+	tuple = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(relid));
+	if (!HeapTupleIsValid(tuple))
+		elog(ERROR, "cache lookup failed for relation %u", relid);
+	((Form_pg_class) GETSTRUCT(tuple))->reloftype = InvalidOid;
+	CatalogTupleUpdate(relationRelation, &tuple->t_self, tuple);
+
+	InvokeObjectPostAlterHook(RelationRelationId, relid, 0);
+
+	heap_freetuple(tuple);
+	table_close(relationRelation, RowExclusiveLock);
+}
+
+/*
+ * relation_mark_replica_identity: Update a table's replica identity
+ *
+ * Iff ri_type = REPLICA_IDENTITY_INDEX, indexOid must be the Oid of a suitable
+ * index. Otherwise, it must be InvalidOid.
+ *
+ * Caller had better hold an exclusive lock on the relation, as the results
+ * of running two of these concurrently wouldn't be pretty.
+ */
+static void
+relation_mark_replica_identity(Relation rel, char ri_type, Oid indexOid,
+							   bool is_internal)
+{
+	Relation	pg_index;
+	Relation	pg_class;
+	HeapTuple	pg_class_tuple;
+	HeapTuple	pg_index_tuple;
+	Form_pg_class pg_class_form;
+	Form_pg_index pg_index_form;
+	ListCell   *index;
+
+	/*
+	 * Check whether relreplident has changed, and update it if so.
+	 */
+	pg_class = table_open(RelationRelationId, RowExclusiveLock);
+	pg_class_tuple = SearchSysCacheCopy1(RELOID,
+										 ObjectIdGetDatum(RelationGetRelid(rel)));
+	if (!HeapTupleIsValid(pg_class_tuple))
+		elog(ERROR, "cache lookup failed for relation \"%s\"",
+			 RelationGetRelationName(rel));
+	pg_class_form = (Form_pg_class) GETSTRUCT(pg_class_tuple);
+	if (pg_class_form->relreplident != ri_type)
+	{
+		pg_class_form->relreplident = ri_type;
+		CatalogTupleUpdate(pg_class, &pg_class_tuple->t_self, pg_class_tuple);
+	}
+	table_close(pg_class, RowExclusiveLock);
+	heap_freetuple(pg_class_tuple);
+
+	/*
+	 * Update the per-index indisreplident flags correctly.
+	 */
+	pg_index = table_open(IndexRelationId, RowExclusiveLock);
+	foreach(index, RelationGetIndexList(rel))
+	{
+		Oid			thisIndexOid = lfirst_oid(index);
+		bool		dirty = false;
+
+		pg_index_tuple = SearchSysCacheCopy1(INDEXRELID,
+											 ObjectIdGetDatum(thisIndexOid));
+		if (!HeapTupleIsValid(pg_index_tuple))
+			elog(ERROR, "cache lookup failed for index %u", thisIndexOid);
+		pg_index_form = (Form_pg_index) GETSTRUCT(pg_index_tuple);
+
+		if (thisIndexOid == indexOid)
+		{
+			/* Set the bit if not already set. */
+			if (!pg_index_form->indisreplident)
+			{
+				dirty = true;
+				pg_index_form->indisreplident = true;
+			}
+		}
+		else
+		{
+			/* Unset the bit if set. */
+			if (pg_index_form->indisreplident)
+			{
+				dirty = true;
+				pg_index_form->indisreplident = false;
+			}
+		}
+
+		if (dirty)
+		{
+			CatalogTupleUpdate(pg_index, &pg_index_tuple->t_self, pg_index_tuple);
+			InvokeObjectPostAlterHookArg(IndexRelationId, thisIndexOid, 0,
+										 InvalidOid, is_internal);
+
+			/*
+			 * Invalidate the relcache for the table, so that after we commit
+			 * all sessions will refresh the table's replica identity index
+			 * before attempting any UPDATE or DELETE on the table.  (If we
+			 * changed the table's pg_class row above, then a relcache inval
+			 * is already queued due to that; but we might not have.)
+			 */
+			CacheInvalidateRelcache(rel);
+		}
+		heap_freetuple(pg_index_tuple);
+	}
+
+	table_close(pg_index, RowExclusiveLock);
+}
+
+/*
+ * ALTER TABLE <name> REPLICA IDENTITY ...
+ */
+static void
+ATExecReplicaIdentity(Relation rel, ReplicaIdentityStmt *stmt, LOCKMODE lockmode)
+{
+	Oid			indexOid;
+	Relation	indexRel;
+	int			key;
+
+	if (stmt->identity_type == REPLICA_IDENTITY_DEFAULT)
+	{
+		relation_mark_replica_identity(rel, stmt->identity_type, InvalidOid, true);
+		return;
+	}
+	else if (stmt->identity_type == REPLICA_IDENTITY_FULL)
+	{
+		relation_mark_replica_identity(rel, stmt->identity_type, InvalidOid, true);
+		return;
+	}
+	else if (stmt->identity_type == REPLICA_IDENTITY_NOTHING)
+	{
+		relation_mark_replica_identity(rel, stmt->identity_type, InvalidOid, true);
+		return;
+	}
+	else if (stmt->identity_type == REPLICA_IDENTITY_INDEX)
+	{
+		 /* fallthrough */ ;
+	}
+	else
+		elog(ERROR, "unexpected identity type %u", stmt->identity_type);
+
+	/* Check that the index exists */
+	indexOid = get_relname_relid(stmt->name, rel->rd_rel->relnamespace);
+	if (!OidIsValid(indexOid))
+		ereport(ERROR,
+				(errcode(ERRCODE_UNDEFINED_OBJECT),
+				 errmsg("index \"%s\" for table \"%s\" does not exist",
+						stmt->name, RelationGetRelationName(rel))));
+
+	indexRel = index_open(indexOid, ShareLock);
+
+	/* Check that the index is on the relation we're altering. */
+	if (indexRel->rd_index == NULL ||
+		indexRel->rd_index->indrelid != RelationGetRelid(rel))
+		ereport(ERROR,
+				(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+				 errmsg("\"%s\" is not an index for table \"%s\"",
+						RelationGetRelationName(indexRel),
+						RelationGetRelationName(rel))));
+	/* The AM must support uniqueness, and the index must in fact be unique. */
+	if (!indexRel->rd_indam->amcanunique ||
+		!indexRel->rd_index->indisunique)
+		ereport(ERROR,
+				(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+				 errmsg("cannot use non-unique index \"%s\" as replica identity",
+						RelationGetRelationName(indexRel))));
+	/* Deferred indexes are not guaranteed to be always unique. */
+	if (!indexRel->rd_index->indimmediate)
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("cannot use non-immediate index \"%s\" as replica identity",
+						RelationGetRelationName(indexRel))));
+	/* Expression indexes aren't supported. */
+	if (RelationGetIndexExpressions(indexRel) != NIL)
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("cannot use expression index \"%s\" as replica identity",
+						RelationGetRelationName(indexRel))));
+	/* Predicate indexes aren't supported. */
+	if (RelationGetIndexPredicate(indexRel) != NIL)
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("cannot use partial index \"%s\" as replica identity",
+						RelationGetRelationName(indexRel))));
+
+	/* Check index for nullable columns. */
+	for (key = 0; key < IndexRelationGetNumberOfKeyAttributes(indexRel); key++)
+	{
+		int16		attno = indexRel->rd_index->indkey.values[key];
+		Form_pg_attribute attr;
+
+		/*
+		 * Reject any other system columns.  (Going forward, we'll disallow
+		 * indexes containing such columns in the first place, but they might
+		 * exist in older branches.)
+		 */
+		if (attno <= 0)
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_COLUMN_REFERENCE),
+					 errmsg("index \"%s\" cannot be used as replica identity because column %d is a system column",
+							RelationGetRelationName(indexRel), attno)));
+
+		attr = TupleDescAttr(rel->rd_att, attno - 1);
+		if (!attr->attnotnull)
+			ereport(ERROR,
+					(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+					 errmsg("index \"%s\" cannot be used as replica identity because column \"%s\" is nullable",
+							RelationGetRelationName(indexRel),
+							NameStr(attr->attname))));
+	}
+
+	/* This index is suitable for use as a replica identity. Mark it. */
+	relation_mark_replica_identity(rel, stmt->identity_type, indexOid, true);
+
+	index_close(indexRel, NoLock);
+}
+
+/*
+ * ALTER TABLE ENABLE/DISABLE ROW LEVEL SECURITY
+ */
+static void
+ATExecSetRowSecurity(Relation rel, bool rls)
+{
+	Relation	pg_class;
+	Oid			relid;
+	HeapTuple	tuple;
+
+	relid = RelationGetRelid(rel);
+
+	/* Pull the record for this relation and update it */
+	pg_class = table_open(RelationRelationId, RowExclusiveLock);
+
+	tuple = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(relid));
+
+	if (!HeapTupleIsValid(tuple))
+		elog(ERROR, "cache lookup failed for relation %u", relid);
+
+	((Form_pg_class) GETSTRUCT(tuple))->relrowsecurity = rls;
+	CatalogTupleUpdate(pg_class, &tuple->t_self, tuple);
+
+	table_close(pg_class, RowExclusiveLock);
+	heap_freetuple(tuple);
+}
+
+/*
+ * ALTER TABLE FORCE/NO FORCE ROW LEVEL SECURITY
+ */
+static void
+ATExecForceNoForceRowSecurity(Relation rel, bool force_rls)
+{
+	Relation	pg_class;
+	Oid			relid;
+	HeapTuple	tuple;
+
+	relid = RelationGetRelid(rel);
+
+	pg_class = table_open(RelationRelationId, RowExclusiveLock);
+
+	tuple = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(relid));
+
+	if (!HeapTupleIsValid(tuple))
+		elog(ERROR, "cache lookup failed for relation %u", relid);
+
+	((Form_pg_class) GETSTRUCT(tuple))->relforcerowsecurity = force_rls;
+	CatalogTupleUpdate(pg_class, &tuple->t_self, tuple);
+
+	table_close(pg_class, RowExclusiveLock);
+	heap_freetuple(tuple);
+}
+
+/*
+ * ALTER FOREIGN TABLE <name> OPTIONS (...)
+ */
+static void
+ATExecGenericOptions(Relation rel, List *options)
+{
+	Relation	ftrel;
+	ForeignServer *server;
+	ForeignDataWrapper *fdw;
+	HeapTuple	tuple;
+	bool		isnull;
+	Datum		repl_val[Natts_pg_foreign_table];
+	bool		repl_null[Natts_pg_foreign_table];
+	bool		repl_repl[Natts_pg_foreign_table];
+	Datum		datum;
+	Form_pg_foreign_table tableform;
+
+	if (options == NIL)
+		return;
+
+	ftrel = table_open(ForeignTableRelationId, RowExclusiveLock);
+
+	tuple = SearchSysCacheCopy1(FOREIGNTABLEREL, rel->rd_id);
+	if (!HeapTupleIsValid(tuple))
+		ereport(ERROR,
+				(errcode(ERRCODE_UNDEFINED_OBJECT),
+				 errmsg("foreign table \"%s\" does not exist",
+						RelationGetRelationName(rel))));
+	tableform = (Form_pg_foreign_table) GETSTRUCT(tuple);
+	server = GetForeignServer(tableform->ftserver);
+	fdw = GetForeignDataWrapper(server->fdwid);
+
+	memset(repl_val, 0, sizeof(repl_val));
+	memset(repl_null, false, sizeof(repl_null));
+	memset(repl_repl, false, sizeof(repl_repl));
+
+	/* Extract the current options */
+	datum = SysCacheGetAttr(FOREIGNTABLEREL,
+							tuple,
+							Anum_pg_foreign_table_ftoptions,
+							&isnull);
+	if (isnull)
+		datum = PointerGetDatum(NULL);
+
+	/* Transform the options */
+	datum = transformGenericOptions(ForeignTableRelationId,
+									datum,
+									options,
+									fdw->fdwvalidator);
+
+	if (PointerIsValid(DatumGetPointer(datum)))
+		repl_val[Anum_pg_foreign_table_ftoptions - 1] = datum;
+	else
+		repl_null[Anum_pg_foreign_table_ftoptions - 1] = true;
+
+	repl_repl[Anum_pg_foreign_table_ftoptions - 1] = true;
+
+	/* Everything looks good - update the tuple */
+
+	tuple = heap_modify_tuple(tuple, RelationGetDescr(ftrel),
+							  repl_val, repl_null, repl_repl);
+
+	CatalogTupleUpdate(ftrel, &tuple->t_self, tuple);
+
+	/*
+	 * Invalidate relcache so that all sessions will refresh any cached plans
+	 * that might depend on the old options.
+	 */
+	CacheInvalidateRelcache(rel);
+
+	InvokeObjectPostAlterHook(ForeignTableRelationId,
+							  RelationGetRelid(rel), 0);
+
+	table_close(ftrel, RowExclusiveLock);
+
+	heap_freetuple(tuple);
+}
+
+/*
+ * ALTER TABLE ALTER COLUMN SET COMPRESSION
+ *
+ * Return value is the address of the modified column
+ */
+static ObjectAddress
+ATExecSetCompression(AlteredTableInfo *tab,
+					 Relation rel,
+					 const char *column,
+					 Node *newValue,
+					 LOCKMODE lockmode)
+{
+	Relation	attrel;
+	HeapTuple	tuple;
+	Form_pg_attribute atttableform;
+	AttrNumber	attnum;
+	char	   *compression;
+	char		cmethod;
+	ObjectAddress address;
+
+	Assert(IsA(newValue, String));
+	compression = strVal(newValue);
+
+	attrel = table_open(AttributeRelationId, RowExclusiveLock);
+
+	/* copy the cache entry so we can scribble on it below */
+	tuple = SearchSysCacheCopyAttName(RelationGetRelid(rel), column);
+	if (!HeapTupleIsValid(tuple))
+		ereport(ERROR,
+				(errcode(ERRCODE_UNDEFINED_COLUMN),
+				 errmsg("column \"%s\" of relation \"%s\" does not exist",
+						column, RelationGetRelationName(rel))));
+
+	/* prevent them from altering a system attribute */
+	atttableform = (Form_pg_attribute) GETSTRUCT(tuple);
+	attnum = atttableform->attnum;
+	if (attnum <= 0)
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("cannot alter system column \"%s\"", column)));
+
+	/*
+	 * Check that column type is compressible, then get the attribute
+	 * compression method code
+	 */
+	cmethod = GetAttributeCompression(atttableform->atttypid, compression);
+
+	/* update pg_attribute entry */
+	atttableform->attcompression = cmethod;
+	CatalogTupleUpdate(attrel, &tuple->t_self, tuple);
+
+	InvokeObjectPostAlterHook(RelationRelationId,
+							  RelationGetRelid(rel),
+							  attnum);
+
+	/*
+	 * Apply the change to indexes as well (only for simple index columns,
+	 * matching behavior of index.c ConstructTupleDescriptor()).
+	 */
+	SetIndexStorageProperties(rel, attrel, attnum,
+							  false, 0,
+							  true, cmethod,
+							  lockmode);
+
+	heap_freetuple(tuple);
+
+	table_close(attrel, RowExclusiveLock);
+
+	/* make changes visible */
+	CommandCounterIncrement();
+
+	ObjectAddressSubSet(address, RelationRelationId,
+						RelationGetRelid(rel), attnum);
+	return address;
+}
+
+
+/*
+ * Preparation phase for SET LOGGED/UNLOGGED
+ *
+ * This verifies that we're not trying to change a temp table.  Also,
+ * existing foreign key constraints are checked to avoid ending up with
+ * permanent tables referencing unlogged tables.
+ *
+ * Return value is false if the operation is a no-op (in which case the
+ * checks are skipped), otherwise true.
+ */
+static bool
+ATPrepChangePersistence(Relation rel, bool toLogged)
+{
+	Relation	pg_constraint;
+	HeapTuple	tuple;
+	SysScanDesc scan;
+	ScanKeyData skey[1];
+
+	/*
+	 * Disallow changing status for a temp table.  Also verify whether we can
+	 * get away with doing nothing; in such cases we don't need to run the
+	 * checks below, either.
+	 */
+	switch (rel->rd_rel->relpersistence)
+	{
+		case RELPERSISTENCE_TEMP:
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
+					 errmsg("cannot change logged status of table \"%s\" because it is temporary",
+							RelationGetRelationName(rel)),
+					 errtable(rel)));
+			break;
+		case RELPERSISTENCE_PERMANENT:
+			if (toLogged)
+				/* nothing to do */
+				return false;
+			break;
+		case RELPERSISTENCE_UNLOGGED:
+			if (!toLogged)
+				/* nothing to do */
+				return false;
+			break;
+	}
+
+	/*
+	 * Check that the table is not part any publication when changing to
+	 * UNLOGGED as UNLOGGED tables can't be published.
+	 */
+	if (!toLogged &&
+		list_length(GetRelationPublications(RelationGetRelid(rel))) > 0)
+		ereport(ERROR,
+				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+				 errmsg("cannot change table \"%s\" to unlogged because it is part of a publication",
+						RelationGetRelationName(rel)),
+				 errdetail("Unlogged relations cannot be replicated.")));
+
+	/*
+	 * Check existing foreign key constraints to preserve the invariant that
+	 * permanent tables cannot reference unlogged ones.  Self-referencing
+	 * foreign keys can safely be ignored.
+	 */
+	pg_constraint = table_open(ConstraintRelationId, AccessShareLock);
+
+	/*
+	 * Scan conrelid if changing to permanent, else confrelid.  This also
+	 * determines whether a useful index exists.
+	 */
+	ScanKeyInit(&skey[0],
+				toLogged ? Anum_pg_constraint_conrelid :
+				Anum_pg_constraint_confrelid,
+				BTEqualStrategyNumber, F_OIDEQ,
+				ObjectIdGetDatum(RelationGetRelid(rel)));
+	scan = systable_beginscan(pg_constraint,
+							  toLogged ? ConstraintRelidTypidNameIndexId : InvalidOid,
+							  true, NULL, 1, skey);
+
+	while (HeapTupleIsValid(tuple = systable_getnext(scan)))
+	{
+		Form_pg_constraint con = (Form_pg_constraint) GETSTRUCT(tuple);
+
+		if (con->contype == CONSTRAINT_FOREIGN)
+		{
+			Oid			foreignrelid;
+			Relation	foreignrel;
+
+			/* the opposite end of what we used as scankey */
+			foreignrelid = toLogged ? con->confrelid : con->conrelid;
+
+			/* ignore if self-referencing */
+			if (RelationGetRelid(rel) == foreignrelid)
+				continue;
+
+			foreignrel = relation_open(foreignrelid, AccessShareLock);
+
+			if (toLogged)
+			{
+				if (!RelationIsPermanent(foreignrel))
+					ereport(ERROR,
+							(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
+							 errmsg("could not change table \"%s\" to logged because it references unlogged table \"%s\"",
+									RelationGetRelationName(rel),
+									RelationGetRelationName(foreignrel)),
+							 errtableconstraint(rel, NameStr(con->conname))));
+			}
+			else
+			{
+				if (RelationIsPermanent(foreignrel))
+					ereport(ERROR,
+							(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
+							 errmsg("could not change table \"%s\" to unlogged because it references logged table \"%s\"",
+									RelationGetRelationName(rel),
+									RelationGetRelationName(foreignrel)),
+							 errtableconstraint(rel, NameStr(con->conname))));
+			}
+
+			relation_close(foreignrel, AccessShareLock);
+		}
+	}
+
+	systable_endscan(scan);
+
+	table_close(pg_constraint, AccessShareLock);
+
+	return true;
+}
+
+/*
+ * Execute ALTER TABLE SET SCHEMA
+ */
+ObjectAddress
+AlterTableNamespace(AlterObjectSchemaStmt *stmt, Oid *oldschema)
+{
+	Relation	rel;
+	Oid			relid;
+	Oid			oldNspOid;
+	Oid			nspOid;
+	RangeVar   *newrv;
+	ObjectAddresses *objsMoved;
+	ObjectAddress myself;
+
+	relid = RangeVarGetRelidExtended(stmt->relation, AccessExclusiveLock,
+									 stmt->missing_ok ? RVR_MISSING_OK : 0,
+									 RangeVarCallbackForAlterRelation,
+									 (void *) stmt);
+
+	if (!OidIsValid(relid))
+	{
+		ereport(NOTICE,
+				(errmsg("relation \"%s\" does not exist, skipping",
+						stmt->relation->relname)));
+		return InvalidObjectAddress;
+	}
+
+	rel = relation_open(relid, NoLock);
+
+	oldNspOid = RelationGetNamespace(rel);
+
+	/* If it's an owned sequence, disallow moving it by itself. */
+	if (rel->rd_rel->relkind == RELKIND_SEQUENCE)
+	{
+		Oid			tableId;
+		int32		colId;
+
+		if (sequenceIsOwned(relid, DEPENDENCY_AUTO, &tableId, &colId) ||
+			sequenceIsOwned(relid, DEPENDENCY_INTERNAL, &tableId, &colId))
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("cannot move an owned sequence into another schema"),
+					 errdetail("Sequence \"%s\" is linked to table \"%s\".",
+							   RelationGetRelationName(rel),
+							   get_rel_name(tableId))));
+	}
+
+	/* Get and lock schema OID and check its permissions. */
+	newrv = makeRangeVar(stmt->newschema, RelationGetRelationName(rel), -1);
+	nspOid = RangeVarGetAndCheckCreationNamespace(newrv, NoLock, NULL);
+
+	/* common checks on switching namespaces */
+	CheckSetNamespace(oldNspOid, nspOid);
+
+	objsMoved = new_object_addresses();
+	AlterTableNamespaceInternal(rel, oldNspOid, nspOid, objsMoved);
+	free_object_addresses(objsMoved);
+
+	ObjectAddressSet(myself, RelationRelationId, relid);
+
+	if (oldschema)
+		*oldschema = oldNspOid;
+
+	/* close rel, but keep lock until commit */
+	relation_close(rel, NoLock);
+
+	return myself;
+}
+
+/*
+ * The guts of relocating a table or materialized view to another namespace:
+ * besides moving the relation itself, its dependent objects are relocated to
+ * the new schema.
+ */
+void
+AlterTableNamespaceInternal(Relation rel, Oid oldNspOid, Oid nspOid,
+							ObjectAddresses *objsMoved)
+{
+	Relation	classRel;
+
+	Assert(objsMoved != NULL);
+
+	/* OK, modify the pg_class row and pg_depend entry */
+	classRel = table_open(RelationRelationId, RowExclusiveLock);
+
+	AlterRelationNamespaceInternal(classRel, RelationGetRelid(rel), oldNspOid,
+								   nspOid, true, objsMoved);
+
+	/* Fix the table's row type too, if it has one */
+	if (OidIsValid(rel->rd_rel->reltype))
+		AlterTypeNamespaceInternal(rel->rd_rel->reltype,
+								   nspOid, false, false, objsMoved);
+
+	/* Fix other dependent stuff */
+	if (rel->rd_rel->relkind == RELKIND_RELATION ||
+		rel->rd_rel->relkind == RELKIND_MATVIEW ||
+		rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
+	{
+		AlterIndexNamespaces(classRel, rel, oldNspOid, nspOid, objsMoved);
+		AlterSeqNamespaces(classRel, rel, oldNspOid, nspOid,
+						   objsMoved, AccessExclusiveLock);
+		AlterConstraintNamespaces(RelationGetRelid(rel), oldNspOid, nspOid,
+								  false, objsMoved);
+	}
+
+	table_close(classRel, RowExclusiveLock);
+}
+
+/*
+ * The guts of relocating a relation to another namespace: fix the pg_class
+ * entry, and the pg_depend entry if any.  Caller must already have
+ * opened and write-locked pg_class.
+ */
+void
+AlterRelationNamespaceInternal(Relation classRel, Oid relOid,
+							   Oid oldNspOid, Oid newNspOid,
+							   bool hasDependEntry,
+							   ObjectAddresses *objsMoved)
+{
+	HeapTuple	classTup;
+	Form_pg_class classForm;
+	ObjectAddress thisobj;
+	bool		already_done = false;
+
+	classTup = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(relOid));
+	if (!HeapTupleIsValid(classTup))
+		elog(ERROR, "cache lookup failed for relation %u", relOid);
+	classForm = (Form_pg_class) GETSTRUCT(classTup);
+
+	Assert(classForm->relnamespace == oldNspOid);
+
+	thisobj.classId = RelationRelationId;
+	thisobj.objectId = relOid;
+	thisobj.objectSubId = 0;
+
+	/*
+	 * If the object has already been moved, don't move it again.  If it's
+	 * already in the right place, don't move it, but still fire the object
+	 * access hook.
+	 */
+	already_done = object_address_present(&thisobj, objsMoved);
+	if (!already_done && oldNspOid != newNspOid)
+	{
+		/* check for duplicate name (more friendly than unique-index failure) */
+		if (get_relname_relid(NameStr(classForm->relname),
+							  newNspOid) != InvalidOid)
+			ereport(ERROR,
+					(errcode(ERRCODE_DUPLICATE_TABLE),
+					 errmsg("relation \"%s\" already exists in schema \"%s\"",
+							NameStr(classForm->relname),
+							get_namespace_name(newNspOid))));
+
+		/* classTup is a copy, so OK to scribble on */
+		classForm->relnamespace = newNspOid;
+
+		CatalogTupleUpdate(classRel, &classTup->t_self, classTup);
+
+		/* Update dependency on schema if caller said so */
+		if (hasDependEntry &&
+			changeDependencyFor(RelationRelationId,
+								relOid,
+								NamespaceRelationId,
+								oldNspOid,
+								newNspOid) != 1)
+			elog(ERROR, "failed to change schema dependency for relation \"%s\"",
+				 NameStr(classForm->relname));
+	}
+	if (!already_done)
+	{
+		add_exact_object_address(&thisobj, objsMoved);
+
+		InvokeObjectPostAlterHook(RelationRelationId, relOid, 0);
+	}
+
+	heap_freetuple(classTup);
+}
+
+/*
+ * Move all indexes for the specified relation to another namespace.
+ *
+ * Note: we assume adequate permission checking was done by the caller,
+ * and that the caller has a suitable lock on the owning relation.
+ */
+static void
+AlterIndexNamespaces(Relation classRel, Relation rel,
+					 Oid oldNspOid, Oid newNspOid, ObjectAddresses *objsMoved)
+{
+	List	   *indexList;
+	ListCell   *l;
+
+	indexList = RelationGetIndexList(rel);
+
+	foreach(l, indexList)
+	{
+		Oid			indexOid = lfirst_oid(l);
+		ObjectAddress thisobj;
+
+		thisobj.classId = RelationRelationId;
+		thisobj.objectId = indexOid;
+		thisobj.objectSubId = 0;
+
+		/*
+		 * Note: currently, the index will not have its own dependency on the
+		 * namespace, so we don't need to do changeDependencyFor(). There's no
+		 * row type in pg_type, either.
+		 *
+		 * XXX this objsMoved test may be pointless -- surely we have a single
+		 * dependency link from a relation to each index?
+		 */
+		if (!object_address_present(&thisobj, objsMoved))
+		{
+			AlterRelationNamespaceInternal(classRel, indexOid,
+										   oldNspOid, newNspOid,
+										   false, objsMoved);
+			add_exact_object_address(&thisobj, objsMoved);
+		}
+	}
+
+	list_free(indexList);
+}
+
+/*
+ * Move all identity and SERIAL-column sequences of the specified relation to another
+ * namespace.
+ *
+ * Note: we assume adequate permission checking was done by the caller,
+ * and that the caller has a suitable lock on the owning relation.
+ */
+static void
+AlterSeqNamespaces(Relation classRel, Relation rel,
+				   Oid oldNspOid, Oid newNspOid, ObjectAddresses *objsMoved,
+				   LOCKMODE lockmode)
+{
+	Relation	depRel;
+	SysScanDesc scan;
+	ScanKeyData key[2];
+	HeapTuple	tup;
+
+	/*
+	 * SERIAL sequences are those having an auto dependency on one of the
+	 * table's columns (we don't care *which* column, exactly).
+	 */
+	depRel = table_open(DependRelationId, AccessShareLock);
+
+	ScanKeyInit(&key[0],
+				Anum_pg_depend_refclassid,
+				BTEqualStrategyNumber, F_OIDEQ,
+				ObjectIdGetDatum(RelationRelationId));
+	ScanKeyInit(&key[1],
+				Anum_pg_depend_refobjid,
+				BTEqualStrategyNumber, F_OIDEQ,
+				ObjectIdGetDatum(RelationGetRelid(rel)));
+	/* we leave refobjsubid unspecified */
+
+	scan = systable_beginscan(depRel, DependReferenceIndexId, true,
+							  NULL, 2, key);
+
+	while (HeapTupleIsValid(tup = systable_getnext(scan)))
+	{
+		Form_pg_depend depForm = (Form_pg_depend) GETSTRUCT(tup);
+		Relation	seqRel;
+
+		/* skip dependencies other than auto dependencies on columns */
+		if (depForm->refobjsubid == 0 ||
+			depForm->classid != RelationRelationId ||
+			depForm->objsubid != 0 ||
+			!(depForm->deptype == DEPENDENCY_AUTO || depForm->deptype == DEPENDENCY_INTERNAL))
+			continue;
+
+		/* Use relation_open just in case it's an index */
+		seqRel = relation_open(depForm->objid, lockmode);
+
+		/* skip non-sequence relations */
+		if (RelationGetForm(seqRel)->relkind != RELKIND_SEQUENCE)
+		{
+			/* No need to keep the lock */
+			relation_close(seqRel, lockmode);
+			continue;
+		}
+
+		/* Fix the pg_class and pg_depend entries */
+		AlterRelationNamespaceInternal(classRel, depForm->objid,
+									   oldNspOid, newNspOid,
+									   true, objsMoved);
+
+		/*
+		 * Sequences used to have entries in pg_type, but no longer do.  If we
+		 * ever re-instate that, we'll need to move the pg_type entry to the
+		 * new namespace, too (using AlterTypeNamespaceInternal).
+		 */
+		Assert(RelationGetForm(seqRel)->reltype == InvalidOid);
+
+		/* Now we can close it.  Keep the lock till end of transaction. */
+		relation_close(seqRel, NoLock);
+	}
+
+	systable_endscan(scan);
+
+	relation_close(depRel, AccessShareLock);
+}
+
+
+/*
+ * This code supports
+ *	CREATE TEMP TABLE ... ON COMMIT { DROP | PRESERVE ROWS | DELETE ROWS }
+ *
+ * Because we only support this for TEMP tables, it's sufficient to remember
+ * the state in a backend-local data structure.
+ */
+
+/*
+ * Register a newly-created relation's ON COMMIT action.
+ */
+void
+register_on_commit_action(Oid relid, OnCommitAction action)
+{
+	OnCommitItem *oc;
+	MemoryContext oldcxt;
+
+	/*
+	 * We needn't bother registering the relation unless there is an ON COMMIT
+	 * action we need to take.
+	 */
+	if (action == ONCOMMIT_NOOP || action == ONCOMMIT_PRESERVE_ROWS)
+		return;
+
+	oldcxt = MemoryContextSwitchTo(CacheMemoryContext);
+
+	oc = (OnCommitItem *) palloc(sizeof(OnCommitItem));
+	oc->relid = relid;
+	oc->oncommit = action;
+	oc->creating_subid = GetCurrentSubTransactionId();
+	oc->deleting_subid = InvalidSubTransactionId;
+
+	/*
+	 * We use lcons() here so that ON COMMIT actions are processed in reverse
+	 * order of registration.  That might not be essential but it seems
+	 * reasonable.
+	 */
+	on_commits = lcons(oc, on_commits);
+
+	MemoryContextSwitchTo(oldcxt);
+}
+
+/*
+ * Unregister any ON COMMIT action when a relation is deleted.
+ *
+ * Actually, we only mark the OnCommitItem entry as to be deleted after commit.
+ */
+void
+remove_on_commit_action(Oid relid)
+{
+	ListCell   *l;
+
+	foreach(l, on_commits)
+	{
+		OnCommitItem *oc = (OnCommitItem *) lfirst(l);
+
+		if (oc->relid == relid)
+		{
+			oc->deleting_subid = GetCurrentSubTransactionId();
+			break;
+		}
+	}
+}
+
+/*
+ * Perform ON COMMIT actions.
+ *
+ * This is invoked just before actually committing, since it's possible
+ * to encounter errors.
+ */
+void
+PreCommit_on_commit_actions(void)
+{
+	ListCell   *l;
+	List	   *oids_to_truncate = NIL;
+	List	   *oids_to_drop = NIL;
+
+	foreach(l, on_commits)
+	{
+		OnCommitItem *oc = (OnCommitItem *) lfirst(l);
+
+		/* Ignore entry if already dropped in this xact */
+		if (oc->deleting_subid != InvalidSubTransactionId)
+			continue;
+
+		switch (oc->oncommit)
+		{
+			case ONCOMMIT_NOOP:
+			case ONCOMMIT_PRESERVE_ROWS:
+				/* Do nothing (there shouldn't be such entries, actually) */
+				break;
+			case ONCOMMIT_DELETE_ROWS:
+
+				/*
+				 * If this transaction hasn't accessed any temporary
+				 * relations, we can skip truncating ON COMMIT DELETE ROWS
+				 * tables, as they must still be empty.
+				 */
+				if ((MyXactFlags & XACT_FLAGS_ACCESSEDTEMPNAMESPACE))
+					oids_to_truncate = lappend_oid(oids_to_truncate, oc->relid);
+				break;
+			case ONCOMMIT_DROP:
+				oids_to_drop = lappend_oid(oids_to_drop, oc->relid);
+				break;
+		}
+	}
+
+	/*
+	 * Truncate relations before dropping so that all dependencies between
+	 * relations are removed after they are worked on.  Doing it like this
+	 * might be a waste as it is possible that a relation being truncated will
+	 * be dropped anyway due to its parent being dropped, but this makes the
+	 * code more robust because of not having to re-check that the relation
+	 * exists at truncation time.
+	 */
+	if (oids_to_truncate != NIL)
+		heap_truncate(oids_to_truncate);
+
+	if (oids_to_drop != NIL)
+	{
+		ObjectAddresses *targetObjects = new_object_addresses();
+		ListCell   *l;
+
+		foreach(l, oids_to_drop)
+		{
+			ObjectAddress object;
+
+			object.classId = RelationRelationId;
+			object.objectId = lfirst_oid(l);
+			object.objectSubId = 0;
+
+			Assert(!object_address_present(&object, targetObjects));
+
+			add_exact_object_address(&object, targetObjects);
+		}
+
+		/*
+		 * Object deletion might involve toast table access (to clean up
+		 * toasted catalog entries), so ensure we have a valid snapshot.
+		 */
+		PushActiveSnapshot(GetTransactionSnapshot());
+
+		/*
+		 * Since this is an automatic drop, rather than one directly initiated
+		 * by the user, we pass the PERFORM_DELETION_INTERNAL flag.
+		 */
+		performMultipleDeletions(targetObjects, DROP_CASCADE,
+								 PERFORM_DELETION_INTERNAL | PERFORM_DELETION_QUIETLY);
+
+		PopActiveSnapshot();
+
+#ifdef USE_ASSERT_CHECKING
+
+		/*
+		 * Note that table deletion will call remove_on_commit_action, so the
+		 * entry should get marked as deleted.
+		 */
+		foreach(l, on_commits)
+		{
+			OnCommitItem *oc = (OnCommitItem *) lfirst(l);
+
+			if (oc->oncommit != ONCOMMIT_DROP)
+				continue;
+
+			Assert(oc->deleting_subid != InvalidSubTransactionId);
+		}
+#endif
+	}
+}
+
+/*
+ * Post-commit or post-abort cleanup for ON COMMIT management.
+ *
+ * All we do here is remove no-longer-needed OnCommitItem entries.
+ *
+ * During commit, remove entries that were deleted during this transaction;
+ * during abort, remove those created during this transaction.
+ */
+void
+AtEOXact_on_commit_actions(bool isCommit)
+{
+	ListCell   *cur_item;
+
+	foreach(cur_item, on_commits)
+	{
+		OnCommitItem *oc = (OnCommitItem *) lfirst(cur_item);
+
+		if (isCommit ? oc->deleting_subid != InvalidSubTransactionId :
+			oc->creating_subid != InvalidSubTransactionId)
+		{
+			/* cur_item must be removed */
+			on_commits = foreach_delete_current(on_commits, cur_item);
+			pfree(oc);
+		}
+		else
+		{
+			/* cur_item must be preserved */
+			oc->creating_subid = InvalidSubTransactionId;
+			oc->deleting_subid = InvalidSubTransactionId;
+		}
+	}
+}
+
+/*
+ * Post-subcommit or post-subabort cleanup for ON COMMIT management.
+ *
+ * During subabort, we can immediately remove entries created during this
+ * subtransaction.  During subcommit, just relabel entries marked during
+ * this subtransaction as being the parent's responsibility.
+ */
+void
+AtEOSubXact_on_commit_actions(bool isCommit, SubTransactionId mySubid,
+							  SubTransactionId parentSubid)
+{
+	ListCell   *cur_item;
+
+	foreach(cur_item, on_commits)
+	{
+		OnCommitItem *oc = (OnCommitItem *) lfirst(cur_item);
+
+		if (!isCommit && oc->creating_subid == mySubid)
+		{
+			/* cur_item must be removed */
+			on_commits = foreach_delete_current(on_commits, cur_item);
+			pfree(oc);
+		}
+		else
+		{
+			/* cur_item must be preserved */
+			if (oc->creating_subid == mySubid)
+				oc->creating_subid = parentSubid;
+			if (oc->deleting_subid == mySubid)
+				oc->deleting_subid = isCommit ? parentSubid : InvalidSubTransactionId;
+		}
+	}
+}
+
+/*
+ * This is intended as a callback for RangeVarGetRelidExtended().  It allows
+ * the relation to be locked only if (1) it's a plain or partitioned table,
+ * materialized view, or TOAST table and (2) the current user is the owner (or
+ * the superuser).  This meets the permission-checking needs of CLUSTER,
+ * REINDEX TABLE, and REFRESH MATERIALIZED VIEW; we expose it here so that it
+ * can be used by all.
+ */
+void
+RangeVarCallbackOwnsTable(const RangeVar *relation,
+						  Oid relId, Oid oldRelId, void *arg)
+{
+	char		relkind;
+
+	/* Nothing to do if the relation was not found. */
+	if (!OidIsValid(relId))
+		return;
+
+	/*
+	 * If the relation does exist, check whether it's an index.  But note that
+	 * the relation might have been dropped between the time we did the name
+	 * lookup and now.  In that case, there's nothing to do.
+	 */
+	relkind = get_rel_relkind(relId);
+	if (!relkind)
+		return;
+	if (relkind != RELKIND_RELATION && relkind != RELKIND_TOASTVALUE &&
+		relkind != RELKIND_MATVIEW && relkind != RELKIND_PARTITIONED_TABLE)
+		ereport(ERROR,
+				(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+				 errmsg("\"%s\" is not a table or materialized view", relation->relname)));
+
+	/* Check permissions */
+	if (!pg_class_ownercheck(relId, GetUserId()))
+		aclcheck_error(ACLCHECK_NOT_OWNER, get_relkind_objtype(get_rel_relkind(relId)), relation->relname);
+}
+
+/*
+ * Callback to RangeVarGetRelidExtended() for TRUNCATE processing.
+ */
+static void
+RangeVarCallbackForTruncate(const RangeVar *relation,
+							Oid relId, Oid oldRelId, void *arg)
+{
+	HeapTuple	tuple;
+
+	/* Nothing to do if the relation was not found. */
+	if (!OidIsValid(relId))
+		return;
+
+	tuple = SearchSysCache1(RELOID, ObjectIdGetDatum(relId));
+	if (!HeapTupleIsValid(tuple))	/* should not happen */
+		elog(ERROR, "cache lookup failed for relation %u", relId);
+
+	truncate_check_rel(relId, (Form_pg_class) GETSTRUCT(tuple));
+	truncate_check_perms(relId, (Form_pg_class) GETSTRUCT(tuple));
+
+	ReleaseSysCache(tuple);
+}
+
+/*
+ * Callback to RangeVarGetRelidExtended(), similar to
+ * RangeVarCallbackOwnsTable() but without checks on the type of the relation.
+ */
+void
+RangeVarCallbackOwnsRelation(const RangeVar *relation,
+							 Oid relId, Oid oldRelId, void *arg)
+{
+	HeapTuple	tuple;
+
+	/* Nothing to do if the relation was not found. */
+	if (!OidIsValid(relId))
+		return;
+
+	tuple = SearchSysCache1(RELOID, ObjectIdGetDatum(relId));
+	if (!HeapTupleIsValid(tuple))	/* should not happen */
+		elog(ERROR, "cache lookup failed for relation %u", relId);
+
+	if (!pg_class_ownercheck(relId, GetUserId()))
+		aclcheck_error(ACLCHECK_NOT_OWNER, get_relkind_objtype(get_rel_relkind(relId)),
+					   relation->relname);
+
+	if (!allowSystemTableMods &&
+		IsSystemClass(relId, (Form_pg_class) GETSTRUCT(tuple)))
+		ereport(ERROR,
+				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
+				 errmsg("permission denied: \"%s\" is a system catalog",
+						relation->relname)));
+
+	ReleaseSysCache(tuple);
+}
+
+/*
+ * Common RangeVarGetRelid callback for rename, set schema, and alter table
+ * processing.
+ */
+static void
+RangeVarCallbackForAlterRelation(const RangeVar *rv, Oid relid, Oid oldrelid,
+								 void *arg)
+{
+	Node	   *stmt = (Node *) arg;
+	ObjectType	reltype;
+	HeapTuple	tuple;
+	Form_pg_class classform;
+	AclResult	aclresult;
+	char		relkind;
+
+	tuple = SearchSysCache1(RELOID, ObjectIdGetDatum(relid));
+	if (!HeapTupleIsValid(tuple))
+		return;					/* concurrently dropped */
+	classform = (Form_pg_class) GETSTRUCT(tuple);
+	relkind = classform->relkind;
+
+	/* Must own relation. */
+	if (!pg_class_ownercheck(relid, GetUserId()))
+		aclcheck_error(ACLCHECK_NOT_OWNER, get_relkind_objtype(get_rel_relkind(relid)), rv->relname);
+
+	/* No system table modifications unless explicitly allowed. */
+	if (!allowSystemTableMods && IsSystemClass(relid, classform))
+		ereport(ERROR,
+				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
+				 errmsg("permission denied: \"%s\" is a system catalog",
+						rv->relname)));
+
+	/*
+	 * Extract the specified relation type from the statement parse tree.
+	 *
+	 * Also, for ALTER .. RENAME, check permissions: the user must (still)
+	 * have CREATE rights on the containing namespace.
+	 */
+	if (IsA(stmt, RenameStmt))
+	{
+		aclresult = pg_namespace_aclcheck(classform->relnamespace,
+										  GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_SCHEMA,
+						   get_namespace_name(classform->relnamespace));
+		reltype = ((RenameStmt *) stmt)->renameType;
+	}
+	else if (IsA(stmt, AlterObjectSchemaStmt))
+		reltype = ((AlterObjectSchemaStmt *) stmt)->objectType;
+
+	else if (IsA(stmt, AlterTableStmt))
+		reltype = ((AlterTableStmt *) stmt)->objtype;
+	else
+	{
+		elog(ERROR, "unrecognized node type: %d", (int) nodeTag(stmt));
+		reltype = OBJECT_TABLE; /* placate compiler */
+	}
+
+	/*
+	 * For compatibility with prior releases, we allow ALTER TABLE to be used
+	 * with most other types of relations (but not composite types). We allow
+	 * similar flexibility for ALTER INDEX in the case of RENAME, but not
+	 * otherwise.  Otherwise, the user must select the correct form of the
+	 * command for the relation at issue.
+	 */
+	if (reltype == OBJECT_SEQUENCE && relkind != RELKIND_SEQUENCE)
+		ereport(ERROR,
+				(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+				 errmsg("\"%s\" is not a sequence", rv->relname)));
+
+	if (reltype == OBJECT_VIEW && relkind != RELKIND_VIEW)
+		ereport(ERROR,
+				(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+				 errmsg("\"%s\" is not a view", rv->relname)));
+
+	if (reltype == OBJECT_MATVIEW && relkind != RELKIND_MATVIEW)
+		ereport(ERROR,
+				(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+				 errmsg("\"%s\" is not a materialized view", rv->relname)));
+
+	if (reltype == OBJECT_FOREIGN_TABLE && relkind != RELKIND_FOREIGN_TABLE)
+		ereport(ERROR,
+				(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+				 errmsg("\"%s\" is not a foreign table", rv->relname)));
+
+	if (reltype == OBJECT_TYPE && relkind != RELKIND_COMPOSITE_TYPE)
+		ereport(ERROR,
+				(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+				 errmsg("\"%s\" is not a composite type", rv->relname)));
+
+	if (reltype == OBJECT_INDEX && relkind != RELKIND_INDEX &&
+		relkind != RELKIND_PARTITIONED_INDEX
+		&& !IsA(stmt, RenameStmt))
+		ereport(ERROR,
+				(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+				 errmsg("\"%s\" is not an index", rv->relname)));
+
+	/*
+	 * Don't allow ALTER TABLE on composite types. We want people to use ALTER
+	 * TYPE for that.
+	 */
+	if (reltype != OBJECT_TYPE && relkind == RELKIND_COMPOSITE_TYPE)
+		ereport(ERROR,
+				(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+				 errmsg("\"%s\" is a composite type", rv->relname),
+				 errhint("Use ALTER TYPE instead.")));
+
+	/*
+	 * Don't allow ALTER TABLE .. SET SCHEMA on relations that can't be moved
+	 * to a different schema, such as indexes and TOAST tables.
+	 */
+	if (IsA(stmt, AlterObjectSchemaStmt))
+	{
+		if (relkind == RELKIND_INDEX || relkind == RELKIND_PARTITIONED_INDEX)
+			ereport(ERROR,
+					(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+					 errmsg("cannot change schema of index \"%s\"",
+							rv->relname),
+					 errhint("Change the schema of the table instead.")));
+		else if (relkind == RELKIND_COMPOSITE_TYPE)
+			ereport(ERROR,
+					(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+					 errmsg("cannot change schema of composite type \"%s\"",
+							rv->relname),
+					 errhint("Use ALTER TYPE instead.")));
+		else if (relkind == RELKIND_TOASTVALUE)
+			ereport(ERROR,
+					(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+					 errmsg("cannot change schema of TOAST table \"%s\"",
+							rv->relname),
+					 errhint("Change the schema of the table instead.")));
+	}
+
+	ReleaseSysCache(tuple);
+}
+
+/*
+ * Transform any expressions present in the partition key
+ *
+ * Returns a transformed PartitionSpec, as well as the strategy code
+ */
+static PartitionSpec *
+transformPartitionSpec(Relation rel, PartitionSpec *partspec, char *strategy)
+{
+	PartitionSpec *newspec;
+	ParseState *pstate;
+	ParseNamespaceItem *nsitem;
+	ListCell   *l;
+
+	newspec = makeNode(PartitionSpec);
+
+	newspec->strategy = partspec->strategy;
+	newspec->partParams = NIL;
+	newspec->location = partspec->location;
+
+	/* Parse partitioning strategy name */
+	if (pg_strcasecmp(partspec->strategy, "hash") == 0)
+		*strategy = PARTITION_STRATEGY_HASH;
+	else if (pg_strcasecmp(partspec->strategy, "list") == 0)
+		*strategy = PARTITION_STRATEGY_LIST;
+	else if (pg_strcasecmp(partspec->strategy, "range") == 0)
+		*strategy = PARTITION_STRATEGY_RANGE;
+	else
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("unrecognized partitioning strategy \"%s\"",
+						partspec->strategy)));
+
+	/* Check valid number of columns for strategy */
+	if (*strategy == PARTITION_STRATEGY_LIST &&
+		list_length(partspec->partParams) != 1)
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
+				 errmsg("cannot use \"list\" partition strategy with more than one column")));
+
+	/*
+	 * Create a dummy ParseState and insert the target relation as its sole
+	 * rangetable entry.  We need a ParseState for transformExpr.
+	 */
+	pstate = make_parsestate(NULL);
+	nsitem = addRangeTableEntryForRelation(pstate, rel, AccessShareLock,
+										   NULL, false, true);
+	addNSItemToQuery(pstate, nsitem, true, true, true);
+
+	/* take care of any partition expressions */
+	foreach(l, partspec->partParams)
+	{
+		PartitionElem *pelem = lfirst_node(PartitionElem, l);
+
+		if (pelem->expr)
+		{
+			/* Copy, to avoid scribbling on the input */
+			pelem = copyObject(pelem);
+
+			/* Now do parse transformation of the expression */
+			pelem->expr = transformExpr(pstate, pelem->expr,
+										EXPR_KIND_PARTITION_EXPRESSION);
+
+			/* we have to fix its collations too */
+			assign_expr_collations(pstate, pelem->expr);
+		}
+
+		newspec->partParams = lappend(newspec->partParams, pelem);
+	}
+
+	return newspec;
+}
+
+/*
+ * Compute per-partition-column information from a list of PartitionElems.
+ * Expressions in the PartitionElems must be parse-analyzed already.
+ */
+static void
+ComputePartitionAttrs(ParseState *pstate, Relation rel, List *partParams, AttrNumber *partattrs,
+					  List **partexprs, Oid *partopclass, Oid *partcollation,
+					  char strategy)
+{
+	int			attn;
+	ListCell   *lc;
+	Oid			am_oid;
+
+	attn = 0;
+	foreach(lc, partParams)
+	{
+		PartitionElem *pelem = lfirst_node(PartitionElem, lc);
+		Oid			atttype;
+		Oid			attcollation;
+
+		if (pelem->name != NULL)
+		{
+			/* Simple attribute reference */
+			HeapTuple	atttuple;
+			Form_pg_attribute attform;
+
+			atttuple = SearchSysCacheAttName(RelationGetRelid(rel),
+											 pelem->name);
+			if (!HeapTupleIsValid(atttuple))
+				ereport(ERROR,
+						(errcode(ERRCODE_UNDEFINED_COLUMN),
+						 errmsg("column \"%s\" named in partition key does not exist",
+								pelem->name),
+						 parser_errposition(pstate, pelem->location)));
+			attform = (Form_pg_attribute) GETSTRUCT(atttuple);
+
+			if (attform->attnum <= 0)
+				ereport(ERROR,
+						(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
+						 errmsg("cannot use system column \"%s\" in partition key",
+								pelem->name),
+						 parser_errposition(pstate, pelem->location)));
+
+			/*
+			 * Generated columns cannot work: They are computed after BEFORE
+			 * triggers, but partition routing is done before all triggers.
+			 */
+			if (attform->attgenerated)
+				ereport(ERROR,
+						(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
+						 errmsg("cannot use generated column in partition key"),
+						 errdetail("Column \"%s\" is a generated column.",
+								   pelem->name),
+						 parser_errposition(pstate, pelem->location)));
+
+			partattrs[attn] = attform->attnum;
+			atttype = attform->atttypid;
+			attcollation = attform->attcollation;
+			ReleaseSysCache(atttuple);
+		}
+		else
+		{
+			/* Expression */
+			Node	   *expr = pelem->expr;
+			char		partattname[16];
+
+			Assert(expr != NULL);
+			atttype = exprType(expr);
+			attcollation = exprCollation(expr);
+
+			/*
+			 * The expression must be of a storable type (e.g., not RECORD).
+			 * The test is the same as for whether a table column is of a safe
+			 * type (which is why we needn't check for the non-expression
+			 * case).
+			 */
+			snprintf(partattname, sizeof(partattname), "%d", attn + 1);
+			CheckAttributeType(partattname,
+							   atttype, attcollation,
+							   NIL, CHKATYPE_IS_PARTKEY);
+
+			/*
+			 * Strip any top-level COLLATE clause.  This ensures that we treat
+			 * "x COLLATE y" and "(x COLLATE y)" alike.
+			 */
+			while (IsA(expr, CollateExpr))
+				expr = (Node *) ((CollateExpr *) expr)->arg;
+
+			if (IsA(expr, Var) &&
+				((Var *) expr)->varattno > 0)
+			{
+				/*
+				 * User wrote "(column)" or "(column COLLATE something)".
+				 * Treat it like simple attribute anyway.
+				 */
+				partattrs[attn] = ((Var *) expr)->varattno;
+			}
+			else
+			{
+				Bitmapset  *expr_attrs = NULL;
+				int			i;
+
+				partattrs[attn] = 0;	/* marks the column as expression */
+				*partexprs = lappend(*partexprs, expr);
+
+				/*
+				 * Try to simplify the expression before checking for
+				 * mutability.  The main practical value of doing it in this
+				 * order is that an inline-able SQL-language function will be
+				 * accepted if its expansion is immutable, whether or not the
+				 * function itself is marked immutable.
+				 *
+				 * Note that expression_planner does not change the passed in
+				 * expression destructively and we have already saved the
+				 * expression to be stored into the catalog above.
+				 */
+				expr = (Node *) expression_planner((Expr *) expr);
+
+				/*
+				 * Partition expression cannot contain mutable functions,
+				 * because a given row must always map to the same partition
+				 * as long as there is no change in the partition boundary
+				 * structure.
+				 */
+				if (contain_mutable_functions(expr))
+					ereport(ERROR,
+							(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
+							 errmsg("functions in partition key expression must be marked IMMUTABLE")));
+
+				/*
+				 * transformPartitionSpec() should have already rejected
+				 * subqueries, aggregates, window functions, and SRFs, based
+				 * on the EXPR_KIND_ for partition expressions.
+				 */
+
+				/*
+				 * Cannot allow system column references, since that would
+				 * make partition routing impossible: their values won't be
+				 * known yet when we need to do that.
+				 */
+				pull_varattnos(expr, 1, &expr_attrs);
+				for (i = FirstLowInvalidHeapAttributeNumber; i < 0; i++)
+				{
+					if (bms_is_member(i - FirstLowInvalidHeapAttributeNumber,
+									  expr_attrs))
+						ereport(ERROR,
+								(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
+								 errmsg("partition key expressions cannot contain system column references")));
+				}
+
+				/*
+				 * Generated columns cannot work: They are computed after
+				 * BEFORE triggers, but partition routing is done before all
+				 * triggers.
+				 */
+				i = -1;
+				while ((i = bms_next_member(expr_attrs, i)) >= 0)
+				{
+					AttrNumber	attno = i + FirstLowInvalidHeapAttributeNumber;
+
+					if (attno > 0 &&
+						TupleDescAttr(RelationGetDescr(rel), attno - 1)->attgenerated)
+						ereport(ERROR,
+								(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
+								 errmsg("cannot use generated column in partition key"),
+								 errdetail("Column \"%s\" is a generated column.",
+										   get_attname(RelationGetRelid(rel), attno, false)),
+								 parser_errposition(pstate, pelem->location)));
+				}
+
+				/*
+				 * While it is not exactly *wrong* for a partition expression
+				 * to be a constant, it seems better to reject such keys.
+				 */
+				if (IsA(expr, Const))
+					ereport(ERROR,
+							(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
+							 errmsg("cannot use constant expression as partition key")));
+			}
+		}
+
+		/*
+		 * Apply collation override if any
+		 */
+		if (pelem->collation)
+			attcollation = get_collation_oid(pelem->collation, false);
+
+		/*
+		 * Check we have a collation iff it's a collatable type.  The only
+		 * expected failures here are (1) COLLATE applied to a noncollatable
+		 * type, or (2) partition expression had an unresolved collation. But
+		 * we might as well code this to be a complete consistency check.
+		 */
+		if (type_is_collatable(atttype))
+		{
+			if (!OidIsValid(attcollation))
+				ereport(ERROR,
+						(errcode(ERRCODE_INDETERMINATE_COLLATION),
+						 errmsg("could not determine which collation to use for partition expression"),
+						 errhint("Use the COLLATE clause to set the collation explicitly.")));
+		}
+		else
+		{
+			if (OidIsValid(attcollation))
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("collations are not supported by type %s",
+								format_type_be(atttype))));
+		}
+
+		partcollation[attn] = attcollation;
+
+		/*
+		 * Identify the appropriate operator class.  For list and range
+		 * partitioning, we use a btree operator class; hash partitioning uses
+		 * a hash operator class.
+		 */
+		if (strategy == PARTITION_STRATEGY_HASH)
+			am_oid = HASH_AM_OID;
+		else
+			am_oid = BTREE_AM_OID;
+
+		if (!pelem->opclass)
+		{
+			partopclass[attn] = GetDefaultOpClass(atttype, am_oid);
+
+			if (!OidIsValid(partopclass[attn]))
+			{
+				if (strategy == PARTITION_STRATEGY_HASH)
+					ereport(ERROR,
+							(errcode(ERRCODE_UNDEFINED_OBJECT),
+							 errmsg("data type %s has no default operator class for access method \"%s\"",
+									format_type_be(atttype), "hash"),
+							 errhint("You must specify a hash operator class or define a default hash operator class for the data type.")));
+				else
+					ereport(ERROR,
+							(errcode(ERRCODE_UNDEFINED_OBJECT),
+							 errmsg("data type %s has no default operator class for access method \"%s\"",
+									format_type_be(atttype), "btree"),
+							 errhint("You must specify a btree operator class or define a default btree operator class for the data type.")));
+			}
+		}
+		else
+			partopclass[attn] = ResolveOpClass(pelem->opclass,
+											   atttype,
+											   am_oid == HASH_AM_OID ? "hash" : "btree",
+											   am_oid);
+
+		attn++;
+	}
+}
+
+/*
+ * PartConstraintImpliedByRelConstraint
+ *		Do scanrel's existing constraints imply the partition constraint?
+ *
+ * "Existing constraints" include its check constraints and column-level
+ * NOT NULL constraints.  partConstraint describes the partition constraint,
+ * in implicit-AND form.
+ */
+bool
+PartConstraintImpliedByRelConstraint(Relation scanrel,
+									 List *partConstraint)
+{
+	List	   *existConstraint = NIL;
+	TupleConstr *constr = RelationGetDescr(scanrel)->constr;
+	int			i;
+
+	if (constr && constr->has_not_null)
+	{
+		int			natts = scanrel->rd_att->natts;
+
+		for (i = 1; i <= natts; i++)
+		{
+			Form_pg_attribute att = TupleDescAttr(scanrel->rd_att, i - 1);
+
+			if (att->attnotnull && !att->attisdropped)
+			{
+				NullTest   *ntest = makeNode(NullTest);
+
+				ntest->arg = (Expr *) makeVar(1,
+											  i,
+											  att->atttypid,
+											  att->atttypmod,
+											  att->attcollation,
+											  0);
+				ntest->nulltesttype = IS_NOT_NULL;
+
+				/*
+				 * argisrow=false is correct even for a composite column,
+				 * because attnotnull does not represent a SQL-spec IS NOT
+				 * NULL test in such a case, just IS DISTINCT FROM NULL.
+				 */
+				ntest->argisrow = false;
+				ntest->location = -1;
+				existConstraint = lappend(existConstraint, ntest);
+			}
+		}
+	}
+
+	return ConstraintImpliedByRelConstraint(scanrel, partConstraint, existConstraint);
+}
+
+/*
+ * ConstraintImpliedByRelConstraint
+ *		Do scanrel's existing constraints imply the given constraint?
+ *
+ * testConstraint is the constraint to validate. provenConstraint is a
+ * caller-provided list of conditions which this function may assume
+ * to be true. Both provenConstraint and testConstraint must be in
+ * implicit-AND form, must only contain immutable clauses, and must
+ * contain only Vars with varno = 1.
+ */
+bool
+ConstraintImpliedByRelConstraint(Relation scanrel, List *testConstraint, List *provenConstraint)
+{
+	List	   *existConstraint = list_copy(provenConstraint);
+	TupleConstr *constr = RelationGetDescr(scanrel)->constr;
+	int			num_check,
+				i;
+
+	num_check = (constr != NULL) ? constr->num_check : 0;
+	for (i = 0; i < num_check; i++)
+	{
+		Node	   *cexpr;
+
+		/*
+		 * If this constraint hasn't been fully validated yet, we must ignore
+		 * it here.
+		 */
+		if (!constr->check[i].ccvalid)
+			continue;
+
+		cexpr = stringToNode(constr->check[i].ccbin);
+
+		/*
+		 * Run each expression through const-simplification and
+		 * canonicalization.  It is necessary, because we will be comparing it
+		 * to similarly-processed partition constraint expressions, and may
+		 * fail to detect valid matches without this.
+		 */
+		cexpr = eval_const_expressions(NULL, cexpr);
+		cexpr = (Node *) canonicalize_qual((Expr *) cexpr, true);
+
+		existConstraint = list_concat(existConstraint,
+									  make_ands_implicit((Expr *) cexpr));
+	}
+
+	/*
+	 * Try to make the proof.  Since we are comparing CHECK constraints, we
+	 * need to use weak implication, i.e., we assume existConstraint is
+	 * not-false and try to prove the same for testConstraint.
+	 *
+	 * Note that predicate_implied_by assumes its first argument is known
+	 * immutable.  That should always be true for both NOT NULL and partition
+	 * constraints, so we don't test it here.
+	 */
+	return predicate_implied_by(testConstraint, existConstraint, true);
+}
+
+/*
+ * QueuePartitionConstraintValidation
+ *
+ * Add an entry to wqueue to have the given partition constraint validated by
+ * Phase 3, for the given relation, and all its children.
+ *
+ * We first verify whether the given constraint is implied by pre-existing
+ * relation constraints; if it is, there's no need to scan the table to
+ * validate, so don't queue in that case.
+ */
+static void
+QueuePartitionConstraintValidation(List **wqueue, Relation scanrel,
+								   List *partConstraint,
+								   bool validate_default)
+{
+	/*
+	 * Based on the table's existing constraints, determine whether or not we
+	 * may skip scanning the table.
+	 */
+	if (PartConstraintImpliedByRelConstraint(scanrel, partConstraint))
+	{
+		if (!validate_default)
+			ereport(DEBUG1,
+					(errmsg_internal("partition constraint for table \"%s\" is implied by existing constraints",
+									 RelationGetRelationName(scanrel))));
+		else
+			ereport(DEBUG1,
+					(errmsg_internal("updated partition constraint for default partition \"%s\" is implied by existing constraints",
+									 RelationGetRelationName(scanrel))));
+		return;
+	}
+
+	/*
+	 * Constraints proved insufficient. For plain relations, queue a
+	 * validation item now; for partitioned tables, recurse to process each
+	 * partition.
+	 */
+	if (scanrel->rd_rel->relkind == RELKIND_RELATION)
+	{
+		AlteredTableInfo *tab;
+
+		/* Grab a work queue entry. */
+		tab = ATGetQueueEntry(wqueue, scanrel);
+		Assert(tab->partition_constraint == NULL);
+		tab->partition_constraint = (Expr *) linitial(partConstraint);
+		tab->validate_default = validate_default;
+	}
+	else if (scanrel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
+	{
+		PartitionDesc partdesc = RelationGetPartitionDesc(scanrel, true);
+		int			i;
+
+		for (i = 0; i < partdesc->nparts; i++)
+		{
+			Relation	part_rel;
+			List	   *thisPartConstraint;
+
+			/*
+			 * This is the minimum lock we need to prevent deadlocks.
+			 */
+			part_rel = table_open(partdesc->oids[i], AccessExclusiveLock);
+
+			/*
+			 * Adjust the constraint for scanrel so that it matches this
+			 * partition's attribute numbers.
+			 */
+			thisPartConstraint =
+				map_partition_varattnos(partConstraint, 1,
+										part_rel, scanrel);
+
+			QueuePartitionConstraintValidation(wqueue, part_rel,
+											   thisPartConstraint,
+											   validate_default);
+			table_close(part_rel, NoLock);	/* keep lock till commit */
+		}
+	}
+}
+
+/*
+ * ALTER TABLE <name> ATTACH PARTITION <partition-name> FOR VALUES
+ *
+ * Return the address of the newly attached partition.
+ */
+static ObjectAddress
+ATExecAttachPartition(List **wqueue, Relation rel, PartitionCmd *cmd,
+					  AlterTableUtilityContext *context)
+{
+	Relation	attachrel,
+				catalog;
+	List	   *attachrel_children;
+	List	   *partConstraint;
+	SysScanDesc scan;
+	ScanKeyData skey;
+	AttrNumber	attno;
+	int			natts;
+	TupleDesc	tupleDesc;
+	ObjectAddress address;
+	const char *trigger_name;
+	Oid			defaultPartOid;
+	List	   *partBoundConstraint;
+	ParseState *pstate = make_parsestate(NULL);
+
+	pstate->p_sourcetext = context->queryString;
+
+	/*
+	 * We must lock the default partition if one exists, because attaching a
+	 * new partition will change its partition constraint.
+	 */
+	defaultPartOid =
+		get_default_oid_from_partdesc(RelationGetPartitionDesc(rel, true));
+	if (OidIsValid(defaultPartOid))
+		LockRelationOid(defaultPartOid, AccessExclusiveLock);
+
+	attachrel = table_openrv(cmd->name, AccessExclusiveLock);
+
+	/*
+	 * XXX I think it'd be a good idea to grab locks on all tables referenced
+	 * by FKs at this point also.
+	 */
+
+	/*
+	 * Must be owner of both parent and source table -- parent was checked by
+	 * ATSimplePermissions call in ATPrepCmd
+	 */
+	ATSimplePermissions(AT_AttachPartition, attachrel, ATT_TABLE | ATT_FOREIGN_TABLE);
+
+	/* A partition can only have one parent */
+	if (attachrel->rd_rel->relispartition)
+		ereport(ERROR,
+				(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+				 errmsg("\"%s\" is already a partition",
+						RelationGetRelationName(attachrel))));
+
+	if (OidIsValid(attachrel->rd_rel->reloftype))
+		ereport(ERROR,
+				(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+				 errmsg("cannot attach a typed table as partition")));
+
+	/*
+	 * Table being attached should not already be part of inheritance; either
+	 * as a child table...
+	 */
+	catalog = table_open(InheritsRelationId, AccessShareLock);
+	ScanKeyInit(&skey,
+				Anum_pg_inherits_inhrelid,
+				BTEqualStrategyNumber, F_OIDEQ,
+				ObjectIdGetDatum(RelationGetRelid(attachrel)));
+	scan = systable_beginscan(catalog, InheritsRelidSeqnoIndexId, true,
+							  NULL, 1, &skey);
+	if (HeapTupleIsValid(systable_getnext(scan)))
+		ereport(ERROR,
+				(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+				 errmsg("cannot attach inheritance child as partition")));
+	systable_endscan(scan);
+
+	/* ...or as a parent table (except the case when it is partitioned) */
+	ScanKeyInit(&skey,
+				Anum_pg_inherits_inhparent,
+				BTEqualStrategyNumber, F_OIDEQ,
+				ObjectIdGetDatum(RelationGetRelid(attachrel)));
+	scan = systable_beginscan(catalog, InheritsParentIndexId, true, NULL,
+							  1, &skey);
+	if (HeapTupleIsValid(systable_getnext(scan)) &&
+		attachrel->rd_rel->relkind == RELKIND_RELATION)
+		ereport(ERROR,
+				(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+				 errmsg("cannot attach inheritance parent as partition")));
+	systable_endscan(scan);
+	table_close(catalog, AccessShareLock);
+
+	/*
+	 * Prevent circularity by seeing if rel is a partition of attachrel. (In
+	 * particular, this disallows making a rel a partition of itself.)
+	 *
+	 * We do that by checking if rel is a member of the list of attachrel's
+	 * partitions provided the latter is partitioned at all.  We want to avoid
+	 * having to construct this list again, so we request the strongest lock
+	 * on all partitions.  We need the strongest lock, because we may decide
+	 * to scan them if we find out that the table being attached (or its leaf
+	 * partitions) may contain rows that violate the partition constraint. If
+	 * the table has a constraint that would prevent such rows, which by
+	 * definition is present in all the partitions, we need not scan the
+	 * table, nor its partitions.  But we cannot risk a deadlock by taking a
+	 * weaker lock now and the stronger one only when needed.
+	 */
+	attachrel_children = find_all_inheritors(RelationGetRelid(attachrel),
+											 AccessExclusiveLock, NULL);
+	if (list_member_oid(attachrel_children, RelationGetRelid(rel)))
+		ereport(ERROR,
+				(errcode(ERRCODE_DUPLICATE_TABLE),
+				 errmsg("circular inheritance not allowed"),
+				 errdetail("\"%s\" is already a child of \"%s\".",
+						   RelationGetRelationName(rel),
+						   RelationGetRelationName(attachrel))));
+
+	/* If the parent is permanent, so must be all of its partitions. */
+	if (rel->rd_rel->relpersistence != RELPERSISTENCE_TEMP &&
+		attachrel->rd_rel->relpersistence == RELPERSISTENCE_TEMP)
+		ereport(ERROR,
+				(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+				 errmsg("cannot attach a temporary relation as partition of permanent relation \"%s\"",
+						RelationGetRelationName(rel))));
+
+	/* Temp parent cannot have a partition that is itself not a temp */
+	if (rel->rd_rel->relpersistence == RELPERSISTENCE_TEMP &&
+		attachrel->rd_rel->relpersistence != RELPERSISTENCE_TEMP)
+		ereport(ERROR,
+				(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+				 errmsg("cannot attach a permanent relation as partition of temporary relation \"%s\"",
+						RelationGetRelationName(rel))));
+
+	/* If the parent is temp, it must belong to this session */
+	if (rel->rd_rel->relpersistence == RELPERSISTENCE_TEMP &&
+		!rel->rd_islocaltemp)
+		ereport(ERROR,
+				(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+				 errmsg("cannot attach as partition of temporary relation of another session")));
+
+	/* Ditto for the partition */
+	if (attachrel->rd_rel->relpersistence == RELPERSISTENCE_TEMP &&
+		!attachrel->rd_islocaltemp)
+		ereport(ERROR,
+				(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+				 errmsg("cannot attach temporary relation of another session as partition")));
+
+	/* Check if there are any columns in attachrel that aren't in the parent */
+	tupleDesc = RelationGetDescr(attachrel);
+	natts = tupleDesc->natts;
+	for (attno = 1; attno <= natts; attno++)
+	{
+		Form_pg_attribute attribute = TupleDescAttr(tupleDesc, attno - 1);
+		char	   *attributeName = NameStr(attribute->attname);
+
+		/* Ignore dropped */
+		if (attribute->attisdropped)
+			continue;
+
+		/* Try to find the column in parent (matching on column name) */
+		if (!SearchSysCacheExists2(ATTNAME,
+								   ObjectIdGetDatum(RelationGetRelid(rel)),
+								   CStringGetDatum(attributeName)))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("table \"%s\" contains column \"%s\" not found in parent \"%s\"",
+							RelationGetRelationName(attachrel), attributeName,
+							RelationGetRelationName(rel)),
+					 errdetail("The new partition may contain only the columns present in parent.")));
+	}
+
+	/*
+	 * If child_rel has row-level triggers with transition tables, we
+	 * currently don't allow it to become a partition.  See also prohibitions
+	 * in ATExecAddInherit() and CreateTrigger().
+	 */
+	trigger_name = FindTriggerIncompatibleWithInheritance(attachrel->trigdesc);
+	if (trigger_name != NULL)
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("trigger \"%s\" prevents table \"%s\" from becoming a partition",
+						trigger_name, RelationGetRelationName(attachrel)),
+				 errdetail("ROW triggers with transition tables are not supported on partitions.")));
+
+	/*
+	 * Check that the new partition's bound is valid and does not overlap any
+	 * of existing partitions of the parent - note that it does not return on
+	 * error.
+	 */
+	check_new_partition_bound(RelationGetRelationName(attachrel), rel,
+							  cmd->bound, pstate);
+
+	/* OK to create inheritance.  Rest of the checks performed there */
+	CreateInheritance(attachrel, rel);
+
+	/* Update the pg_class entry. */
+	StorePartitionBound(attachrel, rel, cmd->bound);
+
+	/* Ensure there exists a correct set of indexes in the partition. */
+	AttachPartitionEnsureIndexes(rel, attachrel);
+
+	/* and triggers */
+	CloneRowTriggersToPartition(rel, attachrel);
+
+	/*
+	 * Clone foreign key constraints.  Callee is responsible for setting up
+	 * for phase 3 constraint verification.
+	 */
+	CloneForeignKeyConstraints(wqueue, rel, attachrel);
+
+	/*
+	 * Generate partition constraint from the partition bound specification.
+	 * If the parent itself is a partition, make sure to include its
+	 * constraint as well.
+	 */
+	partBoundConstraint = get_qual_from_partbound(rel, cmd->bound);
+	partConstraint = list_concat(partBoundConstraint,
+								 RelationGetPartitionQual(rel));
+
+	/* Skip validation if there are no constraints to validate. */
+	if (partConstraint)
+	{
+		/*
+		 * Run the partition quals through const-simplification similar to
+		 * check constraints.  We skip canonicalize_qual, though, because
+		 * partition quals should be in canonical form already.
+		 */
+		partConstraint =
+			(List *) eval_const_expressions(NULL,
+											(Node *) partConstraint);
+
+		/* XXX this sure looks wrong */
+		partConstraint = list_make1(make_ands_explicit(partConstraint));
+
+		/*
+		 * Adjust the generated constraint to match this partition's attribute
+		 * numbers.
+		 */
+		partConstraint = map_partition_varattnos(partConstraint, 1, attachrel,
+												 rel);
+
+		/* Validate partition constraints against the table being attached. */
+		QueuePartitionConstraintValidation(wqueue, attachrel, partConstraint,
+										   false);
+	}
+
+	/*
+	 * If we're attaching a partition other than the default partition and a
+	 * default one exists, then that partition's partition constraint changes,
+	 * so add an entry to the work queue to validate it, too.  (We must not do
+	 * this when the partition being attached is the default one; we already
+	 * did it above!)
+	 */
+	if (OidIsValid(defaultPartOid))
+	{
+		Relation	defaultrel;
+		List	   *defPartConstraint;
+
+		Assert(!cmd->bound->is_default);
+
+		/* we already hold a lock on the default partition */
+		defaultrel = table_open(defaultPartOid, NoLock);
+		defPartConstraint =
+			get_proposed_default_constraint(partBoundConstraint);
+
+		/*
+		 * Map the Vars in the constraint expression from rel's attnos to
+		 * defaultrel's.
+		 */
+		defPartConstraint =
+			map_partition_varattnos(defPartConstraint,
+									1, defaultrel, rel);
+		QueuePartitionConstraintValidation(wqueue, defaultrel,
+										   defPartConstraint, true);
+
+		/* keep our lock until commit. */
+		table_close(defaultrel, NoLock);
+	}
+
+	ObjectAddressSet(address, RelationRelationId, RelationGetRelid(attachrel));
+
+	/*
+	 * If the partition we just attached is partitioned itself, invalidate
+	 * relcache for all descendent partitions too to ensure that their
+	 * rd_partcheck expression trees are rebuilt; partitions already locked at
+	 * the beginning of this function.
+	 */
+	if (attachrel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
+	{
+		ListCell   *l;
+
+		foreach(l, attachrel_children)
+		{
+			CacheInvalidateRelcacheByRelid(lfirst_oid(l));
+		}
+	}
+
+	/* keep our lock until commit */
+	table_close(attachrel, NoLock);
+
+	return address;
+}
+
+/*
+ * AttachPartitionEnsureIndexes
+ *		subroutine for ATExecAttachPartition to create/match indexes
+ *
+ * Enforce the indexing rule for partitioned tables during ALTER TABLE / ATTACH
+ * PARTITION: every partition must have an index attached to each index on the
+ * partitioned table.
+ */
+static void
+AttachPartitionEnsureIndexes(Relation rel, Relation attachrel)
+{
+	List	   *idxes;
+	List	   *attachRelIdxs;
+	Relation   *attachrelIdxRels;
+	IndexInfo **attachInfos;
+	int			i;
+	ListCell   *cell;
+	MemoryContext cxt;
+	MemoryContext oldcxt;
+
+	cxt = AllocSetContextCreate(CurrentMemoryContext,
+								"AttachPartitionEnsureIndexes",
+								ALLOCSET_DEFAULT_SIZES);
+	oldcxt = MemoryContextSwitchTo(cxt);
+
+	idxes = RelationGetIndexList(rel);
+	attachRelIdxs = RelationGetIndexList(attachrel);
+	attachrelIdxRels = palloc(sizeof(Relation) * list_length(attachRelIdxs));
+	attachInfos = palloc(sizeof(IndexInfo *) * list_length(attachRelIdxs));
+
+	/* Build arrays of all existing indexes and their IndexInfos */
+	i = 0;
+	foreach(cell, attachRelIdxs)
+	{
+		Oid			cldIdxId = lfirst_oid(cell);
+
+		attachrelIdxRels[i] = index_open(cldIdxId, AccessShareLock);
+		attachInfos[i] = BuildIndexInfo(attachrelIdxRels[i]);
+		i++;
+	}
+
+	/*
+	 * If we're attaching a foreign table, we must fail if any of the indexes
+	 * is a constraint index; otherwise, there's nothing to do here.  Do this
+	 * before starting work, to avoid wasting the effort of building a few
+	 * non-unique indexes before coming across a unique one.
+	 */
+	if (attachrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE)
+	{
+		foreach(cell, idxes)
+		{
+			Oid			idx = lfirst_oid(cell);
+			Relation	idxRel = index_open(idx, AccessShareLock);
+
+			if (idxRel->rd_index->indisunique ||
+				idxRel->rd_index->indisprimary)
+				ereport(ERROR,
+						(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+						 errmsg("cannot attach foreign table \"%s\" as partition of partitioned table \"%s\"",
+								RelationGetRelationName(attachrel),
+								RelationGetRelationName(rel)),
+						 errdetail("Partitioned table \"%s\" contains unique indexes.",
+								   RelationGetRelationName(rel))));
+			index_close(idxRel, AccessShareLock);
+		}
+
+		goto out;
+	}
+
+	/*
+	 * For each index on the partitioned table, find a matching one in the
+	 * partition-to-be; if one is not found, create one.
+	 */
+	foreach(cell, idxes)
+	{
+		Oid			idx = lfirst_oid(cell);
+		Relation	idxRel = index_open(idx, AccessShareLock);
+		IndexInfo  *info;
+		AttrMap    *attmap;
+		bool		found = false;
+		Oid			constraintOid;
+
+		/*
+		 * Ignore indexes in the partitioned table other than partitioned
+		 * indexes.
+		 */
+		if (idxRel->rd_rel->relkind != RELKIND_PARTITIONED_INDEX)
+		{
+			index_close(idxRel, AccessShareLock);
+			continue;
+		}
+
+		/* construct an indexinfo to compare existing indexes against */
+		info = BuildIndexInfo(idxRel);
+		attmap = build_attrmap_by_name(RelationGetDescr(attachrel),
+									   RelationGetDescr(rel));
+		constraintOid = get_relation_idx_constraint_oid(RelationGetRelid(rel), idx);
+
+		/*
+		 * Scan the list of existing indexes in the partition-to-be, and mark
+		 * the first matching, valid, unattached one we find, if any, as
+		 * partition of the parent index.  If we find one, we're done.
+		 */
+		for (i = 0; i < list_length(attachRelIdxs); i++)
+		{
+			Oid			cldIdxId = RelationGetRelid(attachrelIdxRels[i]);
+			Oid			cldConstrOid = InvalidOid;
+
+			/* does this index have a parent?  if so, can't use it */
+			if (attachrelIdxRels[i]->rd_rel->relispartition)
+				continue;
+
+			/* If this index is invalid, can't use it */
+			if (!attachrelIdxRels[i]->rd_index->indisvalid)
+				continue;
+
+			if (CompareIndexInfo(attachInfos[i], info,
+								 attachrelIdxRels[i]->rd_indcollation,
+								 idxRel->rd_indcollation,
+								 attachrelIdxRels[i]->rd_opfamily,
+								 idxRel->rd_opfamily,
+								 attmap))
+			{
+				/*
+				 * If this index is being created in the parent because of a
+				 * constraint, then the child needs to have a constraint also,
+				 * so look for one.  If there is no such constraint, this
+				 * index is no good, so keep looking.
+				 */
+				if (OidIsValid(constraintOid))
+				{
+					cldConstrOid =
+						get_relation_idx_constraint_oid(RelationGetRelid(attachrel),
+														cldIdxId);
+					/* no dice */
+					if (!OidIsValid(cldConstrOid))
+						continue;
+				}
+
+				/* bingo. */
+				IndexSetParentIndex(attachrelIdxRels[i], idx);
+				if (OidIsValid(constraintOid))
+					ConstraintSetParentConstraint(cldConstrOid, constraintOid,
+												  RelationGetRelid(attachrel));
+				found = true;
+
+				CommandCounterIncrement();
+				break;
+			}
+		}
+
+		/*
+		 * If no suitable index was found in the partition-to-be, create one
+		 * now.
+		 */
+		if (!found)
+		{
+			IndexStmt  *stmt;
+			Oid			constraintOid;
+
+			stmt = generateClonedIndexStmt(NULL,
+										   idxRel, attmap,
+										   &constraintOid);
+			DefineIndex(RelationGetRelid(attachrel), stmt, InvalidOid,
+						RelationGetRelid(idxRel),
+						constraintOid,
+						true, false, false, false, false);
+		}
+
+		index_close(idxRel, AccessShareLock);
+	}
+
+out:
+	/* Clean up. */
+	for (i = 0; i < list_length(attachRelIdxs); i++)
+		index_close(attachrelIdxRels[i], AccessShareLock);
+	MemoryContextSwitchTo(oldcxt);
+	MemoryContextDelete(cxt);
+}
+
+/*
+ * CloneRowTriggersToPartition
+ *		subroutine for ATExecAttachPartition/DefineRelation to create row
+ *		triggers on partitions
+ */
+static void
+CloneRowTriggersToPartition(Relation parent, Relation partition)
+{
+	Relation	pg_trigger;
+	ScanKeyData key;
+	SysScanDesc scan;
+	HeapTuple	tuple;
+	MemoryContext perTupCxt;
+
+	ScanKeyInit(&key, Anum_pg_trigger_tgrelid, BTEqualStrategyNumber,
+				F_OIDEQ, ObjectIdGetDatum(RelationGetRelid(parent)));
+	pg_trigger = table_open(TriggerRelationId, RowExclusiveLock);
+	scan = systable_beginscan(pg_trigger, TriggerRelidNameIndexId,
+							  true, NULL, 1, &key);
+
+	perTupCxt = AllocSetContextCreate(CurrentMemoryContext,
+									  "clone trig", ALLOCSET_SMALL_SIZES);
+
+	while (HeapTupleIsValid(tuple = systable_getnext(scan)))
+	{
+		Form_pg_trigger trigForm = (Form_pg_trigger) GETSTRUCT(tuple);
+		CreateTrigStmt *trigStmt;
+		Node	   *qual = NULL;
+		Datum		value;
+		bool		isnull;
+		List	   *cols = NIL;
+		List	   *trigargs = NIL;
+		MemoryContext oldcxt;
+
+		/*
+		 * Ignore statement-level triggers; those are not cloned.
+		 */
+		if (!TRIGGER_FOR_ROW(trigForm->tgtype))
+			continue;
+
+		/*
+		 * Don't clone internal triggers, because the constraint cloning code
+		 * will.
+		 */
+		if (trigForm->tgisinternal)
+			continue;
+
+		/*
+		 * Complain if we find an unexpected trigger type.
+		 */
+		if (!TRIGGER_FOR_BEFORE(trigForm->tgtype) &&
+			!TRIGGER_FOR_AFTER(trigForm->tgtype))
+			elog(ERROR, "unexpected trigger \"%s\" found",
+				 NameStr(trigForm->tgname));
+
+		/* Use short-lived context for CREATE TRIGGER */
+		oldcxt = MemoryContextSwitchTo(perTupCxt);
+
+		/*
+		 * If there is a WHEN clause, generate a 'cooked' version of it that's
+		 * appropriate for the partition.
+		 */
+		value = heap_getattr(tuple, Anum_pg_trigger_tgqual,
+							 RelationGetDescr(pg_trigger), &isnull);
+		if (!isnull)
+		{
+			qual = stringToNode(TextDatumGetCString(value));
+			qual = (Node *) map_partition_varattnos((List *) qual, PRS2_OLD_VARNO,
+													partition, parent);
+			qual = (Node *) map_partition_varattnos((List *) qual, PRS2_NEW_VARNO,
+													partition, parent);
+		}
+
+		/*
+		 * If there is a column list, transform it to a list of column names.
+		 * Note we don't need to map this list in any way ...
+		 */
+		if (trigForm->tgattr.dim1 > 0)
+		{
+			int			i;
+
+			for (i = 0; i < trigForm->tgattr.dim1; i++)
+			{
+				Form_pg_attribute col;
+
+				col = TupleDescAttr(parent->rd_att,
+									trigForm->tgattr.values[i] - 1);
+				cols = lappend(cols,
+							   makeString(pstrdup(NameStr(col->attname))));
+			}
+		}
+
+		/* Reconstruct trigger arguments list. */
+		if (trigForm->tgnargs > 0)
+		{
+			char	   *p;
+
+			value = heap_getattr(tuple, Anum_pg_trigger_tgargs,
+								 RelationGetDescr(pg_trigger), &isnull);
+			if (isnull)
+				elog(ERROR, "tgargs is null for trigger \"%s\" in partition \"%s\"",
+					 NameStr(trigForm->tgname), RelationGetRelationName(partition));
+
+			p = (char *) VARDATA_ANY(DatumGetByteaPP(value));
+
+			for (int i = 0; i < trigForm->tgnargs; i++)
+			{
+				trigargs = lappend(trigargs, makeString(pstrdup(p)));
+				p += strlen(p) + 1;
+			}
+		}
+
+		trigStmt = makeNode(CreateTrigStmt);
+		trigStmt->replace = false;
+		trigStmt->isconstraint = OidIsValid(trigForm->tgconstraint);
+		trigStmt->trigname = NameStr(trigForm->tgname);
+		trigStmt->relation = NULL;
+		trigStmt->funcname = NULL;	/* passed separately */
+		trigStmt->args = trigargs;
+		trigStmt->row = true;
+		trigStmt->timing = trigForm->tgtype & TRIGGER_TYPE_TIMING_MASK;
+		trigStmt->events = trigForm->tgtype & TRIGGER_TYPE_EVENT_MASK;
+		trigStmt->columns = cols;
+		trigStmt->whenClause = NULL;	/* passed separately */
+		trigStmt->transitionRels = NIL; /* not supported at present */
+		trigStmt->deferrable = trigForm->tgdeferrable;
+		trigStmt->initdeferred = trigForm->tginitdeferred;
+		trigStmt->constrrel = NULL; /* passed separately */
+
+		CreateTriggerFiringOn(trigStmt, NULL, RelationGetRelid(partition),
+							  trigForm->tgconstrrelid, InvalidOid, InvalidOid,
+							  trigForm->tgfoid, trigForm->oid, qual,
+							  false, true, trigForm->tgenabled);
+
+		MemoryContextSwitchTo(oldcxt);
+		MemoryContextReset(perTupCxt);
+	}
+
+	MemoryContextDelete(perTupCxt);
+
+	systable_endscan(scan);
+	table_close(pg_trigger, RowExclusiveLock);
+}
+
+/*
+ * ALTER TABLE DETACH PARTITION
+ *
+ * Return the address of the relation that is no longer a partition of rel.
+ *
+ * If concurrent mode is requested, we run in two transactions.  A side-
+ * effect is that this command cannot run in a multi-part ALTER TABLE.
+ * Currently, that's enforced by the grammar.
+ *
+ * The strategy for concurrency is to first modify the partition's
+ * pg_inherit catalog row to make it visible to everyone that the
+ * partition is detached, lock the partition against writes, and commit
+ * the transaction; anyone who requests the partition descriptor from
+ * that point onwards has to ignore such a partition.  In a second
+ * transaction, we wait until all transactions that could have seen the
+ * partition as attached are gone, then we remove the rest of partition
+ * metadata (pg_inherits and pg_class.relpartbounds).
+ */
+static ObjectAddress
+ATExecDetachPartition(List **wqueue, AlteredTableInfo *tab, Relation rel,
+					  RangeVar *name, bool concurrent)
+{
+	Relation	partRel;
+	ObjectAddress address;
+	Oid			defaultPartOid;
+
+	/*
+	 * We must lock the default partition, because detaching this partition
+	 * will change its partition constraint.
+	 */
+	defaultPartOid =
+		get_default_oid_from_partdesc(RelationGetPartitionDesc(rel, true));
+	if (OidIsValid(defaultPartOid))
+	{
+		/*
+		 * Concurrent detaching when a default partition exists is not
+		 * supported. The main problem is that the default partition
+		 * constraint would change.  And there's a definitional problem: what
+		 * should happen to the tuples that are being inserted that belong to
+		 * the partition being detached?  Putting them on the partition being
+		 * detached would be wrong, since they'd become "lost" after the
+		 * detaching completes but we cannot put them in the default partition
+		 * either until we alter its partition constraint.
+		 *
+		 * I think we could solve this problem if we effected the constraint
+		 * change before committing the first transaction.  But the lock would
+		 * have to remain AEL and it would cause concurrent query planning to
+		 * be blocked, so changing it that way would be even worse.
+		 */
+		if (concurrent)
+			ereport(ERROR,
+					(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+					 errmsg("cannot detach partitions concurrently when a default partition exists")));
+		LockRelationOid(defaultPartOid, AccessExclusiveLock);
+	}
+
+	/*
+	 * In concurrent mode, the partition is locked with share-update-exclusive
+	 * in the first transaction.  This allows concurrent transactions to be
+	 * doing DML to the partition.
+	 */
+	partRel = table_openrv(name, concurrent ? ShareUpdateExclusiveLock :
+						   AccessExclusiveLock);
+
+	/*
+	 * Check inheritance conditions and either delete the pg_inherits row (in
+	 * non-concurrent mode) or just set the inhdetachpending flag.
+	 */
+	if (!concurrent)
+		RemoveInheritance(partRel, rel, false);
+	else
+		MarkInheritDetached(partRel, rel);
+
+	/*
+	 * Ensure that foreign keys still hold after this detach.  This keeps
+	 * locks on the referencing tables, which prevents concurrent transactions
+	 * from adding rows that we wouldn't see.  For this to work in concurrent
+	 * mode, it is critical that the partition appears as no longer attached
+	 * for the RI queries as soon as the first transaction commits.
+	 */
+	ATDetachCheckNoForeignKeyRefs(partRel);
+
+	/*
+	 * Concurrent mode has to work harder; first we add a new constraint to
+	 * the partition that matches the partition constraint.  Then we close our
+	 * existing transaction, and in a new one wait for all processes to catch
+	 * up on the catalog updates we've done so far; at that point we can
+	 * complete the operation.
+	 */
+	if (concurrent)
+	{
+		Oid			partrelid,
+					parentrelid;
+		LOCKTAG		tag;
+		char	   *parentrelname;
+		char	   *partrelname;
+
+		/*
+		 * Add a new constraint to the partition being detached, which
+		 * supplants the partition constraint (unless there is one already).
+		 */
+		DetachAddConstraintIfNeeded(wqueue, partRel);
+
+		/*
+		 * We're almost done now; the only traces that remain are the
+		 * pg_inherits tuple and the partition's relpartbounds.  Before we can
+		 * remove those, we need to wait until all transactions that know that
+		 * this is a partition are gone.
+		 */
+
+		/*
+		 * Remember relation OIDs to re-acquire them later; and relation names
+		 * too, for error messages if something is dropped in between.
+		 */
+		partrelid = RelationGetRelid(partRel);
+		parentrelid = RelationGetRelid(rel);
+		parentrelname = MemoryContextStrdup(PortalContext,
+											RelationGetRelationName(rel));
+		partrelname = MemoryContextStrdup(PortalContext,
+										  RelationGetRelationName(partRel));
+
+		/* Invalidate relcache entries for the parent -- must be before close */
+		CacheInvalidateRelcache(rel);
+
+		table_close(partRel, NoLock);
+		table_close(rel, NoLock);
+		tab->rel = NULL;
+
+		/* Make updated catalog entry visible */
+		PopActiveSnapshot();
+		CommitTransactionCommand();
+
+		StartTransactionCommand();
+
+		/*
+		 * Now wait.  This ensures that all queries that were planned
+		 * including the partition are finished before we remove the rest of
+		 * catalog entries.  We don't need or indeed want to acquire this
+		 * lock, though -- that would block later queries.
+		 *
+		 * We don't need to concern ourselves with waiting for a lock on the
+		 * partition itself, since we will acquire AccessExclusiveLock below.
+		 */
+		SET_LOCKTAG_RELATION(tag, MyDatabaseId, parentrelid);
+		WaitForLockersMultiple(list_make1(&tag), AccessExclusiveLock, false);
+
+		/*
+		 * Now acquire locks in both relations again.  Note they may have been
+		 * removed in the meantime, so care is required.
+		 */
+		rel = try_relation_open(parentrelid, ShareUpdateExclusiveLock);
+		partRel = try_relation_open(partrelid, AccessExclusiveLock);
+
+		/* If the relations aren't there, something bad happened; bail out */
+		if (rel == NULL)
+		{
+			if (partRel != NULL)	/* shouldn't happen */
+				elog(WARNING, "dangling partition \"%s\" remains, can't fix",
+					 partrelname);
+			ereport(ERROR,
+					(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+					 errmsg("partitioned table \"%s\" was removed concurrently",
+							parentrelname)));
+		}
+		if (partRel == NULL)
+			ereport(ERROR,
+					(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+					 errmsg("partition \"%s\" was removed concurrently", partrelname)));
+
+		tab->rel = rel;
+	}
+
+	/* Do the final part of detaching */
+	DetachPartitionFinalize(rel, partRel, concurrent, defaultPartOid);
+
+	ObjectAddressSet(address, RelationRelationId, RelationGetRelid(partRel));
+
+	/* keep our lock until commit */
+	table_close(partRel, NoLock);
+
+	return address;
+}
+
+/*
+ * Second part of ALTER TABLE .. DETACH.
+ *
+ * This is separate so that it can be run independently when the second
+ * transaction of the concurrent algorithm fails (crash or abort).
+ */
+static void
+DetachPartitionFinalize(Relation rel, Relation partRel, bool concurrent,
+						Oid defaultPartOid)
+{
+	Relation	classRel;
+	List	   *fks;
+	ListCell   *cell;
+	List	   *indexes;
+	Datum		new_val[Natts_pg_class];
+	bool		new_null[Natts_pg_class],
+				new_repl[Natts_pg_class];
+	HeapTuple	tuple,
+				newtuple;
+	Relation	trigrel = NULL;
+
+	if (concurrent)
+	{
+		/*
+		 * We can remove the pg_inherits row now. (In the non-concurrent case,
+		 * this was already done).
+		 */
+		RemoveInheritance(partRel, rel, true);
+	}
+
+	/* Drop any triggers that were cloned on creation/attach. */
+	DropClonedTriggersFromPartition(RelationGetRelid(partRel));
+
+	/*
+	 * Detach any foreign keys that are inherited.  This includes creating
+	 * additional action triggers.
+	 */
+	fks = copyObject(RelationGetFKeyList(partRel));
+	if (fks != NIL)
+		trigrel = table_open(TriggerRelationId, RowExclusiveLock);
+	foreach(cell, fks)
+	{
+		ForeignKeyCacheInfo *fk = lfirst(cell);
+		HeapTuple	contup;
+		Form_pg_constraint conform;
+		Constraint *fkconstraint;
+		Oid			insertTriggerOid,
+					updateTriggerOid;
+
+		contup = SearchSysCache1(CONSTROID, ObjectIdGetDatum(fk->conoid));
+		if (!HeapTupleIsValid(contup))
+			elog(ERROR, "cache lookup failed for constraint %u", fk->conoid);
+		conform = (Form_pg_constraint) GETSTRUCT(contup);
+
+		/* consider only the inherited foreign keys */
+		if (conform->contype != CONSTRAINT_FOREIGN ||
+			!OidIsValid(conform->conparentid))
+		{
+			ReleaseSysCache(contup);
+			continue;
+		}
+
+		/* unset conparentid and adjust conislocal, coninhcount, etc. */
+		ConstraintSetParentConstraint(fk->conoid, InvalidOid, InvalidOid);
+
+		/*
+		 * Also, look up the partition's "check" triggers corresponding to the
+		 * constraint being detached and detach them from the parent triggers.
+		 */
+		GetForeignKeyCheckTriggers(trigrel,
+								   fk->conoid, fk->confrelid, fk->conrelid,
+								   &insertTriggerOid, &updateTriggerOid);
+		Assert(OidIsValid(insertTriggerOid));
+		TriggerSetParentTrigger(trigrel, insertTriggerOid, InvalidOid,
+								RelationGetRelid(partRel));
+		Assert(OidIsValid(updateTriggerOid));
+		TriggerSetParentTrigger(trigrel, updateTriggerOid, InvalidOid,
+								RelationGetRelid(partRel));
+
+		/*
+		 * Make the action triggers on the referenced relation.  When this was
+		 * a partition the action triggers pointed to the parent rel (they
+		 * still do), but now we need separate ones of our own.
+		 */
+		fkconstraint = makeNode(Constraint);
+		fkconstraint->contype = CONSTRAINT_FOREIGN;
+		fkconstraint->conname = pstrdup(NameStr(conform->conname));
+		fkconstraint->deferrable = conform->condeferrable;
+		fkconstraint->initdeferred = conform->condeferred;
+		fkconstraint->location = -1;
+		fkconstraint->pktable = NULL;
+		fkconstraint->fk_attrs = NIL;
+		fkconstraint->pk_attrs = NIL;
+		fkconstraint->fk_matchtype = conform->confmatchtype;
+		fkconstraint->fk_upd_action = conform->confupdtype;
+		fkconstraint->fk_del_action = conform->confdeltype;
+		fkconstraint->fk_del_set_cols = NIL;
+		fkconstraint->old_conpfeqop = NIL;
+		fkconstraint->old_pktable_oid = InvalidOid;
+		fkconstraint->skip_validation = false;
+		fkconstraint->initially_valid = true;
+
+		createForeignKeyActionTriggers(partRel, conform->confrelid,
+									   fkconstraint, fk->conoid,
+									   conform->conindid,
+									   InvalidOid, InvalidOid,
+									   NULL, NULL);
+
+		ReleaseSysCache(contup);
+	}
+	list_free_deep(fks);
+	if (trigrel)
+		table_close(trigrel, RowExclusiveLock);
+
+	/*
+	 * Any sub-constraints that are in the referenced-side of a larger
+	 * constraint have to be removed.  This partition is no longer part of the
+	 * key space of the constraint.
+	 */
+	foreach(cell, GetParentedForeignKeyRefs(partRel))
+	{
+		Oid			constrOid = lfirst_oid(cell);
+		ObjectAddress constraint;
+
+		ConstraintSetParentConstraint(constrOid, InvalidOid, InvalidOid);
+		deleteDependencyRecordsForClass(ConstraintRelationId,
+										constrOid,
+										ConstraintRelationId,
+										DEPENDENCY_INTERNAL);
+		CommandCounterIncrement();
+
+		ObjectAddressSet(constraint, ConstraintRelationId, constrOid);
+		performDeletion(&constraint, DROP_RESTRICT, 0);
+	}
+
+	/* Now we can detach indexes */
+	indexes = RelationGetIndexList(partRel);
+	foreach(cell, indexes)
+	{
+		Oid			idxid = lfirst_oid(cell);
+		Relation	idx;
+		Oid			constrOid;
+
+		if (!has_superclass(idxid))
+			continue;
+
+		Assert((IndexGetRelation(get_partition_parent(idxid, false), false) ==
+				RelationGetRelid(rel)));
+
+		idx = index_open(idxid, AccessExclusiveLock);
+		IndexSetParentIndex(idx, InvalidOid);
+
+		/* If there's a constraint associated with the index, detach it too */
+		constrOid = get_relation_idx_constraint_oid(RelationGetRelid(partRel),
+													idxid);
+		if (OidIsValid(constrOid))
+			ConstraintSetParentConstraint(constrOid, InvalidOid, InvalidOid);
+
+		index_close(idx, NoLock);
+	}
+
+	/* Update pg_class tuple */
+	classRel = table_open(RelationRelationId, RowExclusiveLock);
+	tuple = SearchSysCacheCopy1(RELOID,
+								ObjectIdGetDatum(RelationGetRelid(partRel)));
+	if (!HeapTupleIsValid(tuple))
+		elog(ERROR, "cache lookup failed for relation %u",
+			 RelationGetRelid(partRel));
+	Assert(((Form_pg_class) GETSTRUCT(tuple))->relispartition);
+
+	/* Clear relpartbound and reset relispartition */
+	memset(new_val, 0, sizeof(new_val));
+	memset(new_null, false, sizeof(new_null));
+	memset(new_repl, false, sizeof(new_repl));
+	new_val[Anum_pg_class_relpartbound - 1] = (Datum) 0;
+	new_null[Anum_pg_class_relpartbound - 1] = true;
+	new_repl[Anum_pg_class_relpartbound - 1] = true;
+	newtuple = heap_modify_tuple(tuple, RelationGetDescr(classRel),
+								 new_val, new_null, new_repl);
+
+	((Form_pg_class) GETSTRUCT(newtuple))->relispartition = false;
+	CatalogTupleUpdate(classRel, &newtuple->t_self, newtuple);
+	heap_freetuple(newtuple);
+	table_close(classRel, RowExclusiveLock);
+
+	if (OidIsValid(defaultPartOid))
+	{
+		/*
+		 * If the relation being detached is the default partition itself,
+		 * remove it from the parent's pg_partitioned_table entry.
+		 *
+		 * If not, we must invalidate default partition's relcache entry, as
+		 * in StorePartitionBound: its partition constraint depends on every
+		 * other partition's partition constraint.
+		 */
+		if (RelationGetRelid(partRel) == defaultPartOid)
+			update_default_partition_oid(RelationGetRelid(rel), InvalidOid);
+		else
+			CacheInvalidateRelcacheByRelid(defaultPartOid);
+	}
+
+	/*
+	 * Invalidate the parent's relcache so that the partition is no longer
+	 * included in its partition descriptor.
+	 */
+	CacheInvalidateRelcache(rel);
+
+	/*
+	 * If the partition we just detached is partitioned itself, invalidate
+	 * relcache for all descendent partitions too to ensure that their
+	 * rd_partcheck expression trees are rebuilt; must lock partitions before
+	 * doing so, using the same lockmode as what partRel has been locked with
+	 * by the caller.
+	 */
+	if (partRel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
+	{
+		List	   *children;
+
+		children = find_all_inheritors(RelationGetRelid(partRel),
+									   AccessExclusiveLock, NULL);
+		foreach(cell, children)
+		{
+			CacheInvalidateRelcacheByRelid(lfirst_oid(cell));
+		}
+	}
+}
+
+/*
+ * ALTER TABLE ... DETACH PARTITION ... FINALIZE
+ *
+ * To use when a DETACH PARTITION command previously did not run to
+ * completion; this completes the detaching process.
+ */
+static ObjectAddress
+ATExecDetachPartitionFinalize(Relation rel, RangeVar *name)
+{
+	Relation	partRel;
+	ObjectAddress address;
+	Snapshot	snap = GetActiveSnapshot();
+
+	partRel = table_openrv(name, AccessExclusiveLock);
+
+	/*
+	 * Wait until existing snapshots are gone.  This is important if the
+	 * second transaction of DETACH PARTITION CONCURRENTLY is canceled: the
+	 * user could immediately run DETACH FINALIZE without actually waiting for
+	 * existing transactions.  We must not complete the detach action until
+	 * all such queries are complete (otherwise we would present them with an
+	 * inconsistent view of catalogs).
+	 */
+	WaitForOlderSnapshots(snap->xmin, false);
+
+	DetachPartitionFinalize(rel, partRel, true, InvalidOid);
+
+	ObjectAddressSet(address, RelationRelationId, RelationGetRelid(partRel));
+
+	table_close(partRel, NoLock);
+
+	return address;
+}
+
+/*
+ * DetachAddConstraintIfNeeded
+ *		Subroutine for ATExecDetachPartition.  Create a constraint that
+ *		takes the place of the partition constraint, but avoid creating
+ *		a dupe if an constraint already exists which implies the needed
+ *		constraint.
+ */
+static void
+DetachAddConstraintIfNeeded(List **wqueue, Relation partRel)
+{
+	List	   *constraintExpr;
+
+	constraintExpr = RelationGetPartitionQual(partRel);
+	constraintExpr = (List *) eval_const_expressions(NULL, (Node *) constraintExpr);
+
+	/*
+	 * Avoid adding a new constraint if the needed constraint is implied by an
+	 * existing constraint
+	 */
+	if (!PartConstraintImpliedByRelConstraint(partRel, constraintExpr))
+	{
+		AlteredTableInfo *tab;
+		Constraint *n;
+
+		tab = ATGetQueueEntry(wqueue, partRel);
+
+		/* Add constraint on partition, equivalent to the partition constraint */
+		n = makeNode(Constraint);
+		n->contype = CONSTR_CHECK;
+		n->conname = NULL;
+		n->location = -1;
+		n->is_no_inherit = false;
+		n->raw_expr = NULL;
+		n->cooked_expr = nodeToString(make_ands_explicit(constraintExpr));
+		n->initially_valid = true;
+		n->skip_validation = true;
+		/* It's a re-add, since it nominally already exists */
+		ATAddCheckConstraint(wqueue, tab, partRel, n,
+							 true, false, true, ShareUpdateExclusiveLock);
+	}
+}
+
+/*
+ * DropClonedTriggersFromPartition
+ *		subroutine for ATExecDetachPartition to remove any triggers that were
+ *		cloned to the partition when it was created-as-partition or attached.
+ *		This undoes what CloneRowTriggersToPartition did.
+ */
+static void
+DropClonedTriggersFromPartition(Oid partitionId)
+{
+	ScanKeyData skey;
+	SysScanDesc scan;
+	HeapTuple	trigtup;
+	Relation	tgrel;
+	ObjectAddresses *objects;
+
+	objects = new_object_addresses();
+
+	/*
+	 * Scan pg_trigger to search for all triggers on this rel.
+	 */
+	ScanKeyInit(&skey, Anum_pg_trigger_tgrelid, BTEqualStrategyNumber,
+				F_OIDEQ, ObjectIdGetDatum(partitionId));
+	tgrel = table_open(TriggerRelationId, RowExclusiveLock);
+	scan = systable_beginscan(tgrel, TriggerRelidNameIndexId,
+							  true, NULL, 1, &skey);
+	while (HeapTupleIsValid(trigtup = systable_getnext(scan)))
+	{
+		Form_pg_trigger pg_trigger = (Form_pg_trigger) GETSTRUCT(trigtup);
+		ObjectAddress trig;
+
+		/* Ignore triggers that weren't cloned */
+		if (!OidIsValid(pg_trigger->tgparentid))
+			continue;
+
+		/*
+		 * Ignore internal triggers that are implementation objects of foreign
+		 * keys, because these will be detached when the foreign keys
+		 * themselves are.
+		 */
+		if (OidIsValid(pg_trigger->tgconstrrelid))
+			continue;
+
+		/*
+		 * This is ugly, but necessary: remove the dependency markings on the
+		 * trigger so that it can be removed.
+		 */
+		deleteDependencyRecordsForClass(TriggerRelationId, pg_trigger->oid,
+										TriggerRelationId,
+										DEPENDENCY_PARTITION_PRI);
+		deleteDependencyRecordsForClass(TriggerRelationId, pg_trigger->oid,
+										RelationRelationId,
+										DEPENDENCY_PARTITION_SEC);
+
+		/* remember this trigger to remove it below */
+		ObjectAddressSet(trig, TriggerRelationId, pg_trigger->oid);
+		add_exact_object_address(&trig, objects);
+	}
+
+	/* make the dependency removal visible to the deletion below */
+	CommandCounterIncrement();
+	performMultipleDeletions(objects, DROP_RESTRICT, PERFORM_DELETION_INTERNAL);
+
+	/* done */
+	free_object_addresses(objects);
+	systable_endscan(scan);
+	table_close(tgrel, RowExclusiveLock);
+}
+
+/*
+ * Before acquiring lock on an index, acquire the same lock on the owning
+ * table.
+ */
+struct AttachIndexCallbackState
+{
+	Oid			partitionOid;
+	Oid			parentTblOid;
+	bool		lockedParentTbl;
+};
+
+static void
+RangeVarCallbackForAttachIndex(const RangeVar *rv, Oid relOid, Oid oldRelOid,
+							   void *arg)
+{
+	struct AttachIndexCallbackState *state;
+	Form_pg_class classform;
+	HeapTuple	tuple;
+
+	state = (struct AttachIndexCallbackState *) arg;
+
+	if (!state->lockedParentTbl)
+	{
+		LockRelationOid(state->parentTblOid, AccessShareLock);
+		state->lockedParentTbl = true;
+	}
+
+	/*
+	 * If we previously locked some other heap, and the name we're looking up
+	 * no longer refers to an index on that relation, release the now-useless
+	 * lock.  XXX maybe we should do *after* we verify whether the index does
+	 * not actually belong to the same relation ...
+	 */
+	if (relOid != oldRelOid && OidIsValid(state->partitionOid))
+	{
+		UnlockRelationOid(state->partitionOid, AccessShareLock);
+		state->partitionOid = InvalidOid;
+	}
+
+	/* Didn't find a relation, so no need for locking or permission checks. */
+	if (!OidIsValid(relOid))
+		return;
+
+	tuple = SearchSysCache1(RELOID, ObjectIdGetDatum(relOid));
+	if (!HeapTupleIsValid(tuple))
+		return;					/* concurrently dropped, so nothing to do */
+	classform = (Form_pg_class) GETSTRUCT(tuple);
+	if (classform->relkind != RELKIND_PARTITIONED_INDEX &&
+		classform->relkind != RELKIND_INDEX)
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
+				 errmsg("\"%s\" is not an index", rv->relname)));
+	ReleaseSysCache(tuple);
+
+	/*
+	 * Since we need only examine the heap's tupledesc, an access share lock
+	 * on it (preventing any DDL) is sufficient.
+	 */
+	state->partitionOid = IndexGetRelation(relOid, false);
+	LockRelationOid(state->partitionOid, AccessShareLock);
+}
+
+/*
+ * ALTER INDEX i1 ATTACH PARTITION i2
+ */
+static ObjectAddress
+ATExecAttachPartitionIdx(List **wqueue, Relation parentIdx, RangeVar *name)
+{
+	Relation	partIdx;
+	Relation	partTbl;
+	Relation	parentTbl;
+	ObjectAddress address;
+	Oid			partIdxId;
+	Oid			currParent;
+	struct AttachIndexCallbackState state;
+
+	/*
+	 * We need to obtain lock on the index 'name' to modify it, but we also
+	 * need to read its owning table's tuple descriptor -- so we need to lock
+	 * both.  To avoid deadlocks, obtain lock on the table before doing so on
+	 * the index.  Furthermore, we need to examine the parent table of the
+	 * partition, so lock that one too.
+	 */
+	state.partitionOid = InvalidOid;
+	state.parentTblOid = parentIdx->rd_index->indrelid;
+	state.lockedParentTbl = false;
+	partIdxId =
+		RangeVarGetRelidExtended(name, AccessExclusiveLock, 0,
+								 RangeVarCallbackForAttachIndex,
+								 (void *) &state);
+	/* Not there? */
+	if (!OidIsValid(partIdxId))
+		ereport(ERROR,
+				(errcode(ERRCODE_UNDEFINED_OBJECT),
+				 errmsg("index \"%s\" does not exist", name->relname)));
+
+	/* no deadlock risk: RangeVarGetRelidExtended already acquired the lock */
+	partIdx = relation_open(partIdxId, AccessExclusiveLock);
+
+	/* we already hold locks on both tables, so this is safe: */
+	parentTbl = relation_open(parentIdx->rd_index->indrelid, AccessShareLock);
+	partTbl = relation_open(partIdx->rd_index->indrelid, NoLock);
+
+	ObjectAddressSet(address, RelationRelationId, RelationGetRelid(partIdx));
+
+	/* Silently do nothing if already in the right state */
+	currParent = partIdx->rd_rel->relispartition ?
+		get_partition_parent(partIdxId, false) : InvalidOid;
+	if (currParent != RelationGetRelid(parentIdx))
+	{
+		IndexInfo  *childInfo;
+		IndexInfo  *parentInfo;
+		AttrMap    *attmap;
+		bool		found;
+		int			i;
+		PartitionDesc partDesc;
+		Oid			constraintOid,
+					cldConstrId = InvalidOid;
+
+		/*
+		 * If this partition already has an index attached, refuse the
+		 * operation.
+		 */
+		refuseDupeIndexAttach(parentIdx, partIdx, partTbl);
+
+		if (OidIsValid(currParent))
+			ereport(ERROR,
+					(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+					 errmsg("cannot attach index \"%s\" as a partition of index \"%s\"",
+							RelationGetRelationName(partIdx),
+							RelationGetRelationName(parentIdx)),
+					 errdetail("Index \"%s\" is already attached to another index.",
+							   RelationGetRelationName(partIdx))));
+
+		/* Make sure it indexes a partition of the other index's table */
+		partDesc = RelationGetPartitionDesc(parentTbl, true);
+		found = false;
+		for (i = 0; i < partDesc->nparts; i++)
+		{
+			if (partDesc->oids[i] == state.partitionOid)
+			{
+				found = true;
+				break;
+			}
+		}
+		if (!found)
+			ereport(ERROR,
+					(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+					 errmsg("cannot attach index \"%s\" as a partition of index \"%s\"",
+							RelationGetRelationName(partIdx),
+							RelationGetRelationName(parentIdx)),
+					 errdetail("Index \"%s\" is not an index on any partition of table \"%s\".",
+							   RelationGetRelationName(partIdx),
+							   RelationGetRelationName(parentTbl))));
+
+		/* Ensure the indexes are compatible */
+		childInfo = BuildIndexInfo(partIdx);
+		parentInfo = BuildIndexInfo(parentIdx);
+		attmap = build_attrmap_by_name(RelationGetDescr(partTbl),
+									   RelationGetDescr(parentTbl));
+		if (!CompareIndexInfo(childInfo, parentInfo,
+							  partIdx->rd_indcollation,
+							  parentIdx->rd_indcollation,
+							  partIdx->rd_opfamily,
+							  parentIdx->rd_opfamily,
+							  attmap))
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
+					 errmsg("cannot attach index \"%s\" as a partition of index \"%s\"",
+							RelationGetRelationName(partIdx),
+							RelationGetRelationName(parentIdx)),
+					 errdetail("The index definitions do not match.")));
+
+		/*
+		 * If there is a constraint in the parent, make sure there is one in
+		 * the child too.
+		 */
+		constraintOid = get_relation_idx_constraint_oid(RelationGetRelid(parentTbl),
+														RelationGetRelid(parentIdx));
+
+		if (OidIsValid(constraintOid))
+		{
+			cldConstrId = get_relation_idx_constraint_oid(RelationGetRelid(partTbl),
+														  partIdxId);
+			if (!OidIsValid(cldConstrId))
+				ereport(ERROR,
+						(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
+						 errmsg("cannot attach index \"%s\" as a partition of index \"%s\"",
+								RelationGetRelationName(partIdx),
+								RelationGetRelationName(parentIdx)),
+						 errdetail("The index \"%s\" belongs to a constraint in table \"%s\" but no constraint exists for index \"%s\".",
+								   RelationGetRelationName(parentIdx),
+								   RelationGetRelationName(parentTbl),
+								   RelationGetRelationName(partIdx))));
+		}
+
+		/* All good -- do it */
+		IndexSetParentIndex(partIdx, RelationGetRelid(parentIdx));
+		if (OidIsValid(constraintOid))
+			ConstraintSetParentConstraint(cldConstrId, constraintOid,
+										  RelationGetRelid(partTbl));
+
+		free_attrmap(attmap);
+
+		validatePartitionedIndex(parentIdx, parentTbl);
+	}
+
+	relation_close(parentTbl, AccessShareLock);
+	/* keep these locks till commit */
+	relation_close(partTbl, NoLock);
+	relation_close(partIdx, NoLock);
+
+	return address;
+}
+
+/*
+ * Verify whether the given partition already contains an index attached
+ * to the given partitioned index.  If so, raise an error.
+ */
+static void
+refuseDupeIndexAttach(Relation parentIdx, Relation partIdx, Relation partitionTbl)
+{
+	Oid			existingIdx;
+
+	existingIdx = index_get_partition(partitionTbl,
+									  RelationGetRelid(parentIdx));
+	if (OidIsValid(existingIdx))
+		ereport(ERROR,
+				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+				 errmsg("cannot attach index \"%s\" as a partition of index \"%s\"",
+						RelationGetRelationName(partIdx),
+						RelationGetRelationName(parentIdx)),
+				 errdetail("Another index is already attached for partition \"%s\".",
+						   RelationGetRelationName(partitionTbl))));
+}
+
+/*
+ * Verify whether the set of attached partition indexes to a parent index on
+ * a partitioned table is complete.  If it is, mark the parent index valid.
+ *
+ * This should be called each time a partition index is attached.
+ */
+static void
+validatePartitionedIndex(Relation partedIdx, Relation partedTbl)
+{
+	Relation	inheritsRel;
+	SysScanDesc scan;
+	ScanKeyData key;
+	int			tuples = 0;
+	HeapTuple	inhTup;
+	bool		updated = false;
+
+	Assert(partedIdx->rd_rel->relkind == RELKIND_PARTITIONED_INDEX);
+
+	/*
+	 * Scan pg_inherits for this parent index.  Count each valid index we find
+	 * (verifying the pg_index entry for each), and if we reach the total
+	 * amount we expect, we can mark this parent index as valid.
+	 */
+	inheritsRel = table_open(InheritsRelationId, AccessShareLock);
+	ScanKeyInit(&key, Anum_pg_inherits_inhparent,
+				BTEqualStrategyNumber, F_OIDEQ,
+				ObjectIdGetDatum(RelationGetRelid(partedIdx)));
+	scan = systable_beginscan(inheritsRel, InheritsParentIndexId, true,
+							  NULL, 1, &key);
+	while ((inhTup = systable_getnext(scan)) != NULL)
+	{
+		Form_pg_inherits inhForm = (Form_pg_inherits) GETSTRUCT(inhTup);
+		HeapTuple	indTup;
+		Form_pg_index indexForm;
+
+		indTup = SearchSysCache1(INDEXRELID,
+								 ObjectIdGetDatum(inhForm->inhrelid));
+		if (!HeapTupleIsValid(indTup))
+			elog(ERROR, "cache lookup failed for index %u", inhForm->inhrelid);
+		indexForm = (Form_pg_index) GETSTRUCT(indTup);
+		if (indexForm->indisvalid)
+			tuples += 1;
+		ReleaseSysCache(indTup);
+	}
+
+	/* Done with pg_inherits */
+	systable_endscan(scan);
+	table_close(inheritsRel, AccessShareLock);
+
+	/*
+	 * If we found as many inherited indexes as the partitioned table has
+	 * partitions, we're good; update pg_index to set indisvalid.
+	 */
+	if (tuples == RelationGetPartitionDesc(partedTbl, true)->nparts)
+	{
+		Relation	idxRel;
+		HeapTuple	indTup;
+		Form_pg_index indexForm;
+
+		idxRel = table_open(IndexRelationId, RowExclusiveLock);
+		indTup = SearchSysCacheCopy1(INDEXRELID,
+									 ObjectIdGetDatum(RelationGetRelid(partedIdx)));
+		if (!HeapTupleIsValid(indTup))
+			elog(ERROR, "cache lookup failed for index %u",
+				 RelationGetRelid(partedIdx));
+		indexForm = (Form_pg_index) GETSTRUCT(indTup);
+
+		indexForm->indisvalid = true;
+		updated = true;
+
+		CatalogTupleUpdate(idxRel, &indTup->t_self, indTup);
+
+		table_close(idxRel, RowExclusiveLock);
+		heap_freetuple(indTup);
+	}
+
+	/*
+	 * If this index is in turn a partition of a larger index, validating it
+	 * might cause the parent to become valid also.  Try that.
+	 */
+	if (updated && partedIdx->rd_rel->relispartition)
+	{
+		Oid			parentIdxId,
+					parentTblId;
+		Relation	parentIdx,
+					parentTbl;
+
+		/* make sure we see the validation we just did */
+		CommandCounterIncrement();
+
+		parentIdxId = get_partition_parent(RelationGetRelid(partedIdx), false);
+		parentTblId = get_partition_parent(RelationGetRelid(partedTbl), false);
+		parentIdx = relation_open(parentIdxId, AccessExclusiveLock);
+		parentTbl = relation_open(parentTblId, AccessExclusiveLock);
+		Assert(!parentIdx->rd_index->indisvalid);
+
+		validatePartitionedIndex(parentIdx, parentTbl);
+
+		relation_close(parentIdx, AccessExclusiveLock);
+		relation_close(parentTbl, AccessExclusiveLock);
+	}
+}
+
+/*
+ * Return an OID list of constraints that reference the given relation
+ * that are marked as having a parent constraints.
+ */
+static List *
+GetParentedForeignKeyRefs(Relation partition)
+{
+	Relation	pg_constraint;
+	HeapTuple	tuple;
+	SysScanDesc scan;
+	ScanKeyData key[2];
+	List	   *constraints = NIL;
+
+	/*
+	 * If no indexes, or no columns are referenceable by FKs, we can avoid the
+	 * scan.
+	 */
+	if (RelationGetIndexList(partition) == NIL ||
+		bms_is_empty(RelationGetIndexAttrBitmap(partition,
+												INDEX_ATTR_BITMAP_KEY)))
+		return NIL;
+
+	/* Search for constraints referencing this table */
+	pg_constraint = table_open(ConstraintRelationId, AccessShareLock);
+	ScanKeyInit(&key[0],
+				Anum_pg_constraint_confrelid, BTEqualStrategyNumber,
+				F_OIDEQ, ObjectIdGetDatum(RelationGetRelid(partition)));
+	ScanKeyInit(&key[1],
+				Anum_pg_constraint_contype, BTEqualStrategyNumber,
+				F_CHAREQ, CharGetDatum(CONSTRAINT_FOREIGN));
+
+	/* XXX This is a seqscan, as we don't have a usable index */
+	scan = systable_beginscan(pg_constraint, InvalidOid, true, NULL, 2, key);
+	while ((tuple = systable_getnext(scan)) != NULL)
+	{
+		Form_pg_constraint constrForm = (Form_pg_constraint) GETSTRUCT(tuple);
+
+		/*
+		 * We only need to process constraints that are part of larger ones.
+		 */
+		if (!OidIsValid(constrForm->conparentid))
+			continue;
+
+		constraints = lappend_oid(constraints, constrForm->oid);
+	}
+
+	systable_endscan(scan);
+	table_close(pg_constraint, AccessShareLock);
+
+	return constraints;
+}
+
+/*
+ * During DETACH PARTITION, verify that any foreign keys pointing to the
+ * partitioned table would not become invalid.  An error is raised if any
+ * referenced values exist.
+ */
+static void
+ATDetachCheckNoForeignKeyRefs(Relation partition)
+{
+	List	   *constraints;
+	ListCell   *cell;
+
+	constraints = GetParentedForeignKeyRefs(partition);
+
+	foreach(cell, constraints)
+	{
+		Oid			constrOid = lfirst_oid(cell);
+		HeapTuple	tuple;
+		Form_pg_constraint constrForm;
+		Relation	rel;
+		Trigger		trig;
+
+		tuple = SearchSysCache1(CONSTROID, ObjectIdGetDatum(constrOid));
+		if (!HeapTupleIsValid(tuple))
+			elog(ERROR, "cache lookup failed for constraint %u", constrOid);
+		constrForm = (Form_pg_constraint) GETSTRUCT(tuple);
+
+		Assert(OidIsValid(constrForm->conparentid));
+		Assert(constrForm->confrelid == RelationGetRelid(partition));
+
+		/* prevent data changes into the referencing table until commit */
+		rel = table_open(constrForm->conrelid, ShareLock);
+
+		MemSet(&trig, 0, sizeof(trig));
+		trig.tgoid = InvalidOid;
+		trig.tgname = NameStr(constrForm->conname);
+		trig.tgenabled = TRIGGER_FIRES_ON_ORIGIN;
+		trig.tgisinternal = true;
+		trig.tgconstrrelid = RelationGetRelid(partition);
+		trig.tgconstrindid = constrForm->conindid;
+		trig.tgconstraint = constrForm->oid;
+		trig.tgdeferrable = false;
+		trig.tginitdeferred = false;
+		/* we needn't fill in remaining fields */
+
+		RI_PartitionRemove_Check(&trig, rel, partition);
+
+		ReleaseSysCache(tuple);
+
+		table_close(rel, NoLock);
+	}
+}
+
+/*
+ * resolve column compression specification to compression method.
+ */
+static char
+GetAttributeCompression(Oid atttypid, char *compression)
+{
+	char		cmethod;
+
+	if (compression == NULL || strcmp(compression, "default") == 0)
+		return InvalidCompressionMethod;
+
+	/*
+	 * To specify a nondefault method, the column data type must be toastable.
+	 * Note this says nothing about whether the column's attstorage setting
+	 * permits compression; we intentionally allow attstorage and
+	 * attcompression to be independent.  But with a non-toastable type,
+	 * attstorage could not be set to a value that would permit compression.
+	 *
+	 * We don't actually need to enforce this, since nothing bad would happen
+	 * if attcompression were non-default; it would never be consulted.  But
+	 * it seems more user-friendly to complain about a certainly-useless
+	 * attempt to set the property.
+	 */
+	if (!TypeIsToastable(atttypid))
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("column data type %s does not support compression",
+						format_type_be(atttypid))));
+
+	cmethod = CompressionNameToMethod(compression);
+	if (!CompressionMethodIsValid(cmethod))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("invalid compression method \"%s\"", compression)));
+
+	return cmethod;
+}