Adding upstream version 14.5.upstream/14.5upstream

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

1 files changed, 4169 insertions, 0 deletions

diff --git a/src/backend/rewrite/rewriteHandler.c b/src/backend/rewrite/rewriteHandler.c
new file mode 100644
index 0000000..9521e81
--- /dev/null
+++ b/src/backend/rewrite/rewriteHandler.c
@@ -0,0 +1,4169 @@
+/*-------------------------------------------------------------------------
+ *
+ * rewriteHandler.c
+ *		Primary module of query rewriter.
+ *
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * IDENTIFICATION
+ *	  src/backend/rewrite/rewriteHandler.c
+ *
+ * NOTES
+ *	  Some of the terms used in this file are of historic nature: "retrieve"
+ *	  was the PostQUEL keyword for what today is SELECT. "RIR" stands for
+ *	  "Retrieve-Instead-Retrieve", that is an ON SELECT DO INSTEAD SELECT rule
+ *	  (which has to be unconditional and where only one rule can exist on each
+ *	  relation).
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "access/relation.h"
+#include "access/sysattr.h"
+#include "access/table.h"
+#include "catalog/dependency.h"
+#include "catalog/pg_type.h"
+#include "commands/trigger.h"
+#include "foreign/fdwapi.h"
+#include "miscadmin.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "optimizer/optimizer.h"
+#include "parser/analyze.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_relation.h"
+#include "parser/parsetree.h"
+#include "rewrite/rewriteDefine.h"
+#include "rewrite/rewriteHandler.h"
+#include "rewrite/rewriteManip.h"
+#include "rewrite/rewriteSearchCycle.h"
+#include "rewrite/rowsecurity.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+#include "utils/rel.h"
+
+
+/* We use a list of these to detect recursion in RewriteQuery */
+typedef struct rewrite_event
+{
+	Oid			relation;		/* OID of relation having rules */
+	CmdType		event;			/* type of rule being fired */
+} rewrite_event;
+
+typedef struct acquireLocksOnSubLinks_context
+{
+	bool		for_execute;	/* AcquireRewriteLocks' forExecute param */
+} acquireLocksOnSubLinks_context;
+
+static bool acquireLocksOnSubLinks(Node *node,
+								   acquireLocksOnSubLinks_context *context);
+static Query *rewriteRuleAction(Query *parsetree,
+								Query *rule_action,
+								Node *rule_qual,
+								int rt_index,
+								CmdType event,
+								bool *returning_flag);
+static List *adjustJoinTreeList(Query *parsetree, bool removert, int rt_index);
+static List *rewriteTargetListIU(List *targetList,
+								 CmdType commandType,
+								 OverridingKind override,
+								 Relation target_relation,
+								 RangeTblEntry *values_rte,
+								 int values_rte_index,
+								 Bitmapset **unused_values_attrnos);
+static TargetEntry *process_matched_tle(TargetEntry *src_tle,
+										TargetEntry *prior_tle,
+										const char *attrName);
+static Node *get_assignment_input(Node *node);
+static Bitmapset *findDefaultOnlyColumns(RangeTblEntry *rte);
+static bool rewriteValuesRTE(Query *parsetree, RangeTblEntry *rte, int rti,
+							 Relation target_relation, bool force_nulls,
+							 Bitmapset *unused_cols);
+static void markQueryForLocking(Query *qry, Node *jtnode,
+								LockClauseStrength strength, LockWaitPolicy waitPolicy,
+								bool pushedDown);
+static List *matchLocks(CmdType event, RuleLock *rulelocks,
+						int varno, Query *parsetree, bool *hasUpdate);
+static Query *fireRIRrules(Query *parsetree, List *activeRIRs);
+static bool view_has_instead_trigger(Relation view, CmdType event);
+static Bitmapset *adjust_view_column_set(Bitmapset *cols, List *targetlist);
+
+
+/*
+ * AcquireRewriteLocks -
+ *	  Acquire suitable locks on all the relations mentioned in the Query.
+ *	  These locks will ensure that the relation schemas don't change under us
+ *	  while we are rewriting, planning, and executing the query.
+ *
+ * Caution: this may modify the querytree, therefore caller should usually
+ * have done a copyObject() to make a writable copy of the querytree in the
+ * current memory context.
+ *
+ * forExecute indicates that the query is about to be executed.  If so,
+ * we'll acquire the lock modes specified in the RTE rellockmode fields.
+ * If forExecute is false, AccessShareLock is acquired on all relations.
+ * This case is suitable for ruleutils.c, for example, where we only need
+ * schema stability and we don't intend to actually modify any relations.
+ *
+ * forUpdatePushedDown indicates that a pushed-down FOR [KEY] UPDATE/SHARE
+ * applies to the current subquery, requiring all rels to be opened with at
+ * least RowShareLock.  This should always be false at the top of the
+ * recursion.  When it is true, we adjust RTE rellockmode fields to reflect
+ * the higher lock level.  This flag is ignored if forExecute is false.
+ *
+ * A secondary purpose of this routine is to fix up JOIN RTE references to
+ * dropped columns (see details below).  Such RTEs are modified in-place.
+ *
+ * This processing can, and for efficiency's sake should, be skipped when the
+ * querytree has just been built by the parser: parse analysis already got
+ * all the same locks we'd get here, and the parser will have omitted dropped
+ * columns from JOINs to begin with.  But we must do this whenever we are
+ * dealing with a querytree produced earlier than the current command.
+ *
+ * About JOINs and dropped columns: although the parser never includes an
+ * already-dropped column in a JOIN RTE's alias var list, it is possible for
+ * such a list in a stored rule to include references to dropped columns.
+ * (If the column is not explicitly referenced anywhere else in the query,
+ * the dependency mechanism won't consider it used by the rule and so won't
+ * prevent the column drop.)  To support get_rte_attribute_is_dropped(), we
+ * replace join alias vars that reference dropped columns with null pointers.
+ *
+ * (In PostgreSQL 8.0, we did not do this processing but instead had
+ * get_rte_attribute_is_dropped() recurse to detect dropped columns in joins.
+ * That approach had horrible performance unfortunately; in particular
+ * construction of a nested join was O(N^2) in the nesting depth.)
+ */
+void
+AcquireRewriteLocks(Query *parsetree,
+					bool forExecute,
+					bool forUpdatePushedDown)
+{
+	ListCell   *l;
+	int			rt_index;
+	acquireLocksOnSubLinks_context context;
+
+	context.for_execute = forExecute;
+
+	/*
+	 * First, process RTEs of the current query level.
+	 */
+	rt_index = 0;
+	foreach(l, parsetree->rtable)
+	{
+		RangeTblEntry *rte = (RangeTblEntry *) lfirst(l);
+		Relation	rel;
+		LOCKMODE	lockmode;
+		List	   *newaliasvars;
+		Index		curinputvarno;
+		RangeTblEntry *curinputrte;
+		ListCell   *ll;
+
+		++rt_index;
+		switch (rte->rtekind)
+		{
+			case RTE_RELATION:
+
+				/*
+				 * Grab the appropriate lock type for the relation, and do not
+				 * release it until end of transaction.  This protects the
+				 * rewriter, planner, and executor against schema changes
+				 * mid-query.
+				 *
+				 * If forExecute is false, ignore rellockmode and just use
+				 * AccessShareLock.
+				 */
+				if (!forExecute)
+					lockmode = AccessShareLock;
+				else if (forUpdatePushedDown)
+				{
+					/* Upgrade RTE's lock mode to reflect pushed-down lock */
+					if (rte->rellockmode == AccessShareLock)
+						rte->rellockmode = RowShareLock;
+					lockmode = rte->rellockmode;
+				}
+				else
+					lockmode = rte->rellockmode;
+
+				rel = table_open(rte->relid, lockmode);
+
+				/*
+				 * While we have the relation open, update the RTE's relkind,
+				 * just in case it changed since this rule was made.
+				 */
+				rte->relkind = rel->rd_rel->relkind;
+
+				table_close(rel, NoLock);
+				break;
+
+			case RTE_JOIN:
+
+				/*
+				 * Scan the join's alias var list to see if any columns have
+				 * been dropped, and if so replace those Vars with null
+				 * pointers.
+				 *
+				 * Since a join has only two inputs, we can expect to see
+				 * multiple references to the same input RTE; optimize away
+				 * multiple fetches.
+				 */
+				newaliasvars = NIL;
+				curinputvarno = 0;
+				curinputrte = NULL;
+				foreach(ll, rte->joinaliasvars)
+				{
+					Var		   *aliasitem = (Var *) lfirst(ll);
+					Var		   *aliasvar = aliasitem;
+
+					/* Look through any implicit coercion */
+					aliasvar = (Var *) strip_implicit_coercions((Node *) aliasvar);
+
+					/*
+					 * If the list item isn't a simple Var, then it must
+					 * represent a merged column, ie a USING column, and so it
+					 * couldn't possibly be dropped, since it's referenced in
+					 * the join clause.  (Conceivably it could also be a null
+					 * pointer already?  But that's OK too.)
+					 */
+					if (aliasvar && IsA(aliasvar, Var))
+					{
+						/*
+						 * The elements of an alias list have to refer to
+						 * earlier RTEs of the same rtable, because that's the
+						 * order the planner builds things in.  So we already
+						 * processed the referenced RTE, and so it's safe to
+						 * use get_rte_attribute_is_dropped on it. (This might
+						 * not hold after rewriting or planning, but it's OK
+						 * to assume here.)
+						 */
+						Assert(aliasvar->varlevelsup == 0);
+						if (aliasvar->varno != curinputvarno)
+						{
+							curinputvarno = aliasvar->varno;
+							if (curinputvarno >= rt_index)
+								elog(ERROR, "unexpected varno %d in JOIN RTE %d",
+									 curinputvarno, rt_index);
+							curinputrte = rt_fetch(curinputvarno,
+												   parsetree->rtable);
+						}
+						if (get_rte_attribute_is_dropped(curinputrte,
+														 aliasvar->varattno))
+						{
+							/* Replace the join alias item with a NULL */
+							aliasitem = NULL;
+						}
+					}
+					newaliasvars = lappend(newaliasvars, aliasitem);
+				}
+				rte->joinaliasvars = newaliasvars;
+				break;
+
+			case RTE_SUBQUERY:
+
+				/*
+				 * The subquery RTE itself is all right, but we have to
+				 * recurse to process the represented subquery.
+				 */
+				AcquireRewriteLocks(rte->subquery,
+									forExecute,
+									(forUpdatePushedDown ||
+									 get_parse_rowmark(parsetree, rt_index) != NULL));
+				break;
+
+			default:
+				/* ignore other types of RTEs */
+				break;
+		}
+	}
+
+	/* Recurse into subqueries in WITH */
+	foreach(l, parsetree->cteList)
+	{
+		CommonTableExpr *cte = (CommonTableExpr *) lfirst(l);
+
+		AcquireRewriteLocks((Query *) cte->ctequery, forExecute, false);
+	}
+
+	/*
+	 * Recurse into sublink subqueries, too.  But we already did the ones in
+	 * the rtable and cteList.
+	 */
+	if (parsetree->hasSubLinks)
+		query_tree_walker(parsetree, acquireLocksOnSubLinks, &context,
+						  QTW_IGNORE_RC_SUBQUERIES);
+}
+
+/*
+ * Walker to find sublink subqueries for AcquireRewriteLocks
+ */
+static bool
+acquireLocksOnSubLinks(Node *node, acquireLocksOnSubLinks_context *context)
+{
+	if (node == NULL)
+		return false;
+	if (IsA(node, SubLink))
+	{
+		SubLink    *sub = (SubLink *) node;
+
+		/* Do what we came for */
+		AcquireRewriteLocks((Query *) sub->subselect,
+							context->for_execute,
+							false);
+		/* Fall through to process lefthand args of SubLink */
+	}
+
+	/*
+	 * Do NOT recurse into Query nodes, because AcquireRewriteLocks already
+	 * processed subselects of subselects for us.
+	 */
+	return expression_tree_walker(node, acquireLocksOnSubLinks, context);
+}
+
+
+/*
+ * rewriteRuleAction -
+ *	  Rewrite the rule action with appropriate qualifiers (taken from
+ *	  the triggering query).
+ *
+ * Input arguments:
+ *	parsetree - original query
+ *	rule_action - one action (query) of a rule
+ *	rule_qual - WHERE condition of rule, or NULL if unconditional
+ *	rt_index - RT index of result relation in original query
+ *	event - type of rule event
+ * Output arguments:
+ *	*returning_flag - set true if we rewrite RETURNING clause in rule_action
+ *					(must be initialized to false)
+ * Return value:
+ *	rewritten form of rule_action
+ */
+static Query *
+rewriteRuleAction(Query *parsetree,
+				  Query *rule_action,
+				  Node *rule_qual,
+				  int rt_index,
+				  CmdType event,
+				  bool *returning_flag)
+{
+	int			current_varno,
+				new_varno;
+	int			rt_length;
+	Query	   *sub_action;
+	Query	  **sub_action_ptr;
+	acquireLocksOnSubLinks_context context;
+
+	context.for_execute = true;
+
+	/*
+	 * Make modifiable copies of rule action and qual (what we're passed are
+	 * the stored versions in the relcache; don't touch 'em!).
+	 */
+	rule_action = copyObject(rule_action);
+	rule_qual = copyObject(rule_qual);
+
+	/*
+	 * Acquire necessary locks and fix any deleted JOIN RTE entries.
+	 */
+	AcquireRewriteLocks(rule_action, true, false);
+	(void) acquireLocksOnSubLinks(rule_qual, &context);
+
+	current_varno = rt_index;
+	rt_length = list_length(parsetree->rtable);
+	new_varno = PRS2_NEW_VARNO + rt_length;
+
+	/*
+	 * Adjust rule action and qual to offset its varnos, so that we can merge
+	 * its rtable with the main parsetree's rtable.
+	 *
+	 * If the rule action is an INSERT...SELECT, the OLD/NEW rtable entries
+	 * will be in the SELECT part, and we have to modify that rather than the
+	 * top-level INSERT (kluge!).
+	 */
+	sub_action = getInsertSelectQuery(rule_action, &sub_action_ptr);
+
+	OffsetVarNodes((Node *) sub_action, rt_length, 0);
+	OffsetVarNodes(rule_qual, rt_length, 0);
+	/* but references to OLD should point at original rt_index */
+	ChangeVarNodes((Node *) sub_action,
+				   PRS2_OLD_VARNO + rt_length, rt_index, 0);
+	ChangeVarNodes(rule_qual,
+				   PRS2_OLD_VARNO + rt_length, rt_index, 0);
+
+	/*
+	 * Generate expanded rtable consisting of main parsetree's rtable plus
+	 * rule action's rtable; this becomes the complete rtable for the rule
+	 * action.  Some of the entries may be unused after we finish rewriting,
+	 * but we leave them all in place for two reasons:
+	 *
+	 * We'd have a much harder job to adjust the query's varnos if we
+	 * selectively removed RT entries.
+	 *
+	 * If the rule is INSTEAD, then the original query won't be executed at
+	 * all, and so its rtable must be preserved so that the executor will do
+	 * the correct permissions checks on it.
+	 *
+	 * RT entries that are not referenced in the completed jointree will be
+	 * ignored by the planner, so they do not affect query semantics.  But any
+	 * permissions checks specified in them will be applied during executor
+	 * startup (see ExecCheckRTEPerms()).  This allows us to check that the
+	 * caller has, say, insert-permission on a view, when the view is not
+	 * semantically referenced at all in the resulting query.
+	 *
+	 * When a rule is not INSTEAD, the permissions checks done on its copied
+	 * RT entries will be redundant with those done during execution of the
+	 * original query, but we don't bother to treat that case differently.
+	 *
+	 * NOTE: because planner will destructively alter rtable, we must ensure
+	 * that rule action's rtable is separate and shares no substructure with
+	 * the main rtable.  Hence do a deep copy here.
+	 */
+	sub_action->rtable = list_concat(copyObject(parsetree->rtable),
+									 sub_action->rtable);
+
+	/*
+	 * There could have been some SubLinks in parsetree's rtable, in which
+	 * case we'd better mark the sub_action correctly.
+	 */
+	if (parsetree->hasSubLinks && !sub_action->hasSubLinks)
+	{
+		ListCell   *lc;
+
+		foreach(lc, parsetree->rtable)
+		{
+			RangeTblEntry *rte = (RangeTblEntry *) lfirst(lc);
+
+			switch (rte->rtekind)
+			{
+				case RTE_RELATION:
+					sub_action->hasSubLinks =
+						checkExprHasSubLink((Node *) rte->tablesample);
+					break;
+				case RTE_FUNCTION:
+					sub_action->hasSubLinks =
+						checkExprHasSubLink((Node *) rte->functions);
+					break;
+				case RTE_TABLEFUNC:
+					sub_action->hasSubLinks =
+						checkExprHasSubLink((Node *) rte->tablefunc);
+					break;
+				case RTE_VALUES:
+					sub_action->hasSubLinks =
+						checkExprHasSubLink((Node *) rte->values_lists);
+					break;
+				default:
+					/* other RTE types don't contain bare expressions */
+					break;
+			}
+			if (sub_action->hasSubLinks)
+				break;			/* no need to keep scanning rtable */
+		}
+	}
+
+	/*
+	 * Also, we might have absorbed some RTEs with RLS conditions into the
+	 * sub_action.  If so, mark it as hasRowSecurity, whether or not those
+	 * RTEs will be referenced after we finish rewriting.  (Note: currently
+	 * this is a no-op because RLS conditions aren't added till later, but it
+	 * seems like good future-proofing to do this anyway.)
+	 */
+	sub_action->hasRowSecurity |= parsetree->hasRowSecurity;
+
+	/*
+	 * Each rule action's jointree should be the main parsetree's jointree
+	 * plus that rule's jointree, but usually *without* the original rtindex
+	 * that we're replacing (if present, which it won't be for INSERT). Note
+	 * that if the rule action refers to OLD, its jointree will add a
+	 * reference to rt_index.  If the rule action doesn't refer to OLD, but
+	 * either the rule_qual or the user query quals do, then we need to keep
+	 * the original rtindex in the jointree to provide data for the quals.  We
+	 * don't want the original rtindex to be joined twice, however, so avoid
+	 * keeping it if the rule action mentions it.
+	 *
+	 * As above, the action's jointree must not share substructure with the
+	 * main parsetree's.
+	 */
+	if (sub_action->commandType != CMD_UTILITY)
+	{
+		bool		keeporig;
+		List	   *newjointree;
+
+		Assert(sub_action->jointree != NULL);
+		keeporig = (!rangeTableEntry_used((Node *) sub_action->jointree,
+										  rt_index, 0)) &&
+			(rangeTableEntry_used(rule_qual, rt_index, 0) ||
+			 rangeTableEntry_used(parsetree->jointree->quals, rt_index, 0));
+		newjointree = adjustJoinTreeList(parsetree, !keeporig, rt_index);
+		if (newjointree != NIL)
+		{
+			/*
+			 * If sub_action is a setop, manipulating its jointree will do no
+			 * good at all, because the jointree is dummy.  (Perhaps someday
+			 * we could push the joining and quals down to the member
+			 * statements of the setop?)
+			 */
+			if (sub_action->setOperations != NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+						 errmsg("conditional UNION/INTERSECT/EXCEPT statements are not implemented")));
+
+			sub_action->jointree->fromlist =
+				list_concat(newjointree, sub_action->jointree->fromlist);
+
+			/*
+			 * There could have been some SubLinks in newjointree, in which
+			 * case we'd better mark the sub_action correctly.
+			 */
+			if (parsetree->hasSubLinks && !sub_action->hasSubLinks)
+				sub_action->hasSubLinks =
+					checkExprHasSubLink((Node *) newjointree);
+		}
+	}
+
+	/*
+	 * If the original query has any CTEs, copy them into the rule action. But
+	 * we don't need them for a utility action.
+	 */
+	if (parsetree->cteList != NIL && sub_action->commandType != CMD_UTILITY)
+	{
+		ListCell   *lc;
+
+		/*
+		 * Annoying implementation restriction: because CTEs are identified by
+		 * name within a cteList, we can't merge a CTE from the original query
+		 * if it has the same name as any CTE in the rule action.
+		 *
+		 * This could possibly be fixed by using some sort of internally
+		 * generated ID, instead of names, to link CTE RTEs to their CTEs.
+		 * However, decompiling the results would be quite confusing; note the
+		 * merge of hasRecursive flags below, which could change the apparent
+		 * semantics of such redundantly-named CTEs.
+		 */
+		foreach(lc, parsetree->cteList)
+		{
+			CommonTableExpr *cte = (CommonTableExpr *) lfirst(lc);
+			ListCell   *lc2;
+
+			foreach(lc2, sub_action->cteList)
+			{
+				CommonTableExpr *cte2 = (CommonTableExpr *) lfirst(lc2);
+
+				if (strcmp(cte->ctename, cte2->ctename) == 0)
+					ereport(ERROR,
+							(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+							 errmsg("WITH query name \"%s\" appears in both a rule action and the query being rewritten",
+									cte->ctename)));
+			}
+		}
+
+		/* OK, it's safe to combine the CTE lists */
+		sub_action->cteList = list_concat(sub_action->cteList,
+										  copyObject(parsetree->cteList));
+		/* ... and don't forget about the associated flags */
+		sub_action->hasRecursive |= parsetree->hasRecursive;
+		sub_action->hasModifyingCTE |= parsetree->hasModifyingCTE;
+
+		/*
+		 * If rule_action is different from sub_action (i.e., the rule action
+		 * is an INSERT...SELECT), then we might have just added some
+		 * data-modifying CTEs that are not at the top query level.  This is
+		 * disallowed by the parser and we mustn't generate such trees here
+		 * either, so throw an error.
+		 *
+		 * Conceivably such cases could be supported by attaching the original
+		 * query's CTEs to rule_action not sub_action.  But to do that, we'd
+		 * have to increment ctelevelsup in RTEs and SubLinks copied from the
+		 * original query.  For now, it doesn't seem worth the trouble.
+		 */
+		if (sub_action->hasModifyingCTE && rule_action != sub_action)
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("INSERT...SELECT rule actions are not supported for queries having data-modifying statements in WITH")));
+	}
+
+	/*
+	 * Event Qualification forces copying of parsetree and splitting into two
+	 * queries one w/rule_qual, one w/NOT rule_qual. Also add user query qual
+	 * onto rule action
+	 */
+	AddQual(sub_action, rule_qual);
+
+	AddQual(sub_action, parsetree->jointree->quals);
+
+	/*
+	 * Rewrite new.attribute with right hand side of target-list entry for
+	 * appropriate field name in insert/update.
+	 *
+	 * KLUGE ALERT: since ReplaceVarsFromTargetList returns a mutated copy, we
+	 * can't just apply it to sub_action; we have to remember to update the
+	 * sublink inside rule_action, too.
+	 */
+	if ((event == CMD_INSERT || event == CMD_UPDATE) &&
+		sub_action->commandType != CMD_UTILITY)
+	{
+		sub_action = (Query *)
+			ReplaceVarsFromTargetList((Node *) sub_action,
+									  new_varno,
+									  0,
+									  rt_fetch(new_varno, sub_action->rtable),
+									  parsetree->targetList,
+									  (event == CMD_UPDATE) ?
+									  REPLACEVARS_CHANGE_VARNO :
+									  REPLACEVARS_SUBSTITUTE_NULL,
+									  current_varno,
+									  NULL);
+		if (sub_action_ptr)
+			*sub_action_ptr = sub_action;
+		else
+			rule_action = sub_action;
+	}
+
+	/*
+	 * If rule_action has a RETURNING clause, then either throw it away if the
+	 * triggering query has no RETURNING clause, or rewrite it to emit what
+	 * the triggering query's RETURNING clause asks for.  Throw an error if
+	 * more than one rule has a RETURNING clause.
+	 */
+	if (!parsetree->returningList)
+		rule_action->returningList = NIL;
+	else if (rule_action->returningList)
+	{
+		if (*returning_flag)
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("cannot have RETURNING lists in multiple rules")));
+		*returning_flag = true;
+		rule_action->returningList = (List *)
+			ReplaceVarsFromTargetList((Node *) parsetree->returningList,
+									  parsetree->resultRelation,
+									  0,
+									  rt_fetch(parsetree->resultRelation,
+											   parsetree->rtable),
+									  rule_action->returningList,
+									  REPLACEVARS_REPORT_ERROR,
+									  0,
+									  &rule_action->hasSubLinks);
+
+		/*
+		 * There could have been some SubLinks in parsetree's returningList,
+		 * in which case we'd better mark the rule_action correctly.
+		 */
+		if (parsetree->hasSubLinks && !rule_action->hasSubLinks)
+			rule_action->hasSubLinks =
+				checkExprHasSubLink((Node *) rule_action->returningList);
+	}
+
+	return rule_action;
+}
+
+/*
+ * Copy the query's jointree list, and optionally attempt to remove any
+ * occurrence of the given rt_index as a top-level join item (we do not look
+ * for it within join items; this is OK because we are only expecting to find
+ * it as an UPDATE or DELETE target relation, which will be at the top level
+ * of the join).  Returns modified jointree list --- this is a separate copy
+ * sharing no nodes with the original.
+ */
+static List *
+adjustJoinTreeList(Query *parsetree, bool removert, int rt_index)
+{
+	List	   *newjointree = copyObject(parsetree->jointree->fromlist);
+	ListCell   *l;
+
+	if (removert)
+	{
+		foreach(l, newjointree)
+		{
+			RangeTblRef *rtr = lfirst(l);
+
+			if (IsA(rtr, RangeTblRef) &&
+				rtr->rtindex == rt_index)
+			{
+				newjointree = foreach_delete_current(newjointree, l);
+				break;
+			}
+		}
+	}
+	return newjointree;
+}
+
+
+/*
+ * rewriteTargetListIU - rewrite INSERT/UPDATE targetlist into standard form
+ *
+ * This has the following responsibilities:
+ *
+ * 1. For an INSERT, add tlist entries to compute default values for any
+ * attributes that have defaults and are not assigned to in the given tlist.
+ * (We do not insert anything for default-less attributes, however.  The
+ * planner will later insert NULLs for them, but there's no reason to slow
+ * down rewriter processing with extra tlist nodes.)  Also, for both INSERT
+ * and UPDATE, replace explicit DEFAULT specifications with column default
+ * expressions.
+ *
+ * 2. Merge multiple entries for the same target attribute, or declare error
+ * if we can't.  Multiple entries are only allowed for INSERT/UPDATE of
+ * portions of an array or record field, for example
+ *			UPDATE table SET foo[2] = 42, foo[4] = 43;
+ * We can merge such operations into a single assignment op.  Essentially,
+ * the expression we want to produce in this case is like
+ *		foo = array_set_element(array_set_element(foo, 2, 42), 4, 43)
+ *
+ * 3. Sort the tlist into standard order: non-junk fields in order by resno,
+ * then junk fields (these in no particular order).
+ *
+ * We must do items 1 and 2 before firing rewrite rules, else rewritten
+ * references to NEW.foo will produce wrong or incomplete results.  Item 3
+ * is not needed for rewriting, but it is helpful for the planner, and we
+ * can do it essentially for free while handling the other items.
+ *
+ * If values_rte is non-NULL (i.e., we are doing a multi-row INSERT using
+ * values from a VALUES RTE), we populate *unused_values_attrnos with the
+ * attribute numbers of any unused columns from the VALUES RTE.  This can
+ * happen for identity and generated columns whose targetlist entries are
+ * replaced with generated expressions (if INSERT ... OVERRIDING USER VALUE is
+ * used, or all the values to be inserted are DEFAULT).  This information is
+ * required by rewriteValuesRTE() to handle any DEFAULT items in the unused
+ * columns.  The caller must have initialized *unused_values_attrnos to NULL.
+ */
+static List *
+rewriteTargetListIU(List *targetList,
+					CmdType commandType,
+					OverridingKind override,
+					Relation target_relation,
+					RangeTblEntry *values_rte,
+					int values_rte_index,
+					Bitmapset **unused_values_attrnos)
+{
+	TargetEntry **new_tles;
+	List	   *new_tlist = NIL;
+	List	   *junk_tlist = NIL;
+	Form_pg_attribute att_tup;
+	int			attrno,
+				next_junk_attrno,
+				numattrs;
+	ListCell   *temp;
+	Bitmapset  *default_only_cols = NULL;
+
+	/*
+	 * We process the normal (non-junk) attributes by scanning the input tlist
+	 * once and transferring TLEs into an array, then scanning the array to
+	 * build an output tlist.  This avoids O(N^2) behavior for large numbers
+	 * of attributes.
+	 *
+	 * Junk attributes are tossed into a separate list during the same tlist
+	 * scan, then appended to the reconstructed tlist.
+	 */
+	numattrs = RelationGetNumberOfAttributes(target_relation);
+	new_tles = (TargetEntry **) palloc0(numattrs * sizeof(TargetEntry *));
+	next_junk_attrno = numattrs + 1;
+
+	foreach(temp, targetList)
+	{
+		TargetEntry *old_tle = (TargetEntry *) lfirst(temp);
+
+		if (!old_tle->resjunk)
+		{
+			/* Normal attr: stash it into new_tles[] */
+			attrno = old_tle->resno;
+			if (attrno < 1 || attrno > numattrs)
+				elog(ERROR, "bogus resno %d in targetlist", attrno);
+			att_tup = TupleDescAttr(target_relation->rd_att, attrno - 1);
+
+			/* We can (and must) ignore deleted attributes */
+			if (att_tup->attisdropped)
+				continue;
+
+			/* Merge with any prior assignment to same attribute */
+			new_tles[attrno - 1] =
+				process_matched_tle(old_tle,
+									new_tles[attrno - 1],
+									NameStr(att_tup->attname));
+		}
+		else
+		{
+			/*
+			 * Copy all resjunk tlist entries to junk_tlist, and assign them
+			 * resnos above the last real resno.
+			 *
+			 * Typical junk entries include ORDER BY or GROUP BY expressions
+			 * (are these actually possible in an INSERT or UPDATE?), system
+			 * attribute references, etc.
+			 */
+
+			/* Get the resno right, but don't copy unnecessarily */
+			if (old_tle->resno != next_junk_attrno)
+			{
+				old_tle = flatCopyTargetEntry(old_tle);
+				old_tle->resno = next_junk_attrno;
+			}
+			junk_tlist = lappend(junk_tlist, old_tle);
+			next_junk_attrno++;
+		}
+	}
+
+	for (attrno = 1; attrno <= numattrs; attrno++)
+	{
+		TargetEntry *new_tle = new_tles[attrno - 1];
+		bool		apply_default;
+
+		att_tup = TupleDescAttr(target_relation->rd_att, attrno - 1);
+
+		/* We can (and must) ignore deleted attributes */
+		if (att_tup->attisdropped)
+			continue;
+
+		/*
+		 * Handle the two cases where we need to insert a default expression:
+		 * it's an INSERT and there's no tlist entry for the column, or the
+		 * tlist entry is a DEFAULT placeholder node.
+		 */
+		apply_default = ((new_tle == NULL && commandType == CMD_INSERT) ||
+						 (new_tle && new_tle->expr && IsA(new_tle->expr, SetToDefault)));
+
+		if (commandType == CMD_INSERT)
+		{
+			int			values_attrno = 0;
+
+			/* Source attribute number for values that come from a VALUES RTE */
+			if (values_rte && new_tle && IsA(new_tle->expr, Var))
+			{
+				Var		   *var = (Var *) new_tle->expr;
+
+				if (var->varno == values_rte_index)
+					values_attrno = var->varattno;
+			}
+
+			/*
+			 * Can only insert DEFAULT into GENERATED ALWAYS identity columns,
+			 * unless either OVERRIDING USER VALUE or OVERRIDING SYSTEM VALUE
+			 * is specified.
+			 */
+			if (att_tup->attidentity == ATTRIBUTE_IDENTITY_ALWAYS && !apply_default)
+			{
+				if (override == OVERRIDING_USER_VALUE)
+					apply_default = true;
+				else if (override != OVERRIDING_SYSTEM_VALUE)
+				{
+					/*
+					 * If this column's values come from a VALUES RTE, test
+					 * whether it contains only SetToDefault items.  Since the
+					 * VALUES list might be quite large, we arrange to only
+					 * scan it once.
+					 */
+					if (values_attrno != 0)
+					{
+						if (default_only_cols == NULL)
+							default_only_cols = findDefaultOnlyColumns(values_rte);
+
+						if (bms_is_member(values_attrno, default_only_cols))
+							apply_default = true;
+					}
+
+					if (!apply_default)
+						ereport(ERROR,
+								(errcode(ERRCODE_GENERATED_ALWAYS),
+								 errmsg("cannot insert a non-DEFAULT value into column \"%s\"",
+										NameStr(att_tup->attname)),
+								 errdetail("Column \"%s\" is an identity column defined as GENERATED ALWAYS.",
+										   NameStr(att_tup->attname)),
+								 errhint("Use OVERRIDING SYSTEM VALUE to override.")));
+				}
+			}
+
+			/*
+			 * Although inserting into a GENERATED BY DEFAULT identity column
+			 * is allowed, apply the default if OVERRIDING USER VALUE is
+			 * specified.
+			 */
+			if (att_tup->attidentity == ATTRIBUTE_IDENTITY_BY_DEFAULT &&
+				override == OVERRIDING_USER_VALUE)
+				apply_default = true;
+
+			/*
+			 * Can only insert DEFAULT into generated columns, regardless of
+			 * any OVERRIDING clauses.
+			 */
+			if (att_tup->attgenerated && !apply_default)
+			{
+				/*
+				 * If this column's values come from a VALUES RTE, test
+				 * whether it contains only SetToDefault items, as above.
+				 */
+				if (values_attrno != 0)
+				{
+					if (default_only_cols == NULL)
+						default_only_cols = findDefaultOnlyColumns(values_rte);
+
+					if (bms_is_member(values_attrno, default_only_cols))
+						apply_default = true;
+				}
+
+				if (!apply_default)
+					ereport(ERROR,
+							(errcode(ERRCODE_GENERATED_ALWAYS),
+							 errmsg("cannot insert a non-DEFAULT value into column \"%s\"",
+									NameStr(att_tup->attname)),
+							 errdetail("Column \"%s\" is a generated column.",
+									   NameStr(att_tup->attname))));
+			}
+
+			/*
+			 * For an INSERT from a VALUES RTE, return the attribute numbers
+			 * of any VALUES columns that will no longer be used (due to the
+			 * targetlist entry being replaced by a default expression).
+			 */
+			if (values_attrno != 0 && apply_default && unused_values_attrnos)
+				*unused_values_attrnos = bms_add_member(*unused_values_attrnos,
+														values_attrno);
+		}
+
+		/*
+		 * Updates to identity and generated columns follow the same rules as
+		 * above, except that UPDATE doesn't admit OVERRIDING clauses.  Also,
+		 * the source can't be a VALUES RTE, so we needn't consider that.
+		 */
+		if (commandType == CMD_UPDATE)
+		{
+			if (att_tup->attidentity == ATTRIBUTE_IDENTITY_ALWAYS &&
+				new_tle && !apply_default)
+				ereport(ERROR,
+						(errcode(ERRCODE_GENERATED_ALWAYS),
+						 errmsg("column \"%s\" can only be updated to DEFAULT",
+								NameStr(att_tup->attname)),
+						 errdetail("Column \"%s\" is an identity column defined as GENERATED ALWAYS.",
+								   NameStr(att_tup->attname))));
+
+			if (att_tup->attgenerated && new_tle && !apply_default)
+				ereport(ERROR,
+						(errcode(ERRCODE_GENERATED_ALWAYS),
+						 errmsg("column \"%s\" can only be updated to DEFAULT",
+								NameStr(att_tup->attname)),
+						 errdetail("Column \"%s\" is a generated column.",
+								   NameStr(att_tup->attname))));
+		}
+
+		if (att_tup->attgenerated)
+		{
+			/*
+			 * stored generated column will be fixed in executor
+			 */
+			new_tle = NULL;
+		}
+		else if (apply_default)
+		{
+			Node	   *new_expr;
+
+			new_expr = build_column_default(target_relation, attrno);
+
+			/*
+			 * If there is no default (ie, default is effectively NULL), we
+			 * can omit the tlist entry in the INSERT case, since the planner
+			 * can insert a NULL for itself, and there's no point in spending
+			 * any more rewriter cycles on the entry.  But in the UPDATE case
+			 * we've got to explicitly set the column to NULL.
+			 */
+			if (!new_expr)
+			{
+				if (commandType == CMD_INSERT)
+					new_tle = NULL;
+				else
+				{
+					new_expr = (Node *) makeConst(att_tup->atttypid,
+												  -1,
+												  att_tup->attcollation,
+												  att_tup->attlen,
+												  (Datum) 0,
+												  true, /* isnull */
+												  att_tup->attbyval);
+					/* this is to catch a NOT NULL domain constraint */
+					new_expr = coerce_to_domain(new_expr,
+												InvalidOid, -1,
+												att_tup->atttypid,
+												COERCION_IMPLICIT,
+												COERCE_IMPLICIT_CAST,
+												-1,
+												false);
+				}
+			}
+
+			if (new_expr)
+				new_tle = makeTargetEntry((Expr *) new_expr,
+										  attrno,
+										  pstrdup(NameStr(att_tup->attname)),
+										  false);
+		}
+
+		if (new_tle)
+			new_tlist = lappend(new_tlist, new_tle);
+	}
+
+	pfree(new_tles);
+
+	return list_concat(new_tlist, junk_tlist);
+}
+
+
+/*
+ * Convert a matched TLE from the original tlist into a correct new TLE.
+ *
+ * This routine detects and handles multiple assignments to the same target
+ * attribute.  (The attribute name is needed only for error messages.)
+ */
+static TargetEntry *
+process_matched_tle(TargetEntry *src_tle,
+					TargetEntry *prior_tle,
+					const char *attrName)
+{
+	TargetEntry *result;
+	CoerceToDomain *coerce_expr = NULL;
+	Node	   *src_expr;
+	Node	   *prior_expr;
+	Node	   *src_input;
+	Node	   *prior_input;
+	Node	   *priorbottom;
+	Node	   *newexpr;
+
+	if (prior_tle == NULL)
+	{
+		/*
+		 * Normal case where this is the first assignment to the attribute.
+		 */
+		return src_tle;
+	}
+
+	/*----------
+	 * Multiple assignments to same attribute.  Allow only if all are
+	 * FieldStore or SubscriptingRef assignment operations.  This is a bit
+	 * tricky because what we may actually be looking at is a nest of
+	 * such nodes; consider
+	 *		UPDATE tab SET col.fld1.subfld1 = x, col.fld2.subfld2 = y
+	 * The two expressions produced by the parser will look like
+	 *		FieldStore(col, fld1, FieldStore(placeholder, subfld1, x))
+	 *		FieldStore(col, fld2, FieldStore(placeholder, subfld2, y))
+	 * However, we can ignore the substructure and just consider the top
+	 * FieldStore or SubscriptingRef from each assignment, because it works to
+	 * combine these as
+	 *		FieldStore(FieldStore(col, fld1,
+	 *							  FieldStore(placeholder, subfld1, x)),
+	 *				   fld2, FieldStore(placeholder, subfld2, y))
+	 * Note the leftmost expression goes on the inside so that the
+	 * assignments appear to occur left-to-right.
+	 *
+	 * For FieldStore, instead of nesting we can generate a single
+	 * FieldStore with multiple target fields.  We must nest when
+	 * SubscriptingRefs are involved though.
+	 *
+	 * As a further complication, the destination column might be a domain,
+	 * resulting in each assignment containing a CoerceToDomain node over a
+	 * FieldStore or SubscriptingRef.  These should have matching target
+	 * domains, so we strip them and reconstitute a single CoerceToDomain over
+	 * the combined FieldStore/SubscriptingRef nodes.  (Notice that this has the
+	 * result that the domain's checks are applied only after we do all the
+	 * field or element updates, not after each one.  This is arguably desirable.)
+	 *----------
+	 */
+	src_expr = (Node *) src_tle->expr;
+	prior_expr = (Node *) prior_tle->expr;
+
+	if (src_expr && IsA(src_expr, CoerceToDomain) &&
+		prior_expr && IsA(prior_expr, CoerceToDomain) &&
+		((CoerceToDomain *) src_expr)->resulttype ==
+		((CoerceToDomain *) prior_expr)->resulttype)
+	{
+		/* we assume without checking that resulttypmod/resultcollid match */
+		coerce_expr = (CoerceToDomain *) src_expr;
+		src_expr = (Node *) ((CoerceToDomain *) src_expr)->arg;
+		prior_expr = (Node *) ((CoerceToDomain *) prior_expr)->arg;
+	}
+
+	src_input = get_assignment_input(src_expr);
+	prior_input = get_assignment_input(prior_expr);
+	if (src_input == NULL ||
+		prior_input == NULL ||
+		exprType(src_expr) != exprType(prior_expr))
+		ereport(ERROR,
+				(errcode(ERRCODE_SYNTAX_ERROR),
+				 errmsg("multiple assignments to same column \"%s\"",
+						attrName)));
+
+	/*
+	 * Prior TLE could be a nest of assignments if we do this more than once.
+	 */
+	priorbottom = prior_input;
+	for (;;)
+	{
+		Node	   *newbottom = get_assignment_input(priorbottom);
+
+		if (newbottom == NULL)
+			break;				/* found the original Var reference */
+		priorbottom = newbottom;
+	}
+	if (!equal(priorbottom, src_input))
+		ereport(ERROR,
+				(errcode(ERRCODE_SYNTAX_ERROR),
+				 errmsg("multiple assignments to same column \"%s\"",
+						attrName)));
+
+	/*
+	 * Looks OK to nest 'em.
+	 */
+	if (IsA(src_expr, FieldStore))
+	{
+		FieldStore *fstore = makeNode(FieldStore);
+
+		if (IsA(prior_expr, FieldStore))
+		{
+			/* combine the two */
+			memcpy(fstore, prior_expr, sizeof(FieldStore));
+			fstore->newvals =
+				list_concat_copy(((FieldStore *) prior_expr)->newvals,
+								 ((FieldStore *) src_expr)->newvals);
+			fstore->fieldnums =
+				list_concat_copy(((FieldStore *) prior_expr)->fieldnums,
+								 ((FieldStore *) src_expr)->fieldnums);
+		}
+		else
+		{
+			/* general case, just nest 'em */
+			memcpy(fstore, src_expr, sizeof(FieldStore));
+			fstore->arg = (Expr *) prior_expr;
+		}
+		newexpr = (Node *) fstore;
+	}
+	else if (IsA(src_expr, SubscriptingRef))
+	{
+		SubscriptingRef *sbsref = makeNode(SubscriptingRef);
+
+		memcpy(sbsref, src_expr, sizeof(SubscriptingRef));
+		sbsref->refexpr = (Expr *) prior_expr;
+		newexpr = (Node *) sbsref;
+	}
+	else
+	{
+		elog(ERROR, "cannot happen");
+		newexpr = NULL;
+	}
+
+	if (coerce_expr)
+	{
+		/* put back the CoerceToDomain */
+		CoerceToDomain *newcoerce = makeNode(CoerceToDomain);
+
+		memcpy(newcoerce, coerce_expr, sizeof(CoerceToDomain));
+		newcoerce->arg = (Expr *) newexpr;
+		newexpr = (Node *) newcoerce;
+	}
+
+	result = flatCopyTargetEntry(src_tle);
+	result->expr = (Expr *) newexpr;
+	return result;
+}
+
+/*
+ * If node is an assignment node, return its input; else return NULL
+ */
+static Node *
+get_assignment_input(Node *node)
+{
+	if (node == NULL)
+		return NULL;
+	if (IsA(node, FieldStore))
+	{
+		FieldStore *fstore = (FieldStore *) node;
+
+		return (Node *) fstore->arg;
+	}
+	else if (IsA(node, SubscriptingRef))
+	{
+		SubscriptingRef *sbsref = (SubscriptingRef *) node;
+
+		if (sbsref->refassgnexpr == NULL)
+			return NULL;
+
+		return (Node *) sbsref->refexpr;
+	}
+
+	return NULL;
+}
+
+/*
+ * Make an expression tree for the default value for a column.
+ *
+ * If there is no default, return a NULL instead.
+ */
+Node *
+build_column_default(Relation rel, int attrno)
+{
+	TupleDesc	rd_att = rel->rd_att;
+	Form_pg_attribute att_tup = TupleDescAttr(rd_att, attrno - 1);
+	Oid			atttype = att_tup->atttypid;
+	int32		atttypmod = att_tup->atttypmod;
+	Node	   *expr = NULL;
+	Oid			exprtype;
+
+	if (att_tup->attidentity)
+	{
+		NextValueExpr *nve = makeNode(NextValueExpr);
+
+		nve->seqid = getIdentitySequence(RelationGetRelid(rel), attrno, false);
+		nve->typeId = att_tup->atttypid;
+
+		return (Node *) nve;
+	}
+
+	/*
+	 * If relation has a default for this column, fetch that expression.
+	 */
+	if (att_tup->atthasdef)
+	{
+		if (rd_att->constr && rd_att->constr->num_defval > 0)
+		{
+			AttrDefault *defval = rd_att->constr->defval;
+			int			ndef = rd_att->constr->num_defval;
+
+			while (--ndef >= 0)
+			{
+				if (attrno == defval[ndef].adnum)
+				{
+					/* Found it, convert string representation to node tree. */
+					expr = stringToNode(defval[ndef].adbin);
+					break;
+				}
+			}
+		}
+		if (expr == NULL)
+			elog(ERROR, "default expression not found for attribute %d of relation \"%s\"",
+				 attrno, RelationGetRelationName(rel));
+	}
+
+	/*
+	 * No per-column default, so look for a default for the type itself.  But
+	 * not for generated columns.
+	 */
+	if (expr == NULL && !att_tup->attgenerated)
+		expr = get_typdefault(atttype);
+
+	if (expr == NULL)
+		return NULL;			/* No default anywhere */
+
+	/*
+	 * Make sure the value is coerced to the target column type; this will
+	 * generally be true already, but there seem to be some corner cases
+	 * involving domain defaults where it might not be true. This should match
+	 * the parser's processing of non-defaulted expressions --- see
+	 * transformAssignedExpr().
+	 */
+	exprtype = exprType(expr);
+
+	expr = coerce_to_target_type(NULL,	/* no UNKNOWN params here */
+								 expr, exprtype,
+								 atttype, atttypmod,
+								 COERCION_ASSIGNMENT,
+								 COERCE_IMPLICIT_CAST,
+								 -1);
+	if (expr == NULL)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATATYPE_MISMATCH),
+				 errmsg("column \"%s\" is of type %s"
+						" but default expression is of type %s",
+						NameStr(att_tup->attname),
+						format_type_be(atttype),
+						format_type_be(exprtype)),
+				 errhint("You will need to rewrite or cast the expression.")));
+
+	return expr;
+}
+
+
+/* Does VALUES RTE contain any SetToDefault items? */
+static bool
+searchForDefault(RangeTblEntry *rte)
+{
+	ListCell   *lc;
+
+	foreach(lc, rte->values_lists)
+	{
+		List	   *sublist = (List *) lfirst(lc);
+		ListCell   *lc2;
+
+		foreach(lc2, sublist)
+		{
+			Node	   *col = (Node *) lfirst(lc2);
+
+			if (IsA(col, SetToDefault))
+				return true;
+		}
+	}
+	return false;
+}
+
+
+/*
+ * Search a VALUES RTE for columns that contain only SetToDefault items,
+ * returning a Bitmapset containing the attribute numbers of any such columns.
+ */
+static Bitmapset *
+findDefaultOnlyColumns(RangeTblEntry *rte)
+{
+	Bitmapset  *default_only_cols = NULL;
+	ListCell   *lc;
+
+	foreach(lc, rte->values_lists)
+	{
+		List	   *sublist = (List *) lfirst(lc);
+		ListCell   *lc2;
+		int			i;
+
+		if (default_only_cols == NULL)
+		{
+			/* Populate the initial result bitmap from the first row */
+			i = 0;
+			foreach(lc2, sublist)
+			{
+				Node	   *col = (Node *) lfirst(lc2);
+
+				i++;
+				if (IsA(col, SetToDefault))
+					default_only_cols = bms_add_member(default_only_cols, i);
+			}
+		}
+		else
+		{
+			/* Update the result bitmap from this next row */
+			i = 0;
+			foreach(lc2, sublist)
+			{
+				Node	   *col = (Node *) lfirst(lc2);
+
+				i++;
+				if (!IsA(col, SetToDefault))
+					default_only_cols = bms_del_member(default_only_cols, i);
+			}
+		}
+
+		/*
+		 * If no column in the rows read so far contains only DEFAULT items,
+		 * we are done.
+		 */
+		if (bms_is_empty(default_only_cols))
+			break;
+	}
+
+	return default_only_cols;
+}
+
+
+/*
+ * When processing INSERT ... VALUES with a VALUES RTE (ie, multiple VALUES
+ * lists), we have to replace any DEFAULT items in the VALUES lists with
+ * the appropriate default expressions.  The other aspects of targetlist
+ * rewriting need be applied only to the query's targetlist proper.
+ *
+ * For an auto-updatable view, each DEFAULT item in the VALUES list is
+ * replaced with the default from the view, if it has one.  Otherwise it is
+ * left untouched so that the underlying base relation's default can be
+ * applied instead (when we later recurse to here after rewriting the query
+ * to refer to the base relation instead of the view).
+ *
+ * For other types of relation, including rule- and trigger-updatable views,
+ * all DEFAULT items are replaced, and if the target relation doesn't have a
+ * default, the value is explicitly set to NULL.
+ *
+ * Additionally, if force_nulls is true, the target relation's defaults are
+ * ignored and all DEFAULT items in the VALUES list are explicitly set to
+ * NULL, regardless of the target relation's type.  This is used for the
+ * product queries generated by DO ALSO rules attached to an auto-updatable
+ * view, for which we will have already called this function with force_nulls
+ * false.  For these product queries, we must then force any remaining DEFAULT
+ * items to NULL to provide concrete values for the rule actions.
+ * Essentially, this is a mix of the 2 cases above --- the original query is
+ * an insert into an auto-updatable view, and the product queries are inserts
+ * into a rule-updatable view.
+ *
+ * Finally, if a DEFAULT item is found in a column mentioned in unused_cols,
+ * it is explicitly set to NULL.  This happens for columns in the VALUES RTE
+ * whose corresponding targetlist entries have already been replaced with the
+ * relation's default expressions, so that any values in those columns of the
+ * VALUES RTE are no longer used.  This can happen for identity and generated
+ * columns (if INSERT ... OVERRIDING USER VALUE is used, or all the values to
+ * be inserted are DEFAULT).  In principle we could replace all entries in
+ * such a column with NULL, whether DEFAULT or not; but it doesn't seem worth
+ * the trouble.
+ *
+ * Note that we may have subscripted or field assignment targetlist entries,
+ * as well as more complex expressions from already-replaced DEFAULT items if
+ * we have recursed to here for an auto-updatable view. However, it ought to
+ * be impossible for such entries to have DEFAULTs assigned to them, except
+ * for unused columns, as described above --- we should only have to replace
+ * DEFAULT items for targetlist entries that contain simple Vars referencing
+ * the VALUES RTE, or which are no longer referred to by the targetlist.
+ *
+ * Returns true if all DEFAULT items were replaced, and false if some were
+ * left untouched.
+ */
+static bool
+rewriteValuesRTE(Query *parsetree, RangeTblEntry *rte, int rti,
+				 Relation target_relation, bool force_nulls,
+				 Bitmapset *unused_cols)
+{
+	List	   *newValues;
+	ListCell   *lc;
+	bool		isAutoUpdatableView;
+	bool		allReplaced;
+	int			numattrs;
+	int		   *attrnos;
+
+	/*
+	 * Rebuilding all the lists is a pretty expensive proposition in a big
+	 * VALUES list, and it's a waste of time if there aren't any DEFAULT
+	 * placeholders.  So first scan to see if there are any.
+	 *
+	 * We skip this check if force_nulls is true, because we know that there
+	 * are DEFAULT items present in that case.
+	 */
+	if (!force_nulls && !searchForDefault(rte))
+		return true;			/* nothing to do */
+
+	/*
+	 * Scan the targetlist for entries referring to the VALUES RTE, and note
+	 * the target attributes. As noted above, we should only need to do this
+	 * for targetlist entries containing simple Vars --- nothing else in the
+	 * VALUES RTE should contain DEFAULT items (except possibly for unused
+	 * columns), and we complain if such a thing does occur.
+	 */
+	numattrs = list_length(linitial(rte->values_lists));
+	attrnos = (int *) palloc0(numattrs * sizeof(int));
+
+	foreach(lc, parsetree->targetList)
+	{
+		TargetEntry *tle = (TargetEntry *) lfirst(lc);
+
+		if (IsA(tle->expr, Var))
+		{
+			Var		   *var = (Var *) tle->expr;
+
+			if (var->varno == rti)
+			{
+				int			attrno = var->varattno;
+
+				Assert(attrno >= 1 && attrno <= numattrs);
+				attrnos[attrno - 1] = tle->resno;
+			}
+		}
+	}
+
+	/*
+	 * Check if the target relation is an auto-updatable view, in which case
+	 * unresolved defaults will be left untouched rather than being set to
+	 * NULL.  If force_nulls is true, we always set DEFAULT items to NULL, so
+	 * skip this check in that case --- it isn't an auto-updatable view.
+	 */
+	isAutoUpdatableView = false;
+	if (!force_nulls &&
+		target_relation->rd_rel->relkind == RELKIND_VIEW &&
+		!view_has_instead_trigger(target_relation, CMD_INSERT))
+	{
+		List	   *locks;
+		bool		hasUpdate;
+		bool		found;
+		ListCell   *l;
+
+		/* Look for an unconditional DO INSTEAD rule */
+		locks = matchLocks(CMD_INSERT, target_relation->rd_rules,
+						   parsetree->resultRelation, parsetree, &hasUpdate);
+
+		found = false;
+		foreach(l, locks)
+		{
+			RewriteRule *rule_lock = (RewriteRule *) lfirst(l);
+
+			if (rule_lock->isInstead &&
+				rule_lock->qual == NULL)
+			{
+				found = true;
+				break;
+			}
+		}
+
+		/*
+		 * If we didn't find an unconditional DO INSTEAD rule, assume that the
+		 * view is auto-updatable.  If it isn't, rewriteTargetView() will
+		 * throw an error.
+		 */
+		if (!found)
+			isAutoUpdatableView = true;
+	}
+
+	newValues = NIL;
+	allReplaced = true;
+	foreach(lc, rte->values_lists)
+	{
+		List	   *sublist = (List *) lfirst(lc);
+		List	   *newList = NIL;
+		ListCell   *lc2;
+		int			i;
+
+		Assert(list_length(sublist) == numattrs);
+
+		i = 0;
+		foreach(lc2, sublist)
+		{
+			Node	   *col = (Node *) lfirst(lc2);
+			int			attrno = attrnos[i++];
+
+			if (IsA(col, SetToDefault))
+			{
+				Form_pg_attribute att_tup;
+				Node	   *new_expr;
+
+				/*
+				 * If this column isn't used, just replace the DEFAULT with
+				 * NULL (attrno will be 0 in this case because the targetlist
+				 * entry will have been replaced by the default expression).
+				 */
+				if (bms_is_member(i, unused_cols))
+				{
+					SetToDefault *def = (SetToDefault *) col;
+
+					newList = lappend(newList,
+									  makeNullConst(def->typeId,
+													def->typeMod,
+													def->collation));
+					continue;
+				}
+
+				if (attrno == 0)
+					elog(ERROR, "cannot set value in column %d to DEFAULT", i);
+				att_tup = TupleDescAttr(target_relation->rd_att, attrno - 1);
+
+				if (!force_nulls && !att_tup->attisdropped)
+					new_expr = build_column_default(target_relation, attrno);
+				else
+					new_expr = NULL;	/* force a NULL if dropped */
+
+				/*
+				 * If there is no default (ie, default is effectively NULL),
+				 * we've got to explicitly set the column to NULL, unless the
+				 * target relation is an auto-updatable view.
+				 */
+				if (!new_expr)
+				{
+					if (isAutoUpdatableView)
+					{
+						/* Leave the value untouched */
+						newList = lappend(newList, col);
+						allReplaced = false;
+						continue;
+					}
+
+					new_expr = (Node *) makeConst(att_tup->atttypid,
+												  -1,
+												  att_tup->attcollation,
+												  att_tup->attlen,
+												  (Datum) 0,
+												  true, /* isnull */
+												  att_tup->attbyval);
+					/* this is to catch a NOT NULL domain constraint */
+					new_expr = coerce_to_domain(new_expr,
+												InvalidOid, -1,
+												att_tup->atttypid,
+												COERCION_IMPLICIT,
+												COERCE_IMPLICIT_CAST,
+												-1,
+												false);
+				}
+				newList = lappend(newList, new_expr);
+			}
+			else
+				newList = lappend(newList, col);
+		}
+		newValues = lappend(newValues, newList);
+	}
+	rte->values_lists = newValues;
+
+	pfree(attrnos);
+
+	return allReplaced;
+}
+
+
+/*
+ * Record in target_rte->extraUpdatedCols the indexes of any generated columns
+ * that depend on any columns mentioned in target_rte->updatedCols.
+ */
+void
+fill_extraUpdatedCols(RangeTblEntry *target_rte, Relation target_relation)
+{
+	TupleDesc	tupdesc = RelationGetDescr(target_relation);
+	TupleConstr *constr = tupdesc->constr;
+
+	target_rte->extraUpdatedCols = NULL;
+
+	if (constr && constr->has_generated_stored)
+	{
+		for (int i = 0; i < constr->num_defval; i++)
+		{
+			AttrDefault *defval = &constr->defval[i];
+			Node	   *expr;
+			Bitmapset  *attrs_used = NULL;
+
+			/* skip if not generated column */
+			if (!TupleDescAttr(tupdesc, defval->adnum - 1)->attgenerated)
+				continue;
+
+			/* identify columns this generated column depends on */
+			expr = stringToNode(defval->adbin);
+			pull_varattnos(expr, 1, &attrs_used);
+
+			if (bms_overlap(target_rte->updatedCols, attrs_used))
+				target_rte->extraUpdatedCols =
+					bms_add_member(target_rte->extraUpdatedCols,
+								   defval->adnum - FirstLowInvalidHeapAttributeNumber);
+		}
+	}
+}
+
+
+/*
+ * matchLocks -
+ *	  match the list of locks and returns the matching rules
+ */
+static List *
+matchLocks(CmdType event,
+		   RuleLock *rulelocks,
+		   int varno,
+		   Query *parsetree,
+		   bool *hasUpdate)
+{
+	List	   *matching_locks = NIL;
+	int			nlocks;
+	int			i;
+
+	if (rulelocks == NULL)
+		return NIL;
+
+	if (parsetree->commandType != CMD_SELECT)
+	{
+		if (parsetree->resultRelation != varno)
+			return NIL;
+	}
+
+	nlocks = rulelocks->numLocks;
+
+	for (i = 0; i < nlocks; i++)
+	{
+		RewriteRule *oneLock = rulelocks->rules[i];
+
+		if (oneLock->event == CMD_UPDATE)
+			*hasUpdate = true;
+
+		/*
+		 * Suppress ON INSERT/UPDATE/DELETE rules that are disabled or
+		 * configured to not fire during the current sessions replication
+		 * role. ON SELECT rules will always be applied in order to keep views
+		 * working even in LOCAL or REPLICA role.
+		 */
+		if (oneLock->event != CMD_SELECT)
+		{
+			if (SessionReplicationRole == SESSION_REPLICATION_ROLE_REPLICA)
+			{
+				if (oneLock->enabled == RULE_FIRES_ON_ORIGIN ||
+					oneLock->enabled == RULE_DISABLED)
+					continue;
+			}
+			else				/* ORIGIN or LOCAL ROLE */
+			{
+				if (oneLock->enabled == RULE_FIRES_ON_REPLICA ||
+					oneLock->enabled == RULE_DISABLED)
+					continue;
+			}
+		}
+
+		if (oneLock->event == event)
+		{
+			if (parsetree->commandType != CMD_SELECT ||
+				rangeTableEntry_used((Node *) parsetree, varno, 0))
+				matching_locks = lappend(matching_locks, oneLock);
+		}
+	}
+
+	return matching_locks;
+}
+
+
+/*
+ * ApplyRetrieveRule - expand an ON SELECT rule
+ */
+static Query *
+ApplyRetrieveRule(Query *parsetree,
+				  RewriteRule *rule,
+				  int rt_index,
+				  Relation relation,
+				  List *activeRIRs)
+{
+	Query	   *rule_action;
+	RangeTblEntry *rte,
+			   *subrte;
+	RowMarkClause *rc;
+
+	if (list_length(rule->actions) != 1)
+		elog(ERROR, "expected just one rule action");
+	if (rule->qual != NULL)
+		elog(ERROR, "cannot handle qualified ON SELECT rule");
+
+	if (rt_index == parsetree->resultRelation)
+	{
+		/*
+		 * We have a view as the result relation of the query, and it wasn't
+		 * rewritten by any rule.  This case is supported if there is an
+		 * INSTEAD OF trigger that will trap attempts to insert/update/delete
+		 * view rows.  The executor will check that; for the moment just plow
+		 * ahead.  We have two cases:
+		 *
+		 * For INSERT, we needn't do anything.  The unmodified RTE will serve
+		 * fine as the result relation.
+		 *
+		 * For UPDATE/DELETE, we need to expand the view so as to have source
+		 * data for the operation.  But we also need an unmodified RTE to
+		 * serve as the target.  So, copy the RTE and add the copy to the
+		 * rangetable.  Note that the copy does not get added to the jointree.
+		 * Also note that there's a hack in fireRIRrules to avoid calling this
+		 * function again when it arrives at the copied RTE.
+		 */
+		if (parsetree->commandType == CMD_INSERT)
+			return parsetree;
+		else if (parsetree->commandType == CMD_UPDATE ||
+				 parsetree->commandType == CMD_DELETE)
+		{
+			RangeTblEntry *newrte;
+			Var		   *var;
+			TargetEntry *tle;
+
+			rte = rt_fetch(rt_index, parsetree->rtable);
+			newrte = copyObject(rte);
+			parsetree->rtable = lappend(parsetree->rtable, newrte);
+			parsetree->resultRelation = list_length(parsetree->rtable);
+
+			/*
+			 * There's no need to do permissions checks twice, so wipe out the
+			 * permissions info for the original RTE (we prefer to keep the
+			 * bits set on the result RTE).
+			 */
+			rte->requiredPerms = 0;
+			rte->checkAsUser = InvalidOid;
+			rte->selectedCols = NULL;
+			rte->insertedCols = NULL;
+			rte->updatedCols = NULL;
+			rte->extraUpdatedCols = NULL;
+
+			/*
+			 * For the most part, Vars referencing the view should remain as
+			 * they are, meaning that they implicitly represent OLD values.
+			 * But in the RETURNING list if any, we want such Vars to
+			 * represent NEW values, so change them to reference the new RTE.
+			 *
+			 * Since ChangeVarNodes scribbles on the tree in-place, copy the
+			 * RETURNING list first for safety.
+			 */
+			parsetree->returningList = copyObject(parsetree->returningList);
+			ChangeVarNodes((Node *) parsetree->returningList, rt_index,
+						   parsetree->resultRelation, 0);
+
+			/*
+			 * To allow the executor to compute the original view row to pass
+			 * to the INSTEAD OF trigger, we add a resjunk whole-row Var
+			 * referencing the original RTE.  This will later get expanded
+			 * into a RowExpr computing all the OLD values of the view row.
+			 */
+			var = makeWholeRowVar(rte, rt_index, 0, false);
+			tle = makeTargetEntry((Expr *) var,
+								  list_length(parsetree->targetList) + 1,
+								  pstrdup("wholerow"),
+								  true);
+
+			parsetree->targetList = lappend(parsetree->targetList, tle);
+
+			/* Now, continue with expanding the original view RTE */
+		}
+		else
+			elog(ERROR, "unrecognized commandType: %d",
+				 (int) parsetree->commandType);
+	}
+
+	/*
+	 * Check if there's a FOR [KEY] UPDATE/SHARE clause applying to this view.
+	 *
+	 * Note: we needn't explicitly consider any such clauses appearing in
+	 * ancestor query levels; their effects have already been pushed down to
+	 * here by markQueryForLocking, and will be reflected in "rc".
+	 */
+	rc = get_parse_rowmark(parsetree, rt_index);
+
+	/*
+	 * Make a modifiable copy of the view query, and acquire needed locks on
+	 * the relations it mentions.  Force at least RowShareLock for all such
+	 * rels if there's a FOR [KEY] UPDATE/SHARE clause affecting this view.
+	 */
+	rule_action = copyObject(linitial(rule->actions));
+
+	AcquireRewriteLocks(rule_action, true, (rc != NULL));
+
+	/*
+	 * If FOR [KEY] UPDATE/SHARE of view, mark all the contained tables as
+	 * implicit FOR [KEY] UPDATE/SHARE, the same as the parser would have done
+	 * if the view's subquery had been written out explicitly.
+	 */
+	if (rc != NULL)
+		markQueryForLocking(rule_action, (Node *) rule_action->jointree,
+							rc->strength, rc->waitPolicy, true);
+
+	/*
+	 * Recursively expand any view references inside the view.
+	 *
+	 * Note: this must happen after markQueryForLocking.  That way, any UPDATE
+	 * permission bits needed for sub-views are initially applied to their
+	 * RTE_RELATION RTEs by markQueryForLocking, and then transferred to their
+	 * OLD rangetable entries by the action below (in a recursive call of this
+	 * routine).
+	 */
+	rule_action = fireRIRrules(rule_action, activeRIRs);
+
+	/*
+	 * Now, plug the view query in as a subselect, converting the relation's
+	 * original RTE to a subquery RTE.
+	 */
+	rte = rt_fetch(rt_index, parsetree->rtable);
+
+	rte->rtekind = RTE_SUBQUERY;
+	rte->subquery = rule_action;
+	rte->security_barrier = RelationIsSecurityView(relation);
+	/* Clear fields that should not be set in a subquery RTE */
+	rte->relid = InvalidOid;
+	rte->relkind = 0;
+	rte->rellockmode = 0;
+	rte->tablesample = NULL;
+	rte->inh = false;			/* must not be set for a subquery */
+
+	/*
+	 * We move the view's permission check data down to its rangetable. The
+	 * checks will actually be done against the OLD entry therein.
+	 */
+	subrte = rt_fetch(PRS2_OLD_VARNO, rule_action->rtable);
+	Assert(subrte->relid == relation->rd_id);
+	subrte->requiredPerms = rte->requiredPerms;
+	subrte->checkAsUser = rte->checkAsUser;
+	subrte->selectedCols = rte->selectedCols;
+	subrte->insertedCols = rte->insertedCols;
+	subrte->updatedCols = rte->updatedCols;
+	subrte->extraUpdatedCols = rte->extraUpdatedCols;
+
+	rte->requiredPerms = 0;		/* no permission check on subquery itself */
+	rte->checkAsUser = InvalidOid;
+	rte->selectedCols = NULL;
+	rte->insertedCols = NULL;
+	rte->updatedCols = NULL;
+	rte->extraUpdatedCols = NULL;
+
+	return parsetree;
+}
+
+/*
+ * Recursively mark all relations used by a view as FOR [KEY] UPDATE/SHARE.
+ *
+ * This may generate an invalid query, eg if some sub-query uses an
+ * aggregate.  We leave it to the planner to detect that.
+ *
+ * NB: this must agree with the parser's transformLockingClause() routine.
+ * However, unlike the parser we have to be careful not to mark a view's
+ * OLD and NEW rels for updating.  The best way to handle that seems to be
+ * to scan the jointree to determine which rels are used.
+ */
+static void
+markQueryForLocking(Query *qry, Node *jtnode,
+					LockClauseStrength strength, LockWaitPolicy waitPolicy,
+					bool pushedDown)
+{
+	if (jtnode == NULL)
+		return;
+	if (IsA(jtnode, RangeTblRef))
+	{
+		int			rti = ((RangeTblRef *) jtnode)->rtindex;
+		RangeTblEntry *rte = rt_fetch(rti, qry->rtable);
+
+		if (rte->rtekind == RTE_RELATION)
+		{
+			applyLockingClause(qry, rti, strength, waitPolicy, pushedDown);
+			rte->requiredPerms |= ACL_SELECT_FOR_UPDATE;
+		}
+		else if (rte->rtekind == RTE_SUBQUERY)
+		{
+			applyLockingClause(qry, rti, strength, waitPolicy, pushedDown);
+			/* FOR UPDATE/SHARE of subquery is propagated to subquery's rels */
+			markQueryForLocking(rte->subquery, (Node *) rte->subquery->jointree,
+								strength, waitPolicy, true);
+		}
+		/* other RTE types are unaffected by FOR UPDATE */
+	}
+	else if (IsA(jtnode, FromExpr))
+	{
+		FromExpr   *f = (FromExpr *) jtnode;
+		ListCell   *l;
+
+		foreach(l, f->fromlist)
+			markQueryForLocking(qry, lfirst(l), strength, waitPolicy, pushedDown);
+	}
+	else if (IsA(jtnode, JoinExpr))
+	{
+		JoinExpr   *j = (JoinExpr *) jtnode;
+
+		markQueryForLocking(qry, j->larg, strength, waitPolicy, pushedDown);
+		markQueryForLocking(qry, j->rarg, strength, waitPolicy, pushedDown);
+	}
+	else
+		elog(ERROR, "unrecognized node type: %d",
+			 (int) nodeTag(jtnode));
+}
+
+
+/*
+ * fireRIRonSubLink -
+ *	Apply fireRIRrules() to each SubLink (subselect in expression) found
+ *	in the given tree.
+ *
+ * NOTE: although this has the form of a walker, we cheat and modify the
+ * SubLink nodes in-place.  It is caller's responsibility to ensure that
+ * no unwanted side-effects occur!
+ *
+ * This is unlike most of the other routines that recurse into subselects,
+ * because we must take control at the SubLink node in order to replace
+ * the SubLink's subselect link with the possibly-rewritten subquery.
+ */
+static bool
+fireRIRonSubLink(Node *node, List *activeRIRs)
+{
+	if (node == NULL)
+		return false;
+	if (IsA(node, SubLink))
+	{
+		SubLink    *sub = (SubLink *) node;
+
+		/* Do what we came for */
+		sub->subselect = (Node *) fireRIRrules((Query *) sub->subselect,
+											   activeRIRs);
+		/* Fall through to process lefthand args of SubLink */
+	}
+
+	/*
+	 * Do NOT recurse into Query nodes, because fireRIRrules already processed
+	 * subselects of subselects for us.
+	 */
+	return expression_tree_walker(node, fireRIRonSubLink,
+								  (void *) activeRIRs);
+}
+
+
+/*
+ * fireRIRrules -
+ *	Apply all RIR rules on each rangetable entry in the given query
+ *
+ * activeRIRs is a list of the OIDs of views we're already processing RIR
+ * rules for, used to detect/reject recursion.
+ */
+static Query *
+fireRIRrules(Query *parsetree, List *activeRIRs)
+{
+	int			origResultRelation = parsetree->resultRelation;
+	int			rt_index;
+	ListCell   *lc;
+
+	/*
+	 * Expand SEARCH and CYCLE clauses in CTEs.
+	 *
+	 * This is just a convenient place to do this, since we are already
+	 * looking at each Query.
+	 */
+	foreach(lc, parsetree->cteList)
+	{
+		CommonTableExpr *cte = lfirst_node(CommonTableExpr, lc);
+
+		if (cte->search_clause || cte->cycle_clause)
+		{
+			cte = rewriteSearchAndCycle(cte);
+			lfirst(lc) = cte;
+		}
+	}
+
+	/*
+	 * don't try to convert this into a foreach loop, because rtable list can
+	 * get changed each time through...
+	 */
+	rt_index = 0;
+	while (rt_index < list_length(parsetree->rtable))
+	{
+		RangeTblEntry *rte;
+		Relation	rel;
+		List	   *locks;
+		RuleLock   *rules;
+		RewriteRule *rule;
+		int			i;
+
+		++rt_index;
+
+		rte = rt_fetch(rt_index, parsetree->rtable);
+
+		/*
+		 * A subquery RTE can't have associated rules, so there's nothing to
+		 * do to this level of the query, but we must recurse into the
+		 * subquery to expand any rule references in it.
+		 */
+		if (rte->rtekind == RTE_SUBQUERY)
+		{
+			rte->subquery = fireRIRrules(rte->subquery, activeRIRs);
+			continue;
+		}
+
+		/*
+		 * Joins and other non-relation RTEs can be ignored completely.
+		 */
+		if (rte->rtekind != RTE_RELATION)
+			continue;
+
+		/*
+		 * Always ignore RIR rules for materialized views referenced in
+		 * queries.  (This does not prevent refreshing MVs, since they aren't
+		 * referenced in their own query definitions.)
+		 *
+		 * Note: in the future we might want to allow MVs to be conditionally
+		 * expanded as if they were regular views, if they are not scannable.
+		 * In that case this test would need to be postponed till after we've
+		 * opened the rel, so that we could check its state.
+		 */
+		if (rte->relkind == RELKIND_MATVIEW)
+			continue;
+
+		/*
+		 * In INSERT ... ON CONFLICT, ignore the EXCLUDED pseudo-relation;
+		 * even if it points to a view, we needn't expand it, and should not
+		 * because we want the RTE to remain of RTE_RELATION type.  Otherwise,
+		 * it would get changed to RTE_SUBQUERY type, which is an
+		 * untested/unsupported situation.
+		 */
+		if (parsetree->onConflict &&
+			rt_index == parsetree->onConflict->exclRelIndex)
+			continue;
+
+		/*
+		 * If the table is not referenced in the query, then we ignore it.
+		 * This prevents infinite expansion loop due to new rtable entries
+		 * inserted by expansion of a rule. A table is referenced if it is
+		 * part of the join set (a source table), or is referenced by any Var
+		 * nodes, or is the result table.
+		 */
+		if (rt_index != parsetree->resultRelation &&
+			!rangeTableEntry_used((Node *) parsetree, rt_index, 0))
+			continue;
+
+		/*
+		 * Also, if this is a new result relation introduced by
+		 * ApplyRetrieveRule, we don't want to do anything more with it.
+		 */
+		if (rt_index == parsetree->resultRelation &&
+			rt_index != origResultRelation)
+			continue;
+
+		/*
+		 * We can use NoLock here since either the parser or
+		 * AcquireRewriteLocks should have locked the rel already.
+		 */
+		rel = table_open(rte->relid, NoLock);
+
+		/*
+		 * Collect the RIR rules that we must apply
+		 */
+		rules = rel->rd_rules;
+		if (rules != NULL)
+		{
+			locks = NIL;
+			for (i = 0; i < rules->numLocks; i++)
+			{
+				rule = rules->rules[i];
+				if (rule->event != CMD_SELECT)
+					continue;
+
+				locks = lappend(locks, rule);
+			}
+
+			/*
+			 * If we found any, apply them --- but first check for recursion!
+			 */
+			if (locks != NIL)
+			{
+				ListCell   *l;
+
+				if (list_member_oid(activeRIRs, RelationGetRelid(rel)))
+					ereport(ERROR,
+							(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
+							 errmsg("infinite recursion detected in rules for relation \"%s\"",
+									RelationGetRelationName(rel))));
+				activeRIRs = lappend_oid(activeRIRs, RelationGetRelid(rel));
+
+				foreach(l, locks)
+				{
+					rule = lfirst(l);
+
+					parsetree = ApplyRetrieveRule(parsetree,
+												  rule,
+												  rt_index,
+												  rel,
+												  activeRIRs);
+				}
+
+				activeRIRs = list_delete_last(activeRIRs);
+			}
+		}
+
+		table_close(rel, NoLock);
+	}
+
+	/* Recurse into subqueries in WITH */
+	foreach(lc, parsetree->cteList)
+	{
+		CommonTableExpr *cte = (CommonTableExpr *) lfirst(lc);
+
+		cte->ctequery = (Node *)
+			fireRIRrules((Query *) cte->ctequery, activeRIRs);
+	}
+
+	/*
+	 * Recurse into sublink subqueries, too.  But we already did the ones in
+	 * the rtable and cteList.
+	 */
+	if (parsetree->hasSubLinks)
+		query_tree_walker(parsetree, fireRIRonSubLink, (void *) activeRIRs,
+						  QTW_IGNORE_RC_SUBQUERIES);
+
+	/*
+	 * Apply any row-level security policies.  We do this last because it
+	 * requires special recursion detection if the new quals have sublink
+	 * subqueries, and if we did it in the loop above query_tree_walker would
+	 * then recurse into those quals a second time.
+	 */
+	rt_index = 0;
+	foreach(lc, parsetree->rtable)
+	{
+		RangeTblEntry *rte = (RangeTblEntry *) lfirst(lc);
+		Relation	rel;
+		List	   *securityQuals;
+		List	   *withCheckOptions;
+		bool		hasRowSecurity;
+		bool		hasSubLinks;
+
+		++rt_index;
+
+		/* Only normal relations can have RLS policies */
+		if (rte->rtekind != RTE_RELATION ||
+			(rte->relkind != RELKIND_RELATION &&
+			 rte->relkind != RELKIND_PARTITIONED_TABLE))
+			continue;
+
+		rel = table_open(rte->relid, NoLock);
+
+		/*
+		 * Fetch any new security quals that must be applied to this RTE.
+		 */
+		get_row_security_policies(parsetree, rte, rt_index,
+								  &securityQuals, &withCheckOptions,
+								  &hasRowSecurity, &hasSubLinks);
+
+		if (securityQuals != NIL || withCheckOptions != NIL)
+		{
+			if (hasSubLinks)
+			{
+				acquireLocksOnSubLinks_context context;
+
+				/*
+				 * Recursively process the new quals, checking for infinite
+				 * recursion.
+				 */
+				if (list_member_oid(activeRIRs, RelationGetRelid(rel)))
+					ereport(ERROR,
+							(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
+							 errmsg("infinite recursion detected in policy for relation \"%s\"",
+									RelationGetRelationName(rel))));
+
+				activeRIRs = lappend_oid(activeRIRs, RelationGetRelid(rel));
+
+				/*
+				 * get_row_security_policies just passed back securityQuals
+				 * and/or withCheckOptions, and there were SubLinks, make sure
+				 * we lock any relations which are referenced.
+				 *
+				 * These locks would normally be acquired by the parser, but
+				 * securityQuals and withCheckOptions are added post-parsing.
+				 */
+				context.for_execute = true;
+				(void) acquireLocksOnSubLinks((Node *) securityQuals, &context);
+				(void) acquireLocksOnSubLinks((Node *) withCheckOptions,
+											  &context);
+
+				/*
+				 * Now that we have the locks on anything added by
+				 * get_row_security_policies, fire any RIR rules for them.
+				 */
+				expression_tree_walker((Node *) securityQuals,
+									   fireRIRonSubLink, (void *) activeRIRs);
+
+				expression_tree_walker((Node *) withCheckOptions,
+									   fireRIRonSubLink, (void *) activeRIRs);
+
+				activeRIRs = list_delete_last(activeRIRs);
+			}
+
+			/*
+			 * Add the new security barrier quals to the start of the RTE's
+			 * list so that they get applied before any existing barrier quals
+			 * (which would have come from a security-barrier view, and should
+			 * get lower priority than RLS conditions on the table itself).
+			 */
+			rte->securityQuals = list_concat(securityQuals,
+											 rte->securityQuals);
+
+			parsetree->withCheckOptions = list_concat(withCheckOptions,
+													  parsetree->withCheckOptions);
+		}
+
+		/*
+		 * Make sure the query is marked correctly if row-level security
+		 * applies, or if the new quals had sublinks.
+		 */
+		if (hasRowSecurity)
+			parsetree->hasRowSecurity = true;
+		if (hasSubLinks)
+			parsetree->hasSubLinks = true;
+
+		table_close(rel, NoLock);
+	}
+
+	return parsetree;
+}
+
+
+/*
+ * Modify the given query by adding 'AND rule_qual IS NOT TRUE' to its
+ * qualification.  This is used to generate suitable "else clauses" for
+ * conditional INSTEAD rules.  (Unfortunately we must use "x IS NOT TRUE",
+ * not just "NOT x" which the planner is much smarter about, else we will
+ * do the wrong thing when the qual evaluates to NULL.)
+ *
+ * The rule_qual may contain references to OLD or NEW.  OLD references are
+ * replaced by references to the specified rt_index (the relation that the
+ * rule applies to).  NEW references are only possible for INSERT and UPDATE
+ * queries on the relation itself, and so they should be replaced by copies
+ * of the related entries in the query's own targetlist.
+ */
+static Query *
+CopyAndAddInvertedQual(Query *parsetree,
+					   Node *rule_qual,
+					   int rt_index,
+					   CmdType event)
+{
+	/* Don't scribble on the passed qual (it's in the relcache!) */
+	Node	   *new_qual = copyObject(rule_qual);
+	acquireLocksOnSubLinks_context context;
+
+	context.for_execute = true;
+
+	/*
+	 * In case there are subqueries in the qual, acquire necessary locks and
+	 * fix any deleted JOIN RTE entries.  (This is somewhat redundant with
+	 * rewriteRuleAction, but not entirely ... consider restructuring so that
+	 * we only need to process the qual this way once.)
+	 */
+	(void) acquireLocksOnSubLinks(new_qual, &context);
+
+	/* Fix references to OLD */
+	ChangeVarNodes(new_qual, PRS2_OLD_VARNO, rt_index, 0);
+	/* Fix references to NEW */
+	if (event == CMD_INSERT || event == CMD_UPDATE)
+		new_qual = ReplaceVarsFromTargetList(new_qual,
+											 PRS2_NEW_VARNO,
+											 0,
+											 rt_fetch(rt_index,
+													  parsetree->rtable),
+											 parsetree->targetList,
+											 (event == CMD_UPDATE) ?
+											 REPLACEVARS_CHANGE_VARNO :
+											 REPLACEVARS_SUBSTITUTE_NULL,
+											 rt_index,
+											 &parsetree->hasSubLinks);
+	/* And attach the fixed qual */
+	AddInvertedQual(parsetree, new_qual);
+
+	return parsetree;
+}
+
+
+/*
+ *	fireRules -
+ *	   Iterate through rule locks applying rules.
+ *
+ * Input arguments:
+ *	parsetree - original query
+ *	rt_index - RT index of result relation in original query
+ *	event - type of rule event
+ *	locks - list of rules to fire
+ * Output arguments:
+ *	*instead_flag - set true if any unqualified INSTEAD rule is found
+ *					(must be initialized to false)
+ *	*returning_flag - set true if we rewrite RETURNING clause in any rule
+ *					(must be initialized to false)
+ *	*qual_product - filled with modified original query if any qualified
+ *					INSTEAD rule is found (must be initialized to NULL)
+ * Return value:
+ *	list of rule actions adjusted for use with this query
+ *
+ * Qualified INSTEAD rules generate their action with the qualification
+ * condition added.  They also generate a modified version of the original
+ * query with the negated qualification added, so that it will run only for
+ * rows that the qualified action doesn't act on.  (If there are multiple
+ * qualified INSTEAD rules, we AND all the negated quals onto a single
+ * modified original query.)  We won't execute the original, unmodified
+ * query if we find either qualified or unqualified INSTEAD rules.  If
+ * we find both, the modified original query is discarded too.
+ */
+static List *
+fireRules(Query *parsetree,
+		  int rt_index,
+		  CmdType event,
+		  List *locks,
+		  bool *instead_flag,
+		  bool *returning_flag,
+		  Query **qual_product)
+{
+	List	   *results = NIL;
+	ListCell   *l;
+
+	foreach(l, locks)
+	{
+		RewriteRule *rule_lock = (RewriteRule *) lfirst(l);
+		Node	   *event_qual = rule_lock->qual;
+		List	   *actions = rule_lock->actions;
+		QuerySource qsrc;
+		ListCell   *r;
+
+		/* Determine correct QuerySource value for actions */
+		if (rule_lock->isInstead)
+		{
+			if (event_qual != NULL)
+				qsrc = QSRC_QUAL_INSTEAD_RULE;
+			else
+			{
+				qsrc = QSRC_INSTEAD_RULE;
+				*instead_flag = true;	/* report unqualified INSTEAD */
+			}
+		}
+		else
+			qsrc = QSRC_NON_INSTEAD_RULE;
+
+		if (qsrc == QSRC_QUAL_INSTEAD_RULE)
+		{
+			/*
+			 * If there are INSTEAD rules with qualifications, the original
+			 * query is still performed. But all the negated rule
+			 * qualifications of the INSTEAD rules are added so it does its
+			 * actions only in cases where the rule quals of all INSTEAD rules
+			 * are false. Think of it as the default action in a case. We save
+			 * this in *qual_product so RewriteQuery() can add it to the query
+			 * list after we mangled it up enough.
+			 *
+			 * If we have already found an unqualified INSTEAD rule, then
+			 * *qual_product won't be used, so don't bother building it.
+			 */
+			if (!*instead_flag)
+			{
+				if (*qual_product == NULL)
+					*qual_product = copyObject(parsetree);
+				*qual_product = CopyAndAddInvertedQual(*qual_product,
+													   event_qual,
+													   rt_index,
+													   event);
+			}
+		}
+
+		/* Now process the rule's actions and add them to the result list */
+		foreach(r, actions)
+		{
+			Query	   *rule_action = lfirst(r);
+
+			if (rule_action->commandType == CMD_NOTHING)
+				continue;
+
+			rule_action = rewriteRuleAction(parsetree, rule_action,
+											event_qual, rt_index, event,
+											returning_flag);
+
+			rule_action->querySource = qsrc;
+			rule_action->canSetTag = false; /* might change later */
+
+			results = lappend(results, rule_action);
+		}
+	}
+
+	return results;
+}
+
+
+/*
+ * get_view_query - get the Query from a view's _RETURN rule.
+ *
+ * Caller should have verified that the relation is a view, and therefore
+ * we should find an ON SELECT action.
+ *
+ * Note that the pointer returned is into the relcache and therefore must
+ * be treated as read-only to the caller and not modified or scribbled on.
+ */
+Query *
+get_view_query(Relation view)
+{
+	int			i;
+
+	Assert(view->rd_rel->relkind == RELKIND_VIEW);
+
+	for (i = 0; i < view->rd_rules->numLocks; i++)
+	{
+		RewriteRule *rule = view->rd_rules->rules[i];
+
+		if (rule->event == CMD_SELECT)
+		{
+			/* A _RETURN rule should have only one action */
+			if (list_length(rule->actions) != 1)
+				elog(ERROR, "invalid _RETURN rule action specification");
+
+			return (Query *) linitial(rule->actions);
+		}
+	}
+
+	elog(ERROR, "failed to find _RETURN rule for view");
+	return NULL;				/* keep compiler quiet */
+}
+
+
+/*
+ * view_has_instead_trigger - does view have an INSTEAD OF trigger for event?
+ *
+ * If it does, we don't want to treat it as auto-updatable.  This test can't
+ * be folded into view_query_is_auto_updatable because it's not an error
+ * condition.
+ */
+static bool
+view_has_instead_trigger(Relation view, CmdType event)
+{
+	TriggerDesc *trigDesc = view->trigdesc;
+
+	switch (event)
+	{
+		case CMD_INSERT:
+			if (trigDesc && trigDesc->trig_insert_instead_row)
+				return true;
+			break;
+		case CMD_UPDATE:
+			if (trigDesc && trigDesc->trig_update_instead_row)
+				return true;
+			break;
+		case CMD_DELETE:
+			if (trigDesc && trigDesc->trig_delete_instead_row)
+				return true;
+			break;
+		default:
+			elog(ERROR, "unrecognized CmdType: %d", (int) event);
+			break;
+	}
+	return false;
+}
+
+
+/*
+ * view_col_is_auto_updatable - test whether the specified column of a view
+ * is auto-updatable. Returns NULL (if the column can be updated) or a message
+ * string giving the reason that it cannot be.
+ *
+ * The returned string has not been translated; if it is shown as an error
+ * message, the caller should apply _() to translate it.
+ *
+ * Note that the checks performed here are local to this view. We do not check
+ * whether the referenced column of the underlying base relation is updatable.
+ */
+static const char *
+view_col_is_auto_updatable(RangeTblRef *rtr, TargetEntry *tle)
+{
+	Var		   *var = (Var *) tle->expr;
+
+	/*
+	 * For now, the only updatable columns we support are those that are Vars
+	 * referring to user columns of the underlying base relation.
+	 *
+	 * The view targetlist may contain resjunk columns (e.g., a view defined
+	 * like "SELECT * FROM t ORDER BY a+b" is auto-updatable) but such columns
+	 * are not auto-updatable, and in fact should never appear in the outer
+	 * query's targetlist.
+	 */
+	if (tle->resjunk)
+		return gettext_noop("Junk view columns are not updatable.");
+
+	if (!IsA(var, Var) ||
+		var->varno != rtr->rtindex ||
+		var->varlevelsup != 0)
+		return gettext_noop("View columns that are not columns of their base relation are not updatable.");
+
+	if (var->varattno < 0)
+		return gettext_noop("View columns that refer to system columns are not updatable.");
+
+	if (var->varattno == 0)
+		return gettext_noop("View columns that return whole-row references are not updatable.");
+
+	return NULL;				/* the view column is updatable */
+}
+
+
+/*
+ * view_query_is_auto_updatable - test whether the specified view definition
+ * represents an auto-updatable view. Returns NULL (if the view can be updated)
+ * or a message string giving the reason that it cannot be.
+
+ * The returned string has not been translated; if it is shown as an error
+ * message, the caller should apply _() to translate it.
+ *
+ * If check_cols is true, the view is required to have at least one updatable
+ * column (necessary for INSERT/UPDATE). Otherwise the view's columns are not
+ * checked for updatability. See also view_cols_are_auto_updatable.
+ *
+ * Note that the checks performed here are only based on the view definition.
+ * We do not check whether any base relations referred to by the view are
+ * updatable.
+ */
+const char *
+view_query_is_auto_updatable(Query *viewquery, bool check_cols)
+{
+	RangeTblRef *rtr;
+	RangeTblEntry *base_rte;
+
+	/*----------
+	 * Check if the view is simply updatable.  According to SQL-92 this means:
+	 *	- No DISTINCT clause.
+	 *	- Each TLE is a column reference, and each column appears at most once.
+	 *	- FROM contains exactly one base relation.
+	 *	- No GROUP BY or HAVING clauses.
+	 *	- No set operations (UNION, INTERSECT or EXCEPT).
+	 *	- No sub-queries in the WHERE clause that reference the target table.
+	 *
+	 * We ignore that last restriction since it would be complex to enforce
+	 * and there isn't any actual benefit to disallowing sub-queries.  (The
+	 * semantic issues that the standard is presumably concerned about don't
+	 * arise in Postgres, since any such sub-query will not see any updates
+	 * executed by the outer query anyway, thanks to MVCC snapshotting.)
+	 *
+	 * We also relax the second restriction by supporting part of SQL:1999
+	 * feature T111, which allows for a mix of updatable and non-updatable
+	 * columns, provided that an INSERT or UPDATE doesn't attempt to assign to
+	 * a non-updatable column.
+	 *
+	 * In addition we impose these constraints, involving features that are
+	 * not part of SQL-92:
+	 *	- No CTEs (WITH clauses).
+	 *	- No OFFSET or LIMIT clauses (this matches a SQL:2008 restriction).
+	 *	- No system columns (including whole-row references) in the tlist.
+	 *	- No window functions in the tlist.
+	 *	- No set-returning functions in the tlist.
+	 *
+	 * Note that we do these checks without recursively expanding the view.
+	 * If the base relation is a view, we'll recursively deal with it later.
+	 *----------
+	 */
+	if (viewquery->distinctClause != NIL)
+		return gettext_noop("Views containing DISTINCT are not automatically updatable.");
+
+	if (viewquery->groupClause != NIL || viewquery->groupingSets)
+		return gettext_noop("Views containing GROUP BY are not automatically updatable.");
+
+	if (viewquery->havingQual != NULL)
+		return gettext_noop("Views containing HAVING are not automatically updatable.");
+
+	if (viewquery->setOperations != NULL)
+		return gettext_noop("Views containing UNION, INTERSECT, or EXCEPT are not automatically updatable.");
+
+	if (viewquery->cteList != NIL)
+		return gettext_noop("Views containing WITH are not automatically updatable.");
+
+	if (viewquery->limitOffset != NULL || viewquery->limitCount != NULL)
+		return gettext_noop("Views containing LIMIT or OFFSET are not automatically updatable.");
+
+	/*
+	 * We must not allow window functions or set returning functions in the
+	 * targetlist. Otherwise we might end up inserting them into the quals of
+	 * the main query. We must also check for aggregates in the targetlist in
+	 * case they appear without a GROUP BY.
+	 *
+	 * These restrictions ensure that each row of the view corresponds to a
+	 * unique row in the underlying base relation.
+	 */
+	if (viewquery->hasAggs)
+		return gettext_noop("Views that return aggregate functions are not automatically updatable.");
+
+	if (viewquery->hasWindowFuncs)
+		return gettext_noop("Views that return window functions are not automatically updatable.");
+
+	if (viewquery->hasTargetSRFs)
+		return gettext_noop("Views that return set-returning functions are not automatically updatable.");
+
+	/*
+	 * The view query should select from a single base relation, which must be
+	 * a table or another view.
+	 */
+	if (list_length(viewquery->jointree->fromlist) != 1)
+		return gettext_noop("Views that do not select from a single table or view are not automatically updatable.");
+
+	rtr = (RangeTblRef *) linitial(viewquery->jointree->fromlist);
+	if (!IsA(rtr, RangeTblRef))
+		return gettext_noop("Views that do not select from a single table or view are not automatically updatable.");
+
+	base_rte = rt_fetch(rtr->rtindex, viewquery->rtable);
+	if (base_rte->rtekind != RTE_RELATION ||
+		(base_rte->relkind != RELKIND_RELATION &&
+		 base_rte->relkind != RELKIND_FOREIGN_TABLE &&
+		 base_rte->relkind != RELKIND_VIEW &&
+		 base_rte->relkind != RELKIND_PARTITIONED_TABLE))
+		return gettext_noop("Views that do not select from a single table or view are not automatically updatable.");
+
+	if (base_rte->tablesample)
+		return gettext_noop("Views containing TABLESAMPLE are not automatically updatable.");
+
+	/*
+	 * Check that the view has at least one updatable column. This is required
+	 * for INSERT/UPDATE but not for DELETE.
+	 */
+	if (check_cols)
+	{
+		ListCell   *cell;
+		bool		found;
+
+		found = false;
+		foreach(cell, viewquery->targetList)
+		{
+			TargetEntry *tle = (TargetEntry *) lfirst(cell);
+
+			if (view_col_is_auto_updatable(rtr, tle) == NULL)
+			{
+				found = true;
+				break;
+			}
+		}
+
+		if (!found)
+			return gettext_noop("Views that have no updatable columns are not automatically updatable.");
+	}
+
+	return NULL;				/* the view is updatable */
+}
+
+
+/*
+ * view_cols_are_auto_updatable - test whether all of the required columns of
+ * an auto-updatable view are actually updatable. Returns NULL (if all the
+ * required columns can be updated) or a message string giving the reason that
+ * they cannot be.
+ *
+ * The returned string has not been translated; if it is shown as an error
+ * message, the caller should apply _() to translate it.
+ *
+ * This should be used for INSERT/UPDATE to ensure that we don't attempt to
+ * assign to any non-updatable columns.
+ *
+ * Additionally it may be used to retrieve the set of updatable columns in the
+ * view, or if one or more of the required columns is not updatable, the name
+ * of the first offending non-updatable column.
+ *
+ * The caller must have already verified that this is an auto-updatable view
+ * using view_query_is_auto_updatable.
+ *
+ * Note that the checks performed here are only based on the view definition.
+ * We do not check whether the referenced columns of the base relation are
+ * updatable.
+ */
+static const char *
+view_cols_are_auto_updatable(Query *viewquery,
+							 Bitmapset *required_cols,
+							 Bitmapset **updatable_cols,
+							 char **non_updatable_col)
+{
+	RangeTblRef *rtr;
+	AttrNumber	col;
+	ListCell   *cell;
+
+	/*
+	 * The caller should have verified that this view is auto-updatable and so
+	 * there should be a single base relation.
+	 */
+	Assert(list_length(viewquery->jointree->fromlist) == 1);
+	rtr = linitial_node(RangeTblRef, viewquery->jointree->fromlist);
+
+	/* Initialize the optional return values */
+	if (updatable_cols != NULL)
+		*updatable_cols = NULL;
+	if (non_updatable_col != NULL)
+		*non_updatable_col = NULL;
+
+	/* Test each view column for updatability */
+	col = -FirstLowInvalidHeapAttributeNumber;
+	foreach(cell, viewquery->targetList)
+	{
+		TargetEntry *tle = (TargetEntry *) lfirst(cell);
+		const char *col_update_detail;
+
+		col++;
+		col_update_detail = view_col_is_auto_updatable(rtr, tle);
+
+		if (col_update_detail == NULL)
+		{
+			/* The column is updatable */
+			if (updatable_cols != NULL)
+				*updatable_cols = bms_add_member(*updatable_cols, col);
+		}
+		else if (bms_is_member(col, required_cols))
+		{
+			/* The required column is not updatable */
+			if (non_updatable_col != NULL)
+				*non_updatable_col = tle->resname;
+			return col_update_detail;
+		}
+	}
+
+	return NULL;				/* all the required view columns are updatable */
+}
+
+
+/*
+ * relation_is_updatable - determine which update events the specified
+ * relation supports.
+ *
+ * Note that views may contain a mix of updatable and non-updatable columns.
+ * For a view to support INSERT/UPDATE it must have at least one updatable
+ * column, but there is no such restriction for DELETE. If include_cols is
+ * non-NULL, then only the specified columns are considered when testing for
+ * updatability.
+ *
+ * Unlike the preceding functions, this does recurse to look at a view's
+ * base relations, so it needs to detect recursion.  To do that, we pass
+ * a list of currently-considered outer relations.  External callers need
+ * only pass NIL.
+ *
+ * This is used for the information_schema views, which have separate concepts
+ * of "updatable" and "trigger updatable".  A relation is "updatable" if it
+ * can be updated without the need for triggers (either because it has a
+ * suitable RULE, or because it is simple enough to be automatically updated).
+ * A relation is "trigger updatable" if it has a suitable INSTEAD OF trigger.
+ * The SQL standard regards this as not necessarily updatable, presumably
+ * because there is no way of knowing what the trigger will actually do.
+ * The information_schema views therefore call this function with
+ * include_triggers = false.  However, other callers might only care whether
+ * data-modifying SQL will work, so they can pass include_triggers = true
+ * to have trigger updatability included in the result.
+ *
+ * The return value is a bitmask of rule event numbers indicating which of
+ * the INSERT, UPDATE and DELETE operations are supported.  (We do it this way
+ * so that we can test for UPDATE plus DELETE support in a single call.)
+ */
+int
+relation_is_updatable(Oid reloid,
+					  List *outer_reloids,
+					  bool include_triggers,
+					  Bitmapset *include_cols)
+{
+	int			events = 0;
+	Relation	rel;
+	RuleLock   *rulelocks;
+
+#define ALL_EVENTS ((1 << CMD_INSERT) | (1 << CMD_UPDATE) | (1 << CMD_DELETE))
+
+	/* Since this function recurses, it could be driven to stack overflow */
+	check_stack_depth();
+
+	rel = try_relation_open(reloid, AccessShareLock);
+
+	/*
+	 * If the relation doesn't exist, return zero rather than throwing an
+	 * error.  This is helpful since scanning an information_schema view under
+	 * MVCC rules can result in referencing rels that have actually been
+	 * deleted already.
+	 */
+	if (rel == NULL)
+		return 0;
+
+	/* If we detect a recursive view, report that it is not updatable */
+	if (list_member_oid(outer_reloids, RelationGetRelid(rel)))
+	{
+		relation_close(rel, AccessShareLock);
+		return 0;
+	}
+
+	/* If the relation is a table, it is always updatable */
+	if (rel->rd_rel->relkind == RELKIND_RELATION ||
+		rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
+	{
+		relation_close(rel, AccessShareLock);
+		return ALL_EVENTS;
+	}
+
+	/* Look for unconditional DO INSTEAD rules, and note supported events */
+	rulelocks = rel->rd_rules;
+	if (rulelocks != NULL)
+	{
+		int			i;
+
+		for (i = 0; i < rulelocks->numLocks; i++)
+		{
+			if (rulelocks->rules[i]->isInstead &&
+				rulelocks->rules[i]->qual == NULL)
+			{
+				events |= ((1 << rulelocks->rules[i]->event) & ALL_EVENTS);
+			}
+		}
+
+		/* If we have rules for all events, we're done */
+		if (events == ALL_EVENTS)
+		{
+			relation_close(rel, AccessShareLock);
+			return events;
+		}
+	}
+
+	/* Similarly look for INSTEAD OF triggers, if they are to be included */
+	if (include_triggers)
+	{
+		TriggerDesc *trigDesc = rel->trigdesc;
+
+		if (trigDesc)
+		{
+			if (trigDesc->trig_insert_instead_row)
+				events |= (1 << CMD_INSERT);
+			if (trigDesc->trig_update_instead_row)
+				events |= (1 << CMD_UPDATE);
+			if (trigDesc->trig_delete_instead_row)
+				events |= (1 << CMD_DELETE);
+
+			/* If we have triggers for all events, we're done */
+			if (events == ALL_EVENTS)
+			{
+				relation_close(rel, AccessShareLock);
+				return events;
+			}
+		}
+	}
+
+	/* If this is a foreign table, check which update events it supports */
+	if (rel->rd_rel->relkind == RELKIND_FOREIGN_TABLE)
+	{
+		FdwRoutine *fdwroutine = GetFdwRoutineForRelation(rel, false);
+
+		if (fdwroutine->IsForeignRelUpdatable != NULL)
+			events |= fdwroutine->IsForeignRelUpdatable(rel);
+		else
+		{
+			/* Assume presence of executor functions is sufficient */
+			if (fdwroutine->ExecForeignInsert != NULL)
+				events |= (1 << CMD_INSERT);
+			if (fdwroutine->ExecForeignUpdate != NULL)
+				events |= (1 << CMD_UPDATE);
+			if (fdwroutine->ExecForeignDelete != NULL)
+				events |= (1 << CMD_DELETE);
+		}
+
+		relation_close(rel, AccessShareLock);
+		return events;
+	}
+
+	/* Check if this is an automatically updatable view */
+	if (rel->rd_rel->relkind == RELKIND_VIEW)
+	{
+		Query	   *viewquery = get_view_query(rel);
+
+		if (view_query_is_auto_updatable(viewquery, false) == NULL)
+		{
+			Bitmapset  *updatable_cols;
+			int			auto_events;
+			RangeTblRef *rtr;
+			RangeTblEntry *base_rte;
+			Oid			baseoid;
+
+			/*
+			 * Determine which of the view's columns are updatable. If there
+			 * are none within the set of columns we are looking at, then the
+			 * view doesn't support INSERT/UPDATE, but it may still support
+			 * DELETE.
+			 */
+			view_cols_are_auto_updatable(viewquery, NULL,
+										 &updatable_cols, NULL);
+
+			if (include_cols != NULL)
+				updatable_cols = bms_int_members(updatable_cols, include_cols);
+
+			if (bms_is_empty(updatable_cols))
+				auto_events = (1 << CMD_DELETE);	/* May support DELETE */
+			else
+				auto_events = ALL_EVENTS;	/* May support all events */
+
+			/*
+			 * The base relation must also support these update commands.
+			 * Tables are always updatable, but for any other kind of base
+			 * relation we must do a recursive check limited to the columns
+			 * referenced by the locally updatable columns in this view.
+			 */
+			rtr = (RangeTblRef *) linitial(viewquery->jointree->fromlist);
+			base_rte = rt_fetch(rtr->rtindex, viewquery->rtable);
+			Assert(base_rte->rtekind == RTE_RELATION);
+
+			if (base_rte->relkind != RELKIND_RELATION &&
+				base_rte->relkind != RELKIND_PARTITIONED_TABLE)
+			{
+				baseoid = base_rte->relid;
+				outer_reloids = lappend_oid(outer_reloids,
+											RelationGetRelid(rel));
+				include_cols = adjust_view_column_set(updatable_cols,
+													  viewquery->targetList);
+				auto_events &= relation_is_updatable(baseoid,
+													 outer_reloids,
+													 include_triggers,
+													 include_cols);
+				outer_reloids = list_delete_last(outer_reloids);
+			}
+			events |= auto_events;
+		}
+	}
+
+	/* If we reach here, the relation may support some update commands */
+	relation_close(rel, AccessShareLock);
+	return events;
+}
+
+
+/*
+ * adjust_view_column_set - map a set of column numbers according to targetlist
+ *
+ * This is used with simply-updatable views to map column-permissions sets for
+ * the view columns onto the matching columns in the underlying base relation.
+ * The targetlist is expected to be a list of plain Vars of the underlying
+ * relation (as per the checks above in view_query_is_auto_updatable).
+ */
+static Bitmapset *
+adjust_view_column_set(Bitmapset *cols, List *targetlist)
+{
+	Bitmapset  *result = NULL;
+	int			col;
+
+	col = -1;
+	while ((col = bms_next_member(cols, col)) >= 0)
+	{
+		/* bit numbers are offset by FirstLowInvalidHeapAttributeNumber */
+		AttrNumber	attno = col + FirstLowInvalidHeapAttributeNumber;
+
+		if (attno == InvalidAttrNumber)
+		{
+			/*
+			 * There's a whole-row reference to the view.  For permissions
+			 * purposes, treat it as a reference to each column available from
+			 * the view.  (We should *not* convert this to a whole-row
+			 * reference to the base relation, since the view may not touch
+			 * all columns of the base relation.)
+			 */
+			ListCell   *lc;
+
+			foreach(lc, targetlist)
+			{
+				TargetEntry *tle = lfirst_node(TargetEntry, lc);
+				Var		   *var;
+
+				if (tle->resjunk)
+					continue;
+				var = castNode(Var, tle->expr);
+				result = bms_add_member(result,
+										var->varattno - FirstLowInvalidHeapAttributeNumber);
+			}
+		}
+		else
+		{
+			/*
+			 * Views do not have system columns, so we do not expect to see
+			 * any other system attnos here.  If we do find one, the error
+			 * case will apply.
+			 */
+			TargetEntry *tle = get_tle_by_resno(targetlist, attno);
+
+			if (tle != NULL && !tle->resjunk && IsA(tle->expr, Var))
+			{
+				Var		   *var = (Var *) tle->expr;
+
+				result = bms_add_member(result,
+										var->varattno - FirstLowInvalidHeapAttributeNumber);
+			}
+			else
+				elog(ERROR, "attribute number %d not found in view targetlist",
+					 attno);
+		}
+	}
+
+	return result;
+}
+
+
+/*
+ * rewriteTargetView -
+ *	  Attempt to rewrite a query where the target relation is a view, so that
+ *	  the view's base relation becomes the target relation.
+ *
+ * Note that the base relation here may itself be a view, which may or may not
+ * have INSTEAD OF triggers or rules to handle the update.  That is handled by
+ * the recursion in RewriteQuery.
+ */
+static Query *
+rewriteTargetView(Query *parsetree, Relation view)
+{
+	Query	   *viewquery;
+	const char *auto_update_detail;
+	RangeTblRef *rtr;
+	int			base_rt_index;
+	int			new_rt_index;
+	RangeTblEntry *base_rte;
+	RangeTblEntry *view_rte;
+	RangeTblEntry *new_rte;
+	Relation	base_rel;
+	List	   *view_targetlist;
+	ListCell   *lc;
+
+	/*
+	 * Get the Query from the view's ON SELECT rule.  We're going to munge the
+	 * Query to change the view's base relation into the target relation,
+	 * along with various other changes along the way, so we need to make a
+	 * copy of it (get_view_query() returns a pointer into the relcache, so we
+	 * have to treat it as read-only).
+	 */
+	viewquery = copyObject(get_view_query(view));
+
+	/* The view must be updatable, else fail */
+	auto_update_detail =
+		view_query_is_auto_updatable(viewquery,
+									 parsetree->commandType != CMD_DELETE);
+
+	if (auto_update_detail)
+	{
+		/* messages here should match execMain.c's CheckValidResultRel */
+		switch (parsetree->commandType)
+		{
+			case CMD_INSERT:
+				ereport(ERROR,
+						(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+						 errmsg("cannot insert into view \"%s\"",
+								RelationGetRelationName(view)),
+						 errdetail_internal("%s", _(auto_update_detail)),
+						 errhint("To enable inserting into the view, provide an INSTEAD OF INSERT trigger or an unconditional ON INSERT DO INSTEAD rule.")));
+				break;
+			case CMD_UPDATE:
+				ereport(ERROR,
+						(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+						 errmsg("cannot update view \"%s\"",
+								RelationGetRelationName(view)),
+						 errdetail_internal("%s", _(auto_update_detail)),
+						 errhint("To enable updating the view, provide an INSTEAD OF UPDATE trigger or an unconditional ON UPDATE DO INSTEAD rule.")));
+				break;
+			case CMD_DELETE:
+				ereport(ERROR,
+						(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+						 errmsg("cannot delete from view \"%s\"",
+								RelationGetRelationName(view)),
+						 errdetail_internal("%s", _(auto_update_detail)),
+						 errhint("To enable deleting from the view, provide an INSTEAD OF DELETE trigger or an unconditional ON DELETE DO INSTEAD rule.")));
+				break;
+			default:
+				elog(ERROR, "unrecognized CmdType: %d",
+					 (int) parsetree->commandType);
+				break;
+		}
+	}
+
+	/*
+	 * For INSERT/UPDATE the modified columns must all be updatable. Note that
+	 * we get the modified columns from the query's targetlist, not from the
+	 * result RTE's insertedCols and/or updatedCols set, since
+	 * rewriteTargetListIU may have added additional targetlist entries for
+	 * view defaults, and these must also be updatable.
+	 */
+	if (parsetree->commandType != CMD_DELETE)
+	{
+		Bitmapset  *modified_cols = NULL;
+		char	   *non_updatable_col;
+
+		foreach(lc, parsetree->targetList)
+		{
+			TargetEntry *tle = (TargetEntry *) lfirst(lc);
+
+			if (!tle->resjunk)
+				modified_cols = bms_add_member(modified_cols,
+											   tle->resno - FirstLowInvalidHeapAttributeNumber);
+		}
+
+		if (parsetree->onConflict)
+		{
+			foreach(lc, parsetree->onConflict->onConflictSet)
+			{
+				TargetEntry *tle = (TargetEntry *) lfirst(lc);
+
+				if (!tle->resjunk)
+					modified_cols = bms_add_member(modified_cols,
+												   tle->resno - FirstLowInvalidHeapAttributeNumber);
+			}
+		}
+
+		auto_update_detail = view_cols_are_auto_updatable(viewquery,
+														  modified_cols,
+														  NULL,
+														  &non_updatable_col);
+		if (auto_update_detail)
+		{
+			/*
+			 * This is a different error, caused by an attempt to update a
+			 * non-updatable column in an otherwise updatable view.
+			 */
+			switch (parsetree->commandType)
+			{
+				case CMD_INSERT:
+					ereport(ERROR,
+							(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+							 errmsg("cannot insert into column \"%s\" of view \"%s\"",
+									non_updatable_col,
+									RelationGetRelationName(view)),
+							 errdetail_internal("%s", _(auto_update_detail))));
+					break;
+				case CMD_UPDATE:
+					ereport(ERROR,
+							(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+							 errmsg("cannot update column \"%s\" of view \"%s\"",
+									non_updatable_col,
+									RelationGetRelationName(view)),
+							 errdetail_internal("%s", _(auto_update_detail))));
+					break;
+				default:
+					elog(ERROR, "unrecognized CmdType: %d",
+						 (int) parsetree->commandType);
+					break;
+			}
+		}
+	}
+
+	/* Locate RTE describing the view in the outer query */
+	view_rte = rt_fetch(parsetree->resultRelation, parsetree->rtable);
+
+	/*
+	 * If we get here, view_query_is_auto_updatable() has verified that the
+	 * view contains a single base relation.
+	 */
+	Assert(list_length(viewquery->jointree->fromlist) == 1);
+	rtr = linitial_node(RangeTblRef, viewquery->jointree->fromlist);
+
+	base_rt_index = rtr->rtindex;
+	base_rte = rt_fetch(base_rt_index, viewquery->rtable);
+	Assert(base_rte->rtekind == RTE_RELATION);
+
+	/*
+	 * Up to now, the base relation hasn't been touched at all in our query.
+	 * We need to acquire lock on it before we try to do anything with it.
+	 * (The subsequent recursive call of RewriteQuery will suppose that we
+	 * already have the right lock!)  Since it will become the query target
+	 * relation, RowExclusiveLock is always the right thing.
+	 */
+	base_rel = table_open(base_rte->relid, RowExclusiveLock);
+
+	/*
+	 * While we have the relation open, update the RTE's relkind, just in case
+	 * it changed since this view was made (cf. AcquireRewriteLocks).
+	 */
+	base_rte->relkind = base_rel->rd_rel->relkind;
+
+	/*
+	 * If the view query contains any sublink subqueries then we need to also
+	 * acquire locks on any relations they refer to.  We know that there won't
+	 * be any subqueries in the range table or CTEs, so we can skip those, as
+	 * in AcquireRewriteLocks.
+	 */
+	if (viewquery->hasSubLinks)
+	{
+		acquireLocksOnSubLinks_context context;
+
+		context.for_execute = true;
+		query_tree_walker(viewquery, acquireLocksOnSubLinks, &context,
+						  QTW_IGNORE_RC_SUBQUERIES);
+	}
+
+	/*
+	 * Create a new target RTE describing the base relation, and add it to the
+	 * outer query's rangetable.  (What's happening in the next few steps is
+	 * very much like what the planner would do to "pull up" the view into the
+	 * outer query.  Perhaps someday we should refactor things enough so that
+	 * we can share code with the planner.)
+	 *
+	 * Be sure to set rellockmode to the correct thing for the target table.
+	 * Since we copied the whole viewquery above, we can just scribble on
+	 * base_rte instead of copying it.
+	 */
+	new_rte = base_rte;
+	new_rte->rellockmode = RowExclusiveLock;
+
+	parsetree->rtable = lappend(parsetree->rtable, new_rte);
+	new_rt_index = list_length(parsetree->rtable);
+
+	/*
+	 * INSERTs never inherit.  For UPDATE/DELETE, we use the view query's
+	 * inheritance flag for the base relation.
+	 */
+	if (parsetree->commandType == CMD_INSERT)
+		new_rte->inh = false;
+
+	/*
+	 * Adjust the view's targetlist Vars to reference the new target RTE, ie
+	 * make their varnos be new_rt_index instead of base_rt_index.  There can
+	 * be no Vars for other rels in the tlist, so this is sufficient to pull
+	 * up the tlist expressions for use in the outer query.  The tlist will
+	 * provide the replacement expressions used by ReplaceVarsFromTargetList
+	 * below.
+	 */
+	view_targetlist = viewquery->targetList;
+
+	ChangeVarNodes((Node *) view_targetlist,
+				   base_rt_index,
+				   new_rt_index,
+				   0);
+
+	/*
+	 * Mark the new target RTE for the permissions checks that we want to
+	 * enforce against the view owner, as distinct from the query caller.  At
+	 * the relation level, require the same INSERT/UPDATE/DELETE permissions
+	 * that the query caller needs against the view.  We drop the ACL_SELECT
+	 * bit that is presumably in new_rte->requiredPerms initially.
+	 *
+	 * Note: the original view RTE remains in the query's rangetable list.
+	 * Although it will be unused in the query plan, we need it there so that
+	 * the executor still performs appropriate permissions checks for the
+	 * query caller's use of the view.
+	 */
+	new_rte->checkAsUser = view->rd_rel->relowner;
+	new_rte->requiredPerms = view_rte->requiredPerms;
+
+	/*
+	 * Now for the per-column permissions bits.
+	 *
+	 * Initially, new_rte contains selectedCols permission check bits for all
+	 * base-rel columns referenced by the view, but since the view is a SELECT
+	 * query its insertedCols/updatedCols is empty.  We set insertedCols and
+	 * updatedCols to include all the columns the outer query is trying to
+	 * modify, adjusting the column numbers as needed.  But we leave
+	 * selectedCols as-is, so the view owner must have read permission for all
+	 * columns used in the view definition, even if some of them are not read
+	 * by the outer query.  We could try to limit selectedCols to only columns
+	 * used in the transformed query, but that does not correspond to what
+	 * happens in ordinary SELECT usage of a view: all referenced columns must
+	 * have read permission, even if optimization finds that some of them can
+	 * be discarded during query transformation.  The flattening we're doing
+	 * here is an optional optimization, too.  (If you are unpersuaded and
+	 * want to change this, note that applying adjust_view_column_set to
+	 * view_rte->selectedCols is clearly *not* the right answer, since that
+	 * neglects base-rel columns used in the view's WHERE quals.)
+	 *
+	 * This step needs the modified view targetlist, so we have to do things
+	 * in this order.
+	 */
+	Assert(bms_is_empty(new_rte->insertedCols) &&
+		   bms_is_empty(new_rte->updatedCols));
+
+	new_rte->insertedCols = adjust_view_column_set(view_rte->insertedCols,
+												   view_targetlist);
+
+	new_rte->updatedCols = adjust_view_column_set(view_rte->updatedCols,
+												  view_targetlist);
+
+	/*
+	 * Move any security barrier quals from the view RTE onto the new target
+	 * RTE.  Any such quals should now apply to the new target RTE and will
+	 * not reference the original view RTE in the rewritten query.
+	 */
+	new_rte->securityQuals = view_rte->securityQuals;
+	view_rte->securityQuals = NIL;
+
+	/*
+	 * Now update all Vars in the outer query that reference the view to
+	 * reference the appropriate column of the base relation instead.
+	 */
+	parsetree = (Query *)
+		ReplaceVarsFromTargetList((Node *) parsetree,
+								  parsetree->resultRelation,
+								  0,
+								  view_rte,
+								  view_targetlist,
+								  REPLACEVARS_REPORT_ERROR,
+								  0,
+								  &parsetree->hasSubLinks);
+
+	/*
+	 * Update all other RTI references in the query that point to the view
+	 * (for example, parsetree->resultRelation itself) to point to the new
+	 * base relation instead.  Vars will not be affected since none of them
+	 * reference parsetree->resultRelation any longer.
+	 */
+	ChangeVarNodes((Node *) parsetree,
+				   parsetree->resultRelation,
+				   new_rt_index,
+				   0);
+	Assert(parsetree->resultRelation == new_rt_index);
+
+	/*
+	 * For INSERT/UPDATE we must also update resnos in the targetlist to refer
+	 * to columns of the base relation, since those indicate the target
+	 * columns to be affected.
+	 *
+	 * Note that this destroys the resno ordering of the targetlist, but that
+	 * will be fixed when we recurse through rewriteQuery, which will invoke
+	 * rewriteTargetListIU again on the updated targetlist.
+	 */
+	if (parsetree->commandType != CMD_DELETE)
+	{
+		foreach(lc, parsetree->targetList)
+		{
+			TargetEntry *tle = (TargetEntry *) lfirst(lc);
+			TargetEntry *view_tle;
+
+			if (tle->resjunk)
+				continue;
+
+			view_tle = get_tle_by_resno(view_targetlist, tle->resno);
+			if (view_tle != NULL && !view_tle->resjunk && IsA(view_tle->expr, Var))
+				tle->resno = ((Var *) view_tle->expr)->varattno;
+			else
+				elog(ERROR, "attribute number %d not found in view targetlist",
+					 tle->resno);
+		}
+	}
+
+	/*
+	 * For INSERT .. ON CONFLICT .. DO UPDATE, we must also update assorted
+	 * stuff in the onConflict data structure.
+	 */
+	if (parsetree->onConflict &&
+		parsetree->onConflict->action == ONCONFLICT_UPDATE)
+	{
+		Index		old_exclRelIndex,
+					new_exclRelIndex;
+		ParseNamespaceItem *new_exclNSItem;
+		RangeTblEntry *new_exclRte;
+		List	   *tmp_tlist;
+
+		/*
+		 * Like the INSERT/UPDATE code above, update the resnos in the
+		 * auxiliary UPDATE targetlist to refer to columns of the base
+		 * relation.
+		 */
+		foreach(lc, parsetree->onConflict->onConflictSet)
+		{
+			TargetEntry *tle = (TargetEntry *) lfirst(lc);
+			TargetEntry *view_tle;
+
+			if (tle->resjunk)
+				continue;
+
+			view_tle = get_tle_by_resno(view_targetlist, tle->resno);
+			if (view_tle != NULL && !view_tle->resjunk && IsA(view_tle->expr, Var))
+				tle->resno = ((Var *) view_tle->expr)->varattno;
+			else
+				elog(ERROR, "attribute number %d not found in view targetlist",
+					 tle->resno);
+		}
+
+		/*
+		 * Also, create a new RTE for the EXCLUDED pseudo-relation, using the
+		 * query's new base rel (which may well have a different column list
+		 * from the view, hence we need a new column alias list).  This should
+		 * match transformOnConflictClause.  In particular, note that the
+		 * relkind is set to composite to signal that we're not dealing with
+		 * an actual relation, and no permissions checks are wanted.
+		 */
+		old_exclRelIndex = parsetree->onConflict->exclRelIndex;
+
+		new_exclNSItem = addRangeTableEntryForRelation(make_parsestate(NULL),
+													   base_rel,
+													   RowExclusiveLock,
+													   makeAlias("excluded", NIL),
+													   false, false);
+		new_exclRte = new_exclNSItem->p_rte;
+		new_exclRte->relkind = RELKIND_COMPOSITE_TYPE;
+		new_exclRte->requiredPerms = 0;
+		/* other permissions fields in new_exclRte are already empty */
+
+		parsetree->rtable = lappend(parsetree->rtable, new_exclRte);
+		new_exclRelIndex = parsetree->onConflict->exclRelIndex =
+			list_length(parsetree->rtable);
+
+		/*
+		 * Replace the targetlist for the EXCLUDED pseudo-relation with a new
+		 * one, representing the columns from the new base relation.
+		 */
+		parsetree->onConflict->exclRelTlist =
+			BuildOnConflictExcludedTargetlist(base_rel, new_exclRelIndex);
+
+		/*
+		 * Update all Vars in the ON CONFLICT clause that refer to the old
+		 * EXCLUDED pseudo-relation.  We want to use the column mappings
+		 * defined in the view targetlist, but we need the outputs to refer to
+		 * the new EXCLUDED pseudo-relation rather than the new target RTE.
+		 * Also notice that "EXCLUDED.*" will be expanded using the view's
+		 * rowtype, which seems correct.
+		 */
+		tmp_tlist = copyObject(view_targetlist);
+
+		ChangeVarNodes((Node *) tmp_tlist, new_rt_index,
+					   new_exclRelIndex, 0);
+
+		parsetree->onConflict = (OnConflictExpr *)
+			ReplaceVarsFromTargetList((Node *) parsetree->onConflict,
+									  old_exclRelIndex,
+									  0,
+									  view_rte,
+									  tmp_tlist,
+									  REPLACEVARS_REPORT_ERROR,
+									  0,
+									  &parsetree->hasSubLinks);
+	}
+
+	/*
+	 * For UPDATE/DELETE, pull up any WHERE quals from the view.  We know that
+	 * any Vars in the quals must reference the one base relation, so we need
+	 * only adjust their varnos to reference the new target (just the same as
+	 * we did with the view targetlist).
+	 *
+	 * If it's a security-barrier view, its WHERE quals must be applied before
+	 * quals from the outer query, so we attach them to the RTE as security
+	 * barrier quals rather than adding them to the main WHERE clause.
+	 *
+	 * For INSERT, the view's quals can be ignored in the main query.
+	 */
+	if (parsetree->commandType != CMD_INSERT &&
+		viewquery->jointree->quals != NULL)
+	{
+		Node	   *viewqual = (Node *) viewquery->jointree->quals;
+
+		/*
+		 * Even though we copied viewquery already at the top of this
+		 * function, we must duplicate the viewqual again here, because we may
+		 * need to use the quals again below for a WithCheckOption clause.
+		 */
+		viewqual = copyObject(viewqual);
+
+		ChangeVarNodes(viewqual, base_rt_index, new_rt_index, 0);
+
+		if (RelationIsSecurityView(view))
+		{
+			/*
+			 * The view's quals go in front of existing barrier quals: those
+			 * would have come from an outer level of security-barrier view,
+			 * and so must get evaluated later.
+			 *
+			 * Note: the parsetree has been mutated, so the new_rte pointer is
+			 * stale and needs to be re-computed.
+			 */
+			new_rte = rt_fetch(new_rt_index, parsetree->rtable);
+			new_rte->securityQuals = lcons(viewqual, new_rte->securityQuals);
+
+			/*
+			 * Do not set parsetree->hasRowSecurity, because these aren't RLS
+			 * conditions (they aren't affected by enabling/disabling RLS).
+			 */
+
+			/*
+			 * Make sure that the query is marked correctly if the added qual
+			 * has sublinks.
+			 */
+			if (!parsetree->hasSubLinks)
+				parsetree->hasSubLinks = checkExprHasSubLink(viewqual);
+		}
+		else
+			AddQual(parsetree, (Node *) viewqual);
+	}
+
+	/*
+	 * For INSERT/UPDATE, if the view has the WITH CHECK OPTION, or any parent
+	 * view specified WITH CASCADED CHECK OPTION, add the quals from the view
+	 * to the query's withCheckOptions list.
+	 */
+	if (parsetree->commandType != CMD_DELETE)
+	{
+		bool		has_wco = RelationHasCheckOption(view);
+		bool		cascaded = RelationHasCascadedCheckOption(view);
+
+		/*
+		 * If the parent view has a cascaded check option, treat this view as
+		 * if it also had a cascaded check option.
+		 *
+		 * New WithCheckOptions are added to the start of the list, so if
+		 * there is a cascaded check option, it will be the first item in the
+		 * list.
+		 */
+		if (parsetree->withCheckOptions != NIL)
+		{
+			WithCheckOption *parent_wco =
+			(WithCheckOption *) linitial(parsetree->withCheckOptions);
+
+			if (parent_wco->cascaded)
+			{
+				has_wco = true;
+				cascaded = true;
+			}
+		}
+
+		/*
+		 * Add the new WithCheckOption to the start of the list, so that
+		 * checks on inner views are run before checks on outer views, as
+		 * required by the SQL standard.
+		 *
+		 * If the new check is CASCADED, we need to add it even if this view
+		 * has no quals, since there may be quals on child views.  A LOCAL
+		 * check can be omitted if this view has no quals.
+		 */
+		if (has_wco && (cascaded || viewquery->jointree->quals != NULL))
+		{
+			WithCheckOption *wco;
+
+			wco = makeNode(WithCheckOption);
+			wco->kind = WCO_VIEW_CHECK;
+			wco->relname = pstrdup(RelationGetRelationName(view));
+			wco->polname = NULL;
+			wco->qual = NULL;
+			wco->cascaded = cascaded;
+
+			parsetree->withCheckOptions = lcons(wco,
+												parsetree->withCheckOptions);
+
+			if (viewquery->jointree->quals != NULL)
+			{
+				wco->qual = (Node *) viewquery->jointree->quals;
+				ChangeVarNodes(wco->qual, base_rt_index, new_rt_index, 0);
+
+				/*
+				 * Make sure that the query is marked correctly if the added
+				 * qual has sublinks.  We can skip this check if the query is
+				 * already marked, or if the command is an UPDATE, in which
+				 * case the same qual will have already been added, and this
+				 * check will already have been done.
+				 */
+				if (!parsetree->hasSubLinks &&
+					parsetree->commandType != CMD_UPDATE)
+					parsetree->hasSubLinks = checkExprHasSubLink(wco->qual);
+			}
+		}
+	}
+
+	table_close(base_rel, NoLock);
+
+	return parsetree;
+}
+
+
+/*
+ * RewriteQuery -
+ *	  rewrites the query and apply the rules again on the queries rewritten
+ *
+ * rewrite_events is a list of open query-rewrite actions, so we can detect
+ * infinite recursion.
+ */
+static List *
+RewriteQuery(Query *parsetree, List *rewrite_events)
+{
+	CmdType		event = parsetree->commandType;
+	bool		instead = false;
+	bool		returning = false;
+	bool		updatableview = false;
+	Query	   *qual_product = NULL;
+	List	   *rewritten = NIL;
+	ListCell   *lc1;
+
+	/*
+	 * First, recursively process any insert/update/delete statements in WITH
+	 * clauses.  (We have to do this first because the WITH clauses may get
+	 * copied into rule actions below.)
+	 */
+	foreach(lc1, parsetree->cteList)
+	{
+		CommonTableExpr *cte = lfirst_node(CommonTableExpr, lc1);
+		Query	   *ctequery = castNode(Query, cte->ctequery);
+		List	   *newstuff;
+
+		if (ctequery->commandType == CMD_SELECT)
+			continue;
+
+		newstuff = RewriteQuery(ctequery, rewrite_events);
+
+		/*
+		 * Currently we can only handle unconditional, single-statement DO
+		 * INSTEAD rules correctly; we have to get exactly one non-utility
+		 * Query out of the rewrite operation to stuff back into the CTE node.
+		 */
+		if (list_length(newstuff) == 1)
+		{
+			/* Must check it's not a utility command */
+			ctequery = linitial_node(Query, newstuff);
+			if (!(ctequery->commandType == CMD_SELECT ||
+				  ctequery->commandType == CMD_UPDATE ||
+				  ctequery->commandType == CMD_INSERT ||
+				  ctequery->commandType == CMD_DELETE))
+			{
+				/*
+				 * Currently it could only be NOTIFY; this error message will
+				 * need work if we ever allow other utility commands in rules.
+				 */
+				ereport(ERROR,
+						(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+						 errmsg("DO INSTEAD NOTIFY rules are not supported for data-modifying statements in WITH")));
+			}
+			/* WITH queries should never be canSetTag */
+			Assert(!ctequery->canSetTag);
+			/* Push the single Query back into the CTE node */
+			cte->ctequery = (Node *) ctequery;
+		}
+		else if (newstuff == NIL)
+		{
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("DO INSTEAD NOTHING rules are not supported for data-modifying statements in WITH")));
+		}
+		else
+		{
+			ListCell   *lc2;
+
+			/* examine queries to determine which error message to issue */
+			foreach(lc2, newstuff)
+			{
+				Query	   *q = (Query *) lfirst(lc2);
+
+				if (q->querySource == QSRC_QUAL_INSTEAD_RULE)
+					ereport(ERROR,
+							(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+							 errmsg("conditional DO INSTEAD rules are not supported for data-modifying statements in WITH")));
+				if (q->querySource == QSRC_NON_INSTEAD_RULE)
+					ereport(ERROR,
+							(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+							 errmsg("DO ALSO rules are not supported for data-modifying statements in WITH")));
+			}
+
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("multi-statement DO INSTEAD rules are not supported for data-modifying statements in WITH")));
+		}
+	}
+
+	/*
+	 * If the statement is an insert, update, or delete, adjust its targetlist
+	 * as needed, and then fire INSERT/UPDATE/DELETE rules on it.
+	 *
+	 * SELECT rules are handled later when we have all the queries that should
+	 * get executed.  Also, utilities aren't rewritten at all (do we still
+	 * need that check?)
+	 */
+	if (event != CMD_SELECT && event != CMD_UTILITY)
+	{
+		int			result_relation;
+		RangeTblEntry *rt_entry;
+		Relation	rt_entry_relation;
+		List	   *locks;
+		List	   *product_queries;
+		bool		hasUpdate = false;
+		int			values_rte_index = 0;
+		bool		defaults_remaining = false;
+
+		result_relation = parsetree->resultRelation;
+		Assert(result_relation != 0);
+		rt_entry = rt_fetch(result_relation, parsetree->rtable);
+		Assert(rt_entry->rtekind == RTE_RELATION);
+
+		/*
+		 * We can use NoLock here since either the parser or
+		 * AcquireRewriteLocks should have locked the rel already.
+		 */
+		rt_entry_relation = table_open(rt_entry->relid, NoLock);
+
+		/*
+		 * Rewrite the targetlist as needed for the command type.
+		 */
+		if (event == CMD_INSERT)
+		{
+			RangeTblEntry *values_rte = NULL;
+
+			/*
+			 * If it's an INSERT ... VALUES (...), (...), ... there will be a
+			 * single RTE for the VALUES targetlists.
+			 */
+			if (list_length(parsetree->jointree->fromlist) == 1)
+			{
+				RangeTblRef *rtr = (RangeTblRef *) linitial(parsetree->jointree->fromlist);
+
+				if (IsA(rtr, RangeTblRef))
+				{
+					RangeTblEntry *rte = rt_fetch(rtr->rtindex,
+												  parsetree->rtable);
+
+					if (rte->rtekind == RTE_VALUES)
+					{
+						values_rte = rte;
+						values_rte_index = rtr->rtindex;
+					}
+				}
+			}
+
+			if (values_rte)
+			{
+				Bitmapset  *unused_values_attrnos = NULL;
+
+				/* Process the main targetlist ... */
+				parsetree->targetList = rewriteTargetListIU(parsetree->targetList,
+															parsetree->commandType,
+															parsetree->override,
+															rt_entry_relation,
+															values_rte,
+															values_rte_index,
+															&unused_values_attrnos);
+				/* ... and the VALUES expression lists */
+				if (!rewriteValuesRTE(parsetree, values_rte, values_rte_index,
+									  rt_entry_relation, false,
+									  unused_values_attrnos))
+					defaults_remaining = true;
+			}
+			else
+			{
+				/* Process just the main targetlist */
+				parsetree->targetList =
+					rewriteTargetListIU(parsetree->targetList,
+										parsetree->commandType,
+										parsetree->override,
+										rt_entry_relation,
+										NULL, 0, NULL);
+			}
+
+			if (parsetree->onConflict &&
+				parsetree->onConflict->action == ONCONFLICT_UPDATE)
+			{
+				parsetree->onConflict->onConflictSet =
+					rewriteTargetListIU(parsetree->onConflict->onConflictSet,
+										CMD_UPDATE,
+										parsetree->override,
+										rt_entry_relation,
+										NULL, 0, NULL);
+			}
+		}
+		else if (event == CMD_UPDATE)
+		{
+			parsetree->targetList =
+				rewriteTargetListIU(parsetree->targetList,
+									parsetree->commandType,
+									parsetree->override,
+									rt_entry_relation,
+									NULL, 0, NULL);
+
+			/* Also populate extraUpdatedCols (for generated columns) */
+			fill_extraUpdatedCols(rt_entry, rt_entry_relation);
+		}
+		else if (event == CMD_DELETE)
+		{
+			/* Nothing to do here */
+		}
+		else
+			elog(ERROR, "unrecognized commandType: %d", (int) event);
+
+		/*
+		 * Collect and apply the appropriate rules.
+		 */
+		locks = matchLocks(event, rt_entry_relation->rd_rules,
+						   result_relation, parsetree, &hasUpdate);
+
+		product_queries = fireRules(parsetree,
+									result_relation,
+									event,
+									locks,
+									&instead,
+									&returning,
+									&qual_product);
+
+		/*
+		 * If we have a VALUES RTE with any remaining untouched DEFAULT items,
+		 * and we got any product queries, finalize the VALUES RTE for each
+		 * product query (replacing the remaining DEFAULT items with NULLs).
+		 * We don't do this for the original query, because we know that it
+		 * must be an auto-insert on a view, and so should use the base
+		 * relation's defaults for any remaining DEFAULT items.
+		 */
+		if (defaults_remaining && product_queries != NIL)
+		{
+			ListCell   *n;
+
+			/*
+			 * Each product query has its own copy of the VALUES RTE at the
+			 * same index in the rangetable, so we must finalize each one.
+			 */
+			foreach(n, product_queries)
+			{
+				Query	   *pt = (Query *) lfirst(n);
+				RangeTblEntry *values_rte = rt_fetch(values_rte_index,
+													 pt->rtable);
+
+				rewriteValuesRTE(pt, values_rte, values_rte_index,
+								 rt_entry_relation,
+								 true,	/* Force remaining defaults to NULL */
+								 NULL);
+			}
+		}
+
+		/*
+		 * If there was no unqualified INSTEAD rule, and the target relation
+		 * is a view without any INSTEAD OF triggers, see if the view can be
+		 * automatically updated.  If so, we perform the necessary query
+		 * transformation here and add the resulting query to the
+		 * product_queries list, so that it gets recursively rewritten if
+		 * necessary.
+		 *
+		 * If the view cannot be automatically updated, we throw an error here
+		 * which is OK since the query would fail at runtime anyway.  Throwing
+		 * the error here is preferable to the executor check since we have
+		 * more detailed information available about why the view isn't
+		 * updatable.
+		 */
+		if (!instead &&
+			rt_entry_relation->rd_rel->relkind == RELKIND_VIEW &&
+			!view_has_instead_trigger(rt_entry_relation, event))
+		{
+			/*
+			 * If there were any qualified INSTEAD rules, don't allow the view
+			 * to be automatically updated (an unqualified INSTEAD rule or
+			 * INSTEAD OF trigger is required).
+			 *
+			 * The messages here should match execMain.c's CheckValidResultRel
+			 * and in principle make those checks in executor unnecessary, but
+			 * we keep them just in case.
+			 */
+			if (qual_product != NULL)
+			{
+				switch (parsetree->commandType)
+				{
+					case CMD_INSERT:
+						ereport(ERROR,
+								(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+								 errmsg("cannot insert into view \"%s\"",
+										RelationGetRelationName(rt_entry_relation)),
+								 errdetail("Views with conditional DO INSTEAD rules are not automatically updatable."),
+								 errhint("To enable inserting into the view, provide an INSTEAD OF INSERT trigger or an unconditional ON INSERT DO INSTEAD rule.")));
+						break;
+					case CMD_UPDATE:
+						ereport(ERROR,
+								(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+								 errmsg("cannot update view \"%s\"",
+										RelationGetRelationName(rt_entry_relation)),
+								 errdetail("Views with conditional DO INSTEAD rules are not automatically updatable."),
+								 errhint("To enable updating the view, provide an INSTEAD OF UPDATE trigger or an unconditional ON UPDATE DO INSTEAD rule.")));
+						break;
+					case CMD_DELETE:
+						ereport(ERROR,
+								(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+								 errmsg("cannot delete from view \"%s\"",
+										RelationGetRelationName(rt_entry_relation)),
+								 errdetail("Views with conditional DO INSTEAD rules are not automatically updatable."),
+								 errhint("To enable deleting from the view, provide an INSTEAD OF DELETE trigger or an unconditional ON DELETE DO INSTEAD rule.")));
+						break;
+					default:
+						elog(ERROR, "unrecognized CmdType: %d",
+							 (int) parsetree->commandType);
+						break;
+				}
+			}
+
+			/*
+			 * Attempt to rewrite the query to automatically update the view.
+			 * This throws an error if the view can't be automatically
+			 * updated.
+			 */
+			parsetree = rewriteTargetView(parsetree, rt_entry_relation);
+
+			/*
+			 * At this point product_queries contains any DO ALSO rule
+			 * actions. Add the rewritten query before or after those.  This
+			 * must match the handling the original query would have gotten
+			 * below, if we allowed it to be included again.
+			 */
+			if (parsetree->commandType == CMD_INSERT)
+				product_queries = lcons(parsetree, product_queries);
+			else
+				product_queries = lappend(product_queries, parsetree);
+
+			/*
+			 * Set the "instead" flag, as if there had been an unqualified
+			 * INSTEAD, to prevent the original query from being included a
+			 * second time below.  The transformation will have rewritten any
+			 * RETURNING list, so we can also set "returning" to forestall
+			 * throwing an error below.
+			 */
+			instead = true;
+			returning = true;
+			updatableview = true;
+		}
+
+		/*
+		 * If we got any product queries, recursively rewrite them --- but
+		 * first check for recursion!
+		 */
+		if (product_queries != NIL)
+		{
+			ListCell   *n;
+			rewrite_event *rev;
+
+			foreach(n, rewrite_events)
+			{
+				rev = (rewrite_event *) lfirst(n);
+				if (rev->relation == RelationGetRelid(rt_entry_relation) &&
+					rev->event == event)
+					ereport(ERROR,
+							(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
+							 errmsg("infinite recursion detected in rules for relation \"%s\"",
+									RelationGetRelationName(rt_entry_relation))));
+			}
+
+			rev = (rewrite_event *) palloc(sizeof(rewrite_event));
+			rev->relation = RelationGetRelid(rt_entry_relation);
+			rev->event = event;
+			rewrite_events = lappend(rewrite_events, rev);
+
+			foreach(n, product_queries)
+			{
+				Query	   *pt = (Query *) lfirst(n);
+				List	   *newstuff;
+
+				newstuff = RewriteQuery(pt, rewrite_events);
+				rewritten = list_concat(rewritten, newstuff);
+			}
+
+			rewrite_events = list_delete_last(rewrite_events);
+		}
+
+		/*
+		 * If there is an INSTEAD, and the original query has a RETURNING, we
+		 * have to have found a RETURNING in the rule(s), else fail. (Because
+		 * DefineQueryRewrite only allows RETURNING in unconditional INSTEAD
+		 * rules, there's no need to worry whether the substituted RETURNING
+		 * will actually be executed --- it must be.)
+		 */
+		if ((instead || qual_product != NULL) &&
+			parsetree->returningList &&
+			!returning)
+		{
+			switch (event)
+			{
+				case CMD_INSERT:
+					ereport(ERROR,
+							(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+							 errmsg("cannot perform INSERT RETURNING on relation \"%s\"",
+									RelationGetRelationName(rt_entry_relation)),
+							 errhint("You need an unconditional ON INSERT DO INSTEAD rule with a RETURNING clause.")));
+					break;
+				case CMD_UPDATE:
+					ereport(ERROR,
+							(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+							 errmsg("cannot perform UPDATE RETURNING on relation \"%s\"",
+									RelationGetRelationName(rt_entry_relation)),
+							 errhint("You need an unconditional ON UPDATE DO INSTEAD rule with a RETURNING clause.")));
+					break;
+				case CMD_DELETE:
+					ereport(ERROR,
+							(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+							 errmsg("cannot perform DELETE RETURNING on relation \"%s\"",
+									RelationGetRelationName(rt_entry_relation)),
+							 errhint("You need an unconditional ON DELETE DO INSTEAD rule with a RETURNING clause.")));
+					break;
+				default:
+					elog(ERROR, "unrecognized commandType: %d",
+						 (int) event);
+					break;
+			}
+		}
+
+		/*
+		 * Updatable views are supported by ON CONFLICT, so don't prevent that
+		 * case from proceeding
+		 */
+		if (parsetree->onConflict &&
+			(product_queries != NIL || hasUpdate) &&
+			!updatableview)
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("INSERT with ON CONFLICT clause cannot be used with table that has INSERT or UPDATE rules")));
+
+		table_close(rt_entry_relation, NoLock);
+	}
+
+	/*
+	 * For INSERTs, the original query is done first; for UPDATE/DELETE, it is
+	 * done last.  This is needed because update and delete rule actions might
+	 * not do anything if they are invoked after the update or delete is
+	 * performed. The command counter increment between the query executions
+	 * makes the deleted (and maybe the updated) tuples disappear so the scans
+	 * for them in the rule actions cannot find them.
+	 *
+	 * If we found any unqualified INSTEAD, the original query is not done at
+	 * all, in any form.  Otherwise, we add the modified form if qualified
+	 * INSTEADs were found, else the unmodified form.
+	 */
+	if (!instead)
+	{
+		if (parsetree->commandType == CMD_INSERT)
+		{
+			if (qual_product != NULL)
+				rewritten = lcons(qual_product, rewritten);
+			else
+				rewritten = lcons(parsetree, rewritten);
+		}
+		else
+		{
+			if (qual_product != NULL)
+				rewritten = lappend(rewritten, qual_product);
+			else
+				rewritten = lappend(rewritten, parsetree);
+		}
+	}
+
+	/*
+	 * If the original query has a CTE list, and we generated more than one
+	 * non-utility result query, we have to fail because we'll have copied the
+	 * CTE list into each result query.  That would break the expectation of
+	 * single evaluation of CTEs.  This could possibly be fixed by
+	 * restructuring so that a CTE list can be shared across multiple Query
+	 * and PlannableStatement nodes.
+	 */
+	if (parsetree->cteList != NIL)
+	{
+		int			qcount = 0;
+
+		foreach(lc1, rewritten)
+		{
+			Query	   *q = (Query *) lfirst(lc1);
+
+			if (q->commandType != CMD_UTILITY)
+				qcount++;
+		}
+		if (qcount > 1)
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("WITH cannot be used in a query that is rewritten by rules into multiple queries")));
+	}
+
+	return rewritten;
+}
+
+
+/*
+ * QueryRewrite -
+ *	  Primary entry point to the query rewriter.
+ *	  Rewrite one query via query rewrite system, possibly returning 0
+ *	  or many queries.
+ *
+ * NOTE: the parsetree must either have come straight from the parser,
+ * or have been scanned by AcquireRewriteLocks to acquire suitable locks.
+ */
+List *
+QueryRewrite(Query *parsetree)
+{
+	uint64		input_query_id = parsetree->queryId;
+	List	   *querylist;
+	List	   *results;
+	ListCell   *l;
+	CmdType		origCmdType;
+	bool		foundOriginalQuery;
+	Query	   *lastInstead;
+
+	/*
+	 * This function is only applied to top-level original queries
+	 */
+	Assert(parsetree->querySource == QSRC_ORIGINAL);
+	Assert(parsetree->canSetTag);
+
+	/*
+	 * Step 1
+	 *
+	 * Apply all non-SELECT rules possibly getting 0 or many queries
+	 */
+	querylist = RewriteQuery(parsetree, NIL);
+
+	/*
+	 * Step 2
+	 *
+	 * Apply all the RIR rules on each query
+	 *
+	 * This is also a handy place to mark each query with the original queryId
+	 */
+	results = NIL;
+	foreach(l, querylist)
+	{
+		Query	   *query = (Query *) lfirst(l);
+
+		query = fireRIRrules(query, NIL);
+
+		query->queryId = input_query_id;
+
+		results = lappend(results, query);
+	}
+
+	/*
+	 * Step 3
+	 *
+	 * Determine which, if any, of the resulting queries is supposed to set
+	 * the command-result tag; and update the canSetTag fields accordingly.
+	 *
+	 * If the original query is still in the list, it sets the command tag.
+	 * Otherwise, the last INSTEAD query of the same kind as the original is
+	 * allowed to set the tag.  (Note these rules can leave us with no query
+	 * setting the tag.  The tcop code has to cope with this by setting up a
+	 * default tag based on the original un-rewritten query.)
+	 *
+	 * The Asserts verify that at most one query in the result list is marked
+	 * canSetTag.  If we aren't checking asserts, we can fall out of the loop
+	 * as soon as we find the original query.
+	 */
+	origCmdType = parsetree->commandType;
+	foundOriginalQuery = false;
+	lastInstead = NULL;
+
+	foreach(l, results)
+	{
+		Query	   *query = (Query *) lfirst(l);
+
+		if (query->querySource == QSRC_ORIGINAL)
+		{
+			Assert(query->canSetTag);
+			Assert(!foundOriginalQuery);
+			foundOriginalQuery = true;
+#ifndef USE_ASSERT_CHECKING
+			break;
+#endif
+		}
+		else
+		{
+			Assert(!query->canSetTag);
+			if (query->commandType == origCmdType &&
+				(query->querySource == QSRC_INSTEAD_RULE ||
+				 query->querySource == QSRC_QUAL_INSTEAD_RULE))
+				lastInstead = query;
+		}
+	}
+
+	if (!foundOriginalQuery && lastInstead != NULL)
+		lastInstead->canSetTag = true;
+
+	return results;
+}