Adding upstream version 15.5.upstream/15.5

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

1 files changed, 2047 insertions, 0 deletions

diff --git a/src/backend/optimizer/util/relnode.c b/src/backend/optimizer/util/relnode.c
new file mode 100644
index 0000000..3c75fd5
--- /dev/null
+++ b/src/backend/optimizer/util/relnode.c
@@ -0,0 +1,2047 @@
+/*-------------------------------------------------------------------------
+ *
+ * relnode.c
+ *	  Relation-node lookup/construction routines
+ *
+ * Portions Copyright (c) 1996-2022, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/optimizer/util/relnode.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include <limits.h>
+
+#include "miscadmin.h"
+#include "nodes/nodeFuncs.h"
+#include "optimizer/appendinfo.h"
+#include "optimizer/clauses.h"
+#include "optimizer/cost.h"
+#include "optimizer/inherit.h"
+#include "optimizer/pathnode.h"
+#include "optimizer/paths.h"
+#include "optimizer/placeholder.h"
+#include "optimizer/plancat.h"
+#include "optimizer/restrictinfo.h"
+#include "optimizer/tlist.h"
+#include "utils/hsearch.h"
+#include "utils/lsyscache.h"
+
+
+typedef struct JoinHashEntry
+{
+	Relids		join_relids;	/* hash key --- MUST BE FIRST */
+	RelOptInfo *join_rel;
+} JoinHashEntry;
+
+static void build_joinrel_tlist(PlannerInfo *root, RelOptInfo *joinrel,
+								RelOptInfo *input_rel);
+static List *build_joinrel_restrictlist(PlannerInfo *root,
+										RelOptInfo *joinrel,
+										RelOptInfo *outer_rel,
+										RelOptInfo *inner_rel);
+static void build_joinrel_joinlist(RelOptInfo *joinrel,
+								   RelOptInfo *outer_rel,
+								   RelOptInfo *inner_rel);
+static List *subbuild_joinrel_restrictlist(RelOptInfo *joinrel,
+										   List *joininfo_list,
+										   List *new_restrictlist);
+static List *subbuild_joinrel_joinlist(RelOptInfo *joinrel,
+									   List *joininfo_list,
+									   List *new_joininfo);
+static void set_foreign_rel_properties(RelOptInfo *joinrel,
+									   RelOptInfo *outer_rel, RelOptInfo *inner_rel);
+static void add_join_rel(PlannerInfo *root, RelOptInfo *joinrel);
+static void build_joinrel_partition_info(RelOptInfo *joinrel,
+										 RelOptInfo *outer_rel, RelOptInfo *inner_rel,
+										 List *restrictlist, JoinType jointype);
+static bool have_partkey_equi_join(RelOptInfo *joinrel,
+								   RelOptInfo *rel1, RelOptInfo *rel2,
+								   JoinType jointype, List *restrictlist);
+static int	match_expr_to_partition_keys(Expr *expr, RelOptInfo *rel,
+										 bool strict_op);
+static void set_joinrel_partition_key_exprs(RelOptInfo *joinrel,
+											RelOptInfo *outer_rel, RelOptInfo *inner_rel,
+											JoinType jointype);
+static void build_child_join_reltarget(PlannerInfo *root,
+									   RelOptInfo *parentrel,
+									   RelOptInfo *childrel,
+									   int nappinfos,
+									   AppendRelInfo **appinfos);
+
+
+/*
+ * setup_simple_rel_arrays
+ *	  Prepare the arrays we use for quickly accessing base relations
+ *	  and AppendRelInfos.
+ */
+void
+setup_simple_rel_arrays(PlannerInfo *root)
+{
+	int			size;
+	Index		rti;
+	ListCell   *lc;
+
+	/* Arrays are accessed using RT indexes (1..N) */
+	size = list_length(root->parse->rtable) + 1;
+	root->simple_rel_array_size = size;
+
+	/*
+	 * simple_rel_array is initialized to all NULLs, since no RelOptInfos
+	 * exist yet.  It'll be filled by later calls to build_simple_rel().
+	 */
+	root->simple_rel_array = (RelOptInfo **)
+		palloc0(size * sizeof(RelOptInfo *));
+
+	/* simple_rte_array is an array equivalent of the rtable list */
+	root->simple_rte_array = (RangeTblEntry **)
+		palloc0(size * sizeof(RangeTblEntry *));
+	rti = 1;
+	foreach(lc, root->parse->rtable)
+	{
+		RangeTblEntry *rte = (RangeTblEntry *) lfirst(lc);
+
+		root->simple_rte_array[rti++] = rte;
+	}
+
+	/* append_rel_array is not needed if there are no AppendRelInfos */
+	if (root->append_rel_list == NIL)
+	{
+		root->append_rel_array = NULL;
+		return;
+	}
+
+	root->append_rel_array = (AppendRelInfo **)
+		palloc0(size * sizeof(AppendRelInfo *));
+
+	/*
+	 * append_rel_array is filled with any already-existing AppendRelInfos,
+	 * which currently could only come from UNION ALL flattening.  We might
+	 * add more later during inheritance expansion, but it's the
+	 * responsibility of the expansion code to update the array properly.
+	 */
+	foreach(lc, root->append_rel_list)
+	{
+		AppendRelInfo *appinfo = lfirst_node(AppendRelInfo, lc);
+		int			child_relid = appinfo->child_relid;
+
+		/* Sanity check */
+		Assert(child_relid < size);
+
+		if (root->append_rel_array[child_relid])
+			elog(ERROR, "child relation already exists");
+
+		root->append_rel_array[child_relid] = appinfo;
+	}
+}
+
+/*
+ * expand_planner_arrays
+ *		Expand the PlannerInfo's per-RTE arrays by add_size members
+ *		and initialize the newly added entries to NULLs
+ *
+ * Note: this causes the append_rel_array to become allocated even if
+ * it was not before.  This is okay for current uses, because we only call
+ * this when adding child relations, which always have AppendRelInfos.
+ */
+void
+expand_planner_arrays(PlannerInfo *root, int add_size)
+{
+	int			new_size;
+
+	Assert(add_size > 0);
+
+	new_size = root->simple_rel_array_size + add_size;
+
+	root->simple_rel_array = (RelOptInfo **)
+		repalloc(root->simple_rel_array,
+				 sizeof(RelOptInfo *) * new_size);
+	MemSet(root->simple_rel_array + root->simple_rel_array_size,
+		   0, sizeof(RelOptInfo *) * add_size);
+
+	root->simple_rte_array = (RangeTblEntry **)
+		repalloc(root->simple_rte_array,
+				 sizeof(RangeTblEntry *) * new_size);
+	MemSet(root->simple_rte_array + root->simple_rel_array_size,
+		   0, sizeof(RangeTblEntry *) * add_size);
+
+	if (root->append_rel_array)
+	{
+		root->append_rel_array = (AppendRelInfo **)
+			repalloc(root->append_rel_array,
+					 sizeof(AppendRelInfo *) * new_size);
+		MemSet(root->append_rel_array + root->simple_rel_array_size,
+			   0, sizeof(AppendRelInfo *) * add_size);
+	}
+	else
+	{
+		root->append_rel_array = (AppendRelInfo **)
+			palloc0(sizeof(AppendRelInfo *) * new_size);
+	}
+
+	root->simple_rel_array_size = new_size;
+}
+
+/*
+ * build_simple_rel
+ *	  Construct a new RelOptInfo for a base relation or 'other' relation.
+ */
+RelOptInfo *
+build_simple_rel(PlannerInfo *root, int relid, RelOptInfo *parent)
+{
+	RelOptInfo *rel;
+	RangeTblEntry *rte;
+
+	/* Rel should not exist already */
+	Assert(relid > 0 && relid < root->simple_rel_array_size);
+	if (root->simple_rel_array[relid] != NULL)
+		elog(ERROR, "rel %d already exists", relid);
+
+	/* Fetch RTE for relation */
+	rte = root->simple_rte_array[relid];
+	Assert(rte != NULL);
+
+	rel = makeNode(RelOptInfo);
+	rel->reloptkind = parent ? RELOPT_OTHER_MEMBER_REL : RELOPT_BASEREL;
+	rel->relids = bms_make_singleton(relid);
+	rel->rows = 0;
+	/* cheap startup cost is interesting iff not all tuples to be retrieved */
+	rel->consider_startup = (root->tuple_fraction > 0);
+	rel->consider_param_startup = false;	/* might get changed later */
+	rel->consider_parallel = false; /* might get changed later */
+	rel->reltarget = create_empty_pathtarget();
+	rel->pathlist = NIL;
+	rel->ppilist = NIL;
+	rel->partial_pathlist = NIL;
+	rel->cheapest_startup_path = NULL;
+	rel->cheapest_total_path = NULL;
+	rel->cheapest_unique_path = NULL;
+	rel->cheapest_parameterized_paths = NIL;
+	rel->relid = relid;
+	rel->rtekind = rte->rtekind;
+	/* min_attr, max_attr, attr_needed, attr_widths are set below */
+	rel->lateral_vars = NIL;
+	rel->indexlist = NIL;
+	rel->statlist = NIL;
+	rel->pages = 0;
+	rel->tuples = 0;
+	rel->allvisfrac = 0;
+	rel->eclass_indexes = NULL;
+	rel->subroot = NULL;
+	rel->subplan_params = NIL;
+	rel->rel_parallel_workers = -1; /* set up in get_relation_info */
+	rel->amflags = 0;
+	rel->serverid = InvalidOid;
+	rel->userid = rte->checkAsUser;
+	rel->useridiscurrent = false;
+	rel->fdwroutine = NULL;
+	rel->fdw_private = NULL;
+	rel->unique_for_rels = NIL;
+	rel->non_unique_for_rels = NIL;
+	rel->baserestrictinfo = NIL;
+	rel->baserestrictcost.startup = 0;
+	rel->baserestrictcost.per_tuple = 0;
+	rel->baserestrict_min_security = UINT_MAX;
+	rel->joininfo = NIL;
+	rel->has_eclass_joins = false;
+	rel->consider_partitionwise_join = false;	/* might get changed later */
+	rel->part_scheme = NULL;
+	rel->nparts = -1;
+	rel->boundinfo = NULL;
+	rel->partbounds_merged = false;
+	rel->partition_qual = NIL;
+	rel->part_rels = NULL;
+	rel->live_parts = NULL;
+	rel->all_partrels = NULL;
+	rel->partexprs = NULL;
+	rel->nullable_partexprs = NULL;
+
+	/*
+	 * Pass assorted information down the inheritance hierarchy.
+	 */
+	if (parent)
+	{
+		/*
+		 * Each direct or indirect child wants to know the relids of its
+		 * topmost parent.
+		 */
+		if (parent->top_parent_relids)
+			rel->top_parent_relids = parent->top_parent_relids;
+		else
+			rel->top_parent_relids = bms_copy(parent->relids);
+
+		/*
+		 * Also propagate lateral-reference information from appendrel parent
+		 * rels to their child rels.  We intentionally give each child rel the
+		 * same minimum parameterization, even though it's quite possible that
+		 * some don't reference all the lateral rels.  This is because any
+		 * append path for the parent will have to have the same
+		 * parameterization for every child anyway, and there's no value in
+		 * forcing extra reparameterize_path() calls.  Similarly, a lateral
+		 * reference to the parent prevents use of otherwise-movable join rels
+		 * for each child.
+		 *
+		 * It's possible for child rels to have their own children, in which
+		 * case the topmost parent's lateral info propagates all the way down.
+		 */
+		rel->direct_lateral_relids = parent->direct_lateral_relids;
+		rel->lateral_relids = parent->lateral_relids;
+		rel->lateral_referencers = parent->lateral_referencers;
+	}
+	else
+	{
+		rel->top_parent_relids = NULL;
+		rel->direct_lateral_relids = NULL;
+		rel->lateral_relids = NULL;
+		rel->lateral_referencers = NULL;
+	}
+
+	/* Check type of rtable entry */
+	switch (rte->rtekind)
+	{
+		case RTE_RELATION:
+			/* Table --- retrieve statistics from the system catalogs */
+			get_relation_info(root, rte->relid, rte->inh, rel);
+			break;
+		case RTE_SUBQUERY:
+		case RTE_FUNCTION:
+		case RTE_TABLEFUNC:
+		case RTE_VALUES:
+		case RTE_CTE:
+		case RTE_NAMEDTUPLESTORE:
+
+			/*
+			 * Subquery, function, tablefunc, values list, CTE, or ENR --- set
+			 * up attr range and arrays
+			 *
+			 * Note: 0 is included in range to support whole-row Vars
+			 */
+			rel->min_attr = 0;
+			rel->max_attr = list_length(rte->eref->colnames);
+			rel->attr_needed = (Relids *)
+				palloc0((rel->max_attr - rel->min_attr + 1) * sizeof(Relids));
+			rel->attr_widths = (int32 *)
+				palloc0((rel->max_attr - rel->min_attr + 1) * sizeof(int32));
+			break;
+		case RTE_RESULT:
+			/* RTE_RESULT has no columns, nor could it have whole-row Var */
+			rel->min_attr = 0;
+			rel->max_attr = -1;
+			rel->attr_needed = NULL;
+			rel->attr_widths = NULL;
+			break;
+		default:
+			elog(ERROR, "unrecognized RTE kind: %d",
+				 (int) rte->rtekind);
+			break;
+	}
+
+	/*
+	 * Copy the parent's quals to the child, with appropriate substitution of
+	 * variables.  If any constant false or NULL clauses turn up, we can mark
+	 * the child as dummy right away.  (We must do this immediately so that
+	 * pruning works correctly when recursing in expand_partitioned_rtentry.)
+	 */
+	if (parent)
+	{
+		AppendRelInfo *appinfo = root->append_rel_array[relid];
+
+		Assert(appinfo != NULL);
+		if (!apply_child_basequals(root, parent, rel, rte, appinfo))
+		{
+			/*
+			 * Some restriction clause reduced to constant FALSE or NULL after
+			 * substitution, so this child need not be scanned.
+			 */
+			mark_dummy_rel(rel);
+		}
+	}
+
+	/* Save the finished struct in the query's simple_rel_array */
+	root->simple_rel_array[relid] = rel;
+
+	return rel;
+}
+
+/*
+ * find_base_rel
+ *	  Find a base or other relation entry, which must already exist.
+ */
+RelOptInfo *
+find_base_rel(PlannerInfo *root, int relid)
+{
+	RelOptInfo *rel;
+
+	Assert(relid > 0);
+
+	if (relid < root->simple_rel_array_size)
+	{
+		rel = root->simple_rel_array[relid];
+		if (rel)
+			return rel;
+	}
+
+	elog(ERROR, "no relation entry for relid %d", relid);
+
+	return NULL;				/* keep compiler quiet */
+}
+
+/*
+ * build_join_rel_hash
+ *	  Construct the auxiliary hash table for join relations.
+ */
+static void
+build_join_rel_hash(PlannerInfo *root)
+{
+	HTAB	   *hashtab;
+	HASHCTL		hash_ctl;
+	ListCell   *l;
+
+	/* Create the hash table */
+	hash_ctl.keysize = sizeof(Relids);
+	hash_ctl.entrysize = sizeof(JoinHashEntry);
+	hash_ctl.hash = bitmap_hash;
+	hash_ctl.match = bitmap_match;
+	hash_ctl.hcxt = CurrentMemoryContext;
+	hashtab = hash_create("JoinRelHashTable",
+						  256L,
+						  &hash_ctl,
+						  HASH_ELEM | HASH_FUNCTION | HASH_COMPARE | HASH_CONTEXT);
+
+	/* Insert all the already-existing joinrels */
+	foreach(l, root->join_rel_list)
+	{
+		RelOptInfo *rel = (RelOptInfo *) lfirst(l);
+		JoinHashEntry *hentry;
+		bool		found;
+
+		hentry = (JoinHashEntry *) hash_search(hashtab,
+											   &(rel->relids),
+											   HASH_ENTER,
+											   &found);
+		Assert(!found);
+		hentry->join_rel = rel;
+	}
+
+	root->join_rel_hash = hashtab;
+}
+
+/*
+ * find_join_rel
+ *	  Returns relation entry corresponding to 'relids' (a set of RT indexes),
+ *	  or NULL if none exists.  This is for join relations.
+ */
+RelOptInfo *
+find_join_rel(PlannerInfo *root, Relids relids)
+{
+	/*
+	 * Switch to using hash lookup when list grows "too long".  The threshold
+	 * is arbitrary and is known only here.
+	 */
+	if (!root->join_rel_hash && list_length(root->join_rel_list) > 32)
+		build_join_rel_hash(root);
+
+	/*
+	 * Use either hashtable lookup or linear search, as appropriate.
+	 *
+	 * Note: the seemingly redundant hashkey variable is used to avoid taking
+	 * the address of relids; unless the compiler is exceedingly smart, doing
+	 * so would force relids out of a register and thus probably slow down the
+	 * list-search case.
+	 */
+	if (root->join_rel_hash)
+	{
+		Relids		hashkey = relids;
+		JoinHashEntry *hentry;
+
+		hentry = (JoinHashEntry *) hash_search(root->join_rel_hash,
+											   &hashkey,
+											   HASH_FIND,
+											   NULL);
+		if (hentry)
+			return hentry->join_rel;
+	}
+	else
+	{
+		ListCell   *l;
+
+		foreach(l, root->join_rel_list)
+		{
+			RelOptInfo *rel = (RelOptInfo *) lfirst(l);
+
+			if (bms_equal(rel->relids, relids))
+				return rel;
+		}
+	}
+
+	return NULL;
+}
+
+/*
+ * set_foreign_rel_properties
+ *		Set up foreign-join fields if outer and inner relation are foreign
+ *		tables (or joins) belonging to the same server and assigned to the same
+ *		user to check access permissions as.
+ *
+ * In addition to an exact match of userid, we allow the case where one side
+ * has zero userid (implying current user) and the other side has explicit
+ * userid that happens to equal the current user; but in that case, pushdown of
+ * the join is only valid for the current user.  The useridiscurrent field
+ * records whether we had to make such an assumption for this join or any
+ * sub-join.
+ *
+ * Otherwise these fields are left invalid, so GetForeignJoinPaths will not be
+ * called for the join relation.
+ *
+ */
+static void
+set_foreign_rel_properties(RelOptInfo *joinrel, RelOptInfo *outer_rel,
+						   RelOptInfo *inner_rel)
+{
+	if (OidIsValid(outer_rel->serverid) &&
+		inner_rel->serverid == outer_rel->serverid)
+	{
+		if (inner_rel->userid == outer_rel->userid)
+		{
+			joinrel->serverid = outer_rel->serverid;
+			joinrel->userid = outer_rel->userid;
+			joinrel->useridiscurrent = outer_rel->useridiscurrent || inner_rel->useridiscurrent;
+			joinrel->fdwroutine = outer_rel->fdwroutine;
+		}
+		else if (!OidIsValid(inner_rel->userid) &&
+				 outer_rel->userid == GetUserId())
+		{
+			joinrel->serverid = outer_rel->serverid;
+			joinrel->userid = outer_rel->userid;
+			joinrel->useridiscurrent = true;
+			joinrel->fdwroutine = outer_rel->fdwroutine;
+		}
+		else if (!OidIsValid(outer_rel->userid) &&
+				 inner_rel->userid == GetUserId())
+		{
+			joinrel->serverid = outer_rel->serverid;
+			joinrel->userid = inner_rel->userid;
+			joinrel->useridiscurrent = true;
+			joinrel->fdwroutine = outer_rel->fdwroutine;
+		}
+	}
+}
+
+/*
+ * add_join_rel
+ *		Add given join relation to the list of join relations in the given
+ *		PlannerInfo. Also add it to the auxiliary hashtable if there is one.
+ */
+static void
+add_join_rel(PlannerInfo *root, RelOptInfo *joinrel)
+{
+	/* GEQO requires us to append the new joinrel to the end of the list! */
+	root->join_rel_list = lappend(root->join_rel_list, joinrel);
+
+	/* store it into the auxiliary hashtable if there is one. */
+	if (root->join_rel_hash)
+	{
+		JoinHashEntry *hentry;
+		bool		found;
+
+		hentry = (JoinHashEntry *) hash_search(root->join_rel_hash,
+											   &(joinrel->relids),
+											   HASH_ENTER,
+											   &found);
+		Assert(!found);
+		hentry->join_rel = joinrel;
+	}
+}
+
+/*
+ * build_join_rel
+ *	  Returns relation entry corresponding to the union of two given rels,
+ *	  creating a new relation entry if none already exists.
+ *
+ * 'joinrelids' is the Relids set that uniquely identifies the join
+ * 'outer_rel' and 'inner_rel' are relation nodes for the relations to be
+ *		joined
+ * 'sjinfo': join context info
+ * 'restrictlist_ptr': result variable.  If not NULL, *restrictlist_ptr
+ *		receives the list of RestrictInfo nodes that apply to this
+ *		particular pair of joinable relations.
+ *
+ * restrictlist_ptr makes the routine's API a little grotty, but it saves
+ * duplicated calculation of the restrictlist...
+ */
+RelOptInfo *
+build_join_rel(PlannerInfo *root,
+			   Relids joinrelids,
+			   RelOptInfo *outer_rel,
+			   RelOptInfo *inner_rel,
+			   SpecialJoinInfo *sjinfo,
+			   List **restrictlist_ptr)
+{
+	RelOptInfo *joinrel;
+	List	   *restrictlist;
+
+	/* This function should be used only for join between parents. */
+	Assert(!IS_OTHER_REL(outer_rel) && !IS_OTHER_REL(inner_rel));
+
+	/*
+	 * See if we already have a joinrel for this set of base rels.
+	 */
+	joinrel = find_join_rel(root, joinrelids);
+
+	if (joinrel)
+	{
+		/*
+		 * Yes, so we only need to figure the restrictlist for this particular
+		 * pair of component relations.
+		 */
+		if (restrictlist_ptr)
+			*restrictlist_ptr = build_joinrel_restrictlist(root,
+														   joinrel,
+														   outer_rel,
+														   inner_rel);
+		return joinrel;
+	}
+
+	/*
+	 * Nope, so make one.
+	 */
+	joinrel = makeNode(RelOptInfo);
+	joinrel->reloptkind = RELOPT_JOINREL;
+	joinrel->relids = bms_copy(joinrelids);
+	joinrel->rows = 0;
+	/* cheap startup cost is interesting iff not all tuples to be retrieved */
+	joinrel->consider_startup = (root->tuple_fraction > 0);
+	joinrel->consider_param_startup = false;
+	joinrel->consider_parallel = false;
+	joinrel->reltarget = create_empty_pathtarget();
+	joinrel->pathlist = NIL;
+	joinrel->ppilist = NIL;
+	joinrel->partial_pathlist = NIL;
+	joinrel->cheapest_startup_path = NULL;
+	joinrel->cheapest_total_path = NULL;
+	joinrel->cheapest_unique_path = NULL;
+	joinrel->cheapest_parameterized_paths = NIL;
+	/* init direct_lateral_relids from children; we'll finish it up below */
+	joinrel->direct_lateral_relids =
+		bms_union(outer_rel->direct_lateral_relids,
+				  inner_rel->direct_lateral_relids);
+	joinrel->lateral_relids = min_join_parameterization(root, joinrel->relids,
+														outer_rel, inner_rel);
+	joinrel->relid = 0;			/* indicates not a baserel */
+	joinrel->rtekind = RTE_JOIN;
+	joinrel->min_attr = 0;
+	joinrel->max_attr = 0;
+	joinrel->attr_needed = NULL;
+	joinrel->attr_widths = NULL;
+	joinrel->lateral_vars = NIL;
+	joinrel->lateral_referencers = NULL;
+	joinrel->indexlist = NIL;
+	joinrel->statlist = NIL;
+	joinrel->pages = 0;
+	joinrel->tuples = 0;
+	joinrel->allvisfrac = 0;
+	joinrel->eclass_indexes = NULL;
+	joinrel->subroot = NULL;
+	joinrel->subplan_params = NIL;
+	joinrel->rel_parallel_workers = -1;
+	joinrel->amflags = 0;
+	joinrel->serverid = InvalidOid;
+	joinrel->userid = InvalidOid;
+	joinrel->useridiscurrent = false;
+	joinrel->fdwroutine = NULL;
+	joinrel->fdw_private = NULL;
+	joinrel->unique_for_rels = NIL;
+	joinrel->non_unique_for_rels = NIL;
+	joinrel->baserestrictinfo = NIL;
+	joinrel->baserestrictcost.startup = 0;
+	joinrel->baserestrictcost.per_tuple = 0;
+	joinrel->baserestrict_min_security = UINT_MAX;
+	joinrel->joininfo = NIL;
+	joinrel->has_eclass_joins = false;
+	joinrel->consider_partitionwise_join = false;	/* might get changed later */
+	joinrel->top_parent_relids = NULL;
+	joinrel->part_scheme = NULL;
+	joinrel->nparts = -1;
+	joinrel->boundinfo = NULL;
+	joinrel->partbounds_merged = false;
+	joinrel->partition_qual = NIL;
+	joinrel->part_rels = NULL;
+	joinrel->live_parts = NULL;
+	joinrel->all_partrels = NULL;
+	joinrel->partexprs = NULL;
+	joinrel->nullable_partexprs = NULL;
+
+	/* Compute information relevant to the foreign relations. */
+	set_foreign_rel_properties(joinrel, outer_rel, inner_rel);
+
+	/*
+	 * Create a new tlist containing just the vars that need to be output from
+	 * this join (ie, are needed for higher joinclauses or final output).
+	 *
+	 * NOTE: the tlist order for a join rel will depend on which pair of outer
+	 * and inner rels we first try to build it from.  But the contents should
+	 * be the same regardless.
+	 */
+	build_joinrel_tlist(root, joinrel, outer_rel);
+	build_joinrel_tlist(root, joinrel, inner_rel);
+	add_placeholders_to_joinrel(root, joinrel, outer_rel, inner_rel);
+
+	/*
+	 * add_placeholders_to_joinrel also took care of adding the ph_lateral
+	 * sets of any PlaceHolderVars computed here to direct_lateral_relids, so
+	 * now we can finish computing that.  This is much like the computation of
+	 * the transitively-closed lateral_relids in min_join_parameterization,
+	 * except that here we *do* have to consider the added PHVs.
+	 */
+	joinrel->direct_lateral_relids =
+		bms_del_members(joinrel->direct_lateral_relids, joinrel->relids);
+	if (bms_is_empty(joinrel->direct_lateral_relids))
+		joinrel->direct_lateral_relids = NULL;
+
+	/*
+	 * Construct restrict and join clause lists for the new joinrel. (The
+	 * caller might or might not need the restrictlist, but I need it anyway
+	 * for set_joinrel_size_estimates().)
+	 */
+	restrictlist = build_joinrel_restrictlist(root, joinrel,
+											  outer_rel, inner_rel);
+	if (restrictlist_ptr)
+		*restrictlist_ptr = restrictlist;
+	build_joinrel_joinlist(joinrel, outer_rel, inner_rel);
+
+	/*
+	 * This is also the right place to check whether the joinrel has any
+	 * pending EquivalenceClass joins.
+	 */
+	joinrel->has_eclass_joins = has_relevant_eclass_joinclause(root, joinrel);
+
+	/* Store the partition information. */
+	build_joinrel_partition_info(joinrel, outer_rel, inner_rel, restrictlist,
+								 sjinfo->jointype);
+
+	/*
+	 * Set estimates of the joinrel's size.
+	 */
+	set_joinrel_size_estimates(root, joinrel, outer_rel, inner_rel,
+							   sjinfo, restrictlist);
+
+	/*
+	 * Set the consider_parallel flag if this joinrel could potentially be
+	 * scanned within a parallel worker.  If this flag is false for either
+	 * inner_rel or outer_rel, then it must be false for the joinrel also.
+	 * Even if both are true, there might be parallel-restricted expressions
+	 * in the targetlist or quals.
+	 *
+	 * Note that if there are more than two rels in this relation, they could
+	 * be divided between inner_rel and outer_rel in any arbitrary way.  We
+	 * assume this doesn't matter, because we should hit all the same baserels
+	 * and joinclauses while building up to this joinrel no matter which we
+	 * take; therefore, we should make the same decision here however we get
+	 * here.
+	 */
+	if (inner_rel->consider_parallel && outer_rel->consider_parallel &&
+		is_parallel_safe(root, (Node *) restrictlist) &&
+		is_parallel_safe(root, (Node *) joinrel->reltarget->exprs))
+		joinrel->consider_parallel = true;
+
+	/* Add the joinrel to the PlannerInfo. */
+	add_join_rel(root, joinrel);
+
+	/*
+	 * Also, if dynamic-programming join search is active, add the new joinrel
+	 * to the appropriate sublist.  Note: you might think the Assert on number
+	 * of members should be for equality, but some of the level 1 rels might
+	 * have been joinrels already, so we can only assert <=.
+	 */
+	if (root->join_rel_level)
+	{
+		Assert(root->join_cur_level > 0);
+		Assert(root->join_cur_level <= bms_num_members(joinrel->relids));
+		root->join_rel_level[root->join_cur_level] =
+			lappend(root->join_rel_level[root->join_cur_level], joinrel);
+	}
+
+	return joinrel;
+}
+
+/*
+ * build_child_join_rel
+ *	  Builds RelOptInfo representing join between given two child relations.
+ *
+ * 'outer_rel' and 'inner_rel' are the RelOptInfos of child relations being
+ *		joined
+ * 'parent_joinrel' is the RelOptInfo representing the join between parent
+ *		relations. Some of the members of new RelOptInfo are produced by
+ *		translating corresponding members of this RelOptInfo
+ * 'sjinfo': child-join context info
+ * 'restrictlist': list of RestrictInfo nodes that apply to this particular
+ *		pair of joinable relations
+ * 'jointype' is the join type (inner, left, full, etc)
+ */
+RelOptInfo *
+build_child_join_rel(PlannerInfo *root, RelOptInfo *outer_rel,
+					 RelOptInfo *inner_rel, RelOptInfo *parent_joinrel,
+					 List *restrictlist, SpecialJoinInfo *sjinfo,
+					 JoinType jointype)
+{
+	RelOptInfo *joinrel = makeNode(RelOptInfo);
+	AppendRelInfo **appinfos;
+	int			nappinfos;
+
+	/* Only joins between "other" relations land here. */
+	Assert(IS_OTHER_REL(outer_rel) && IS_OTHER_REL(inner_rel));
+
+	/* The parent joinrel should have consider_partitionwise_join set. */
+	Assert(parent_joinrel->consider_partitionwise_join);
+
+	joinrel->reloptkind = RELOPT_OTHER_JOINREL;
+	joinrel->relids = bms_union(outer_rel->relids, inner_rel->relids);
+	joinrel->rows = 0;
+	/* cheap startup cost is interesting iff not all tuples to be retrieved */
+	joinrel->consider_startup = (root->tuple_fraction > 0);
+	joinrel->consider_param_startup = false;
+	joinrel->consider_parallel = false;
+	joinrel->reltarget = create_empty_pathtarget();
+	joinrel->pathlist = NIL;
+	joinrel->ppilist = NIL;
+	joinrel->partial_pathlist = NIL;
+	joinrel->cheapest_startup_path = NULL;
+	joinrel->cheapest_total_path = NULL;
+	joinrel->cheapest_unique_path = NULL;
+	joinrel->cheapest_parameterized_paths = NIL;
+	joinrel->direct_lateral_relids = NULL;
+	joinrel->lateral_relids = NULL;
+	joinrel->relid = 0;			/* indicates not a baserel */
+	joinrel->rtekind = RTE_JOIN;
+	joinrel->min_attr = 0;
+	joinrel->max_attr = 0;
+	joinrel->attr_needed = NULL;
+	joinrel->attr_widths = NULL;
+	joinrel->lateral_vars = NIL;
+	joinrel->lateral_referencers = NULL;
+	joinrel->indexlist = NIL;
+	joinrel->pages = 0;
+	joinrel->tuples = 0;
+	joinrel->allvisfrac = 0;
+	joinrel->eclass_indexes = NULL;
+	joinrel->subroot = NULL;
+	joinrel->subplan_params = NIL;
+	joinrel->amflags = 0;
+	joinrel->serverid = InvalidOid;
+	joinrel->userid = InvalidOid;
+	joinrel->useridiscurrent = false;
+	joinrel->fdwroutine = NULL;
+	joinrel->fdw_private = NULL;
+	joinrel->baserestrictinfo = NIL;
+	joinrel->baserestrictcost.startup = 0;
+	joinrel->baserestrictcost.per_tuple = 0;
+	joinrel->joininfo = NIL;
+	joinrel->has_eclass_joins = false;
+	joinrel->consider_partitionwise_join = false;	/* might get changed later */
+	joinrel->top_parent_relids = NULL;
+	joinrel->part_scheme = NULL;
+	joinrel->nparts = -1;
+	joinrel->boundinfo = NULL;
+	joinrel->partbounds_merged = false;
+	joinrel->partition_qual = NIL;
+	joinrel->part_rels = NULL;
+	joinrel->live_parts = NULL;
+	joinrel->all_partrels = NULL;
+	joinrel->partexprs = NULL;
+	joinrel->nullable_partexprs = NULL;
+
+	joinrel->top_parent_relids = bms_union(outer_rel->top_parent_relids,
+										   inner_rel->top_parent_relids);
+
+	/* Compute information relevant to foreign relations. */
+	set_foreign_rel_properties(joinrel, outer_rel, inner_rel);
+
+	/* Compute information needed for mapping Vars to the child rel */
+	appinfos = find_appinfos_by_relids(root, joinrel->relids, &nappinfos);
+
+	/* Set up reltarget struct */
+	build_child_join_reltarget(root, parent_joinrel, joinrel,
+							   nappinfos, appinfos);
+
+	/* Construct joininfo list. */
+	joinrel->joininfo = (List *) adjust_appendrel_attrs(root,
+														(Node *) parent_joinrel->joininfo,
+														nappinfos,
+														appinfos);
+
+	/*
+	 * Lateral relids referred in child join will be same as that referred in
+	 * the parent relation.
+	 */
+	joinrel->direct_lateral_relids = (Relids) bms_copy(parent_joinrel->direct_lateral_relids);
+	joinrel->lateral_relids = (Relids) bms_copy(parent_joinrel->lateral_relids);
+
+	/*
+	 * If the parent joinrel has pending equivalence classes, so does the
+	 * child.
+	 */
+	joinrel->has_eclass_joins = parent_joinrel->has_eclass_joins;
+
+	/* Is the join between partitions itself partitioned? */
+	build_joinrel_partition_info(joinrel, outer_rel, inner_rel, restrictlist,
+								 jointype);
+
+	/* Child joinrel is parallel safe if parent is parallel safe. */
+	joinrel->consider_parallel = parent_joinrel->consider_parallel;
+
+	/* Set estimates of the child-joinrel's size. */
+	set_joinrel_size_estimates(root, joinrel, outer_rel, inner_rel,
+							   sjinfo, restrictlist);
+
+	/* We build the join only once. */
+	Assert(!find_join_rel(root, joinrel->relids));
+
+	/* Add the relation to the PlannerInfo. */
+	add_join_rel(root, joinrel);
+
+	/*
+	 * We might need EquivalenceClass members corresponding to the child join,
+	 * so that we can represent sort pathkeys for it.  As with children of
+	 * baserels, we shouldn't need this unless there are relevant eclass joins
+	 * (implying that a merge join might be possible) or pathkeys to sort by.
+	 */
+	if (joinrel->has_eclass_joins || has_useful_pathkeys(root, parent_joinrel))
+		add_child_join_rel_equivalences(root,
+										nappinfos, appinfos,
+										parent_joinrel, joinrel);
+
+	pfree(appinfos);
+
+	return joinrel;
+}
+
+/*
+ * min_join_parameterization
+ *
+ * Determine the minimum possible parameterization of a joinrel, that is, the
+ * set of other rels it contains LATERAL references to.  We save this value in
+ * the join's RelOptInfo.  This function is split out of build_join_rel()
+ * because join_is_legal() needs the value to check a prospective join.
+ */
+Relids
+min_join_parameterization(PlannerInfo *root,
+						  Relids joinrelids,
+						  RelOptInfo *outer_rel,
+						  RelOptInfo *inner_rel)
+{
+	Relids		result;
+
+	/*
+	 * Basically we just need the union of the inputs' lateral_relids, less
+	 * whatever is already in the join.
+	 *
+	 * It's not immediately obvious that this is a valid way to compute the
+	 * result, because it might seem that we're ignoring possible lateral refs
+	 * of PlaceHolderVars that are due to be computed at the join but not in
+	 * either input.  However, because create_lateral_join_info() already
+	 * charged all such PHV refs to each member baserel of the join, they'll
+	 * be accounted for already in the inputs' lateral_relids.  Likewise, we
+	 * do not need to worry about doing transitive closure here, because that
+	 * was already accounted for in the original baserel lateral_relids.
+	 */
+	result = bms_union(outer_rel->lateral_relids, inner_rel->lateral_relids);
+	result = bms_del_members(result, joinrelids);
+
+	/* Maintain invariant that result is exactly NULL if empty */
+	if (bms_is_empty(result))
+		result = NULL;
+
+	return result;
+}
+
+/*
+ * build_joinrel_tlist
+ *	  Builds a join relation's target list from an input relation.
+ *	  (This is invoked twice to handle the two input relations.)
+ *
+ * The join's targetlist includes all Vars of its member relations that
+ * will still be needed above the join.  This subroutine adds all such
+ * Vars from the specified input rel's tlist to the join rel's tlist.
+ *
+ * We also compute the expected width of the join's output, making use
+ * of data that was cached at the baserel level by set_rel_width().
+ */
+static void
+build_joinrel_tlist(PlannerInfo *root, RelOptInfo *joinrel,
+					RelOptInfo *input_rel)
+{
+	Relids		relids = joinrel->relids;
+	ListCell   *vars;
+
+	foreach(vars, input_rel->reltarget->exprs)
+	{
+		Var		   *var = (Var *) lfirst(vars);
+
+		/*
+		 * Ignore PlaceHolderVars in the input tlists; we'll make our own
+		 * decisions about whether to copy them.
+		 */
+		if (IsA(var, PlaceHolderVar))
+			continue;
+
+		/*
+		 * Otherwise, anything in a baserel or joinrel targetlist ought to be
+		 * a Var.  (More general cases can only appear in appendrel child
+		 * rels, which will never be seen here.)
+		 */
+		if (!IsA(var, Var))
+			elog(ERROR, "unexpected node type in rel targetlist: %d",
+				 (int) nodeTag(var));
+
+		if (var->varno == ROWID_VAR)
+		{
+			/* UPDATE/DELETE/MERGE row identity vars are always needed */
+			RowIdentityVarInfo *ridinfo = (RowIdentityVarInfo *)
+			list_nth(root->row_identity_vars, var->varattno - 1);
+
+			joinrel->reltarget->exprs = lappend(joinrel->reltarget->exprs,
+												var);
+			/* Vars have cost zero, so no need to adjust reltarget->cost */
+			joinrel->reltarget->width += ridinfo->rowidwidth;
+		}
+		else
+		{
+			RelOptInfo *baserel;
+			int			ndx;
+
+			/* Get the Var's original base rel */
+			baserel = find_base_rel(root, var->varno);
+
+			/* Is it still needed above this joinrel? */
+			ndx = var->varattno - baserel->min_attr;
+			if (bms_nonempty_difference(baserel->attr_needed[ndx], relids))
+			{
+				/* Yup, add it to the output */
+				joinrel->reltarget->exprs = lappend(joinrel->reltarget->exprs,
+													var);
+				/* Vars have cost zero, so no need to adjust reltarget->cost */
+				joinrel->reltarget->width += baserel->attr_widths[ndx];
+			}
+		}
+	}
+}
+
+/*
+ * build_joinrel_restrictlist
+ * build_joinrel_joinlist
+ *	  These routines build lists of restriction and join clauses for a
+ *	  join relation from the joininfo lists of the relations it joins.
+ *
+ *	  These routines are separate because the restriction list must be
+ *	  built afresh for each pair of input sub-relations we consider, whereas
+ *	  the join list need only be computed once for any join RelOptInfo.
+ *	  The join list is fully determined by the set of rels making up the
+ *	  joinrel, so we should get the same results (up to ordering) from any
+ *	  candidate pair of sub-relations.  But the restriction list is whatever
+ *	  is not handled in the sub-relations, so it depends on which
+ *	  sub-relations are considered.
+ *
+ *	  If a join clause from an input relation refers to base rels still not
+ *	  present in the joinrel, then it is still a join clause for the joinrel;
+ *	  we put it into the joininfo list for the joinrel.  Otherwise,
+ *	  the clause is now a restrict clause for the joined relation, and we
+ *	  return it to the caller of build_joinrel_restrictlist() to be stored in
+ *	  join paths made from this pair of sub-relations.  (It will not need to
+ *	  be considered further up the join tree.)
+ *
+ *	  In many cases we will find the same RestrictInfos in both input
+ *	  relations' joinlists, so be careful to eliminate duplicates.
+ *	  Pointer equality should be a sufficient test for dups, since all
+ *	  the various joinlist entries ultimately refer to RestrictInfos
+ *	  pushed into them by distribute_restrictinfo_to_rels().
+ *
+ * 'joinrel' is a join relation node
+ * 'outer_rel' and 'inner_rel' are a pair of relations that can be joined
+ *		to form joinrel.
+ *
+ * build_joinrel_restrictlist() returns a list of relevant restrictinfos,
+ * whereas build_joinrel_joinlist() stores its results in the joinrel's
+ * joininfo list.  One or the other must accept each given clause!
+ *
+ * NB: Formerly, we made deep(!) copies of each input RestrictInfo to pass
+ * up to the join relation.  I believe this is no longer necessary, because
+ * RestrictInfo nodes are no longer context-dependent.  Instead, just include
+ * the original nodes in the lists made for the join relation.
+ */
+static List *
+build_joinrel_restrictlist(PlannerInfo *root,
+						   RelOptInfo *joinrel,
+						   RelOptInfo *outer_rel,
+						   RelOptInfo *inner_rel)
+{
+	List	   *result;
+
+	/*
+	 * Collect all the clauses that syntactically belong at this level,
+	 * eliminating any duplicates (important since we will see many of the
+	 * same clauses arriving from both input relations).
+	 */
+	result = subbuild_joinrel_restrictlist(joinrel, outer_rel->joininfo, NIL);
+	result = subbuild_joinrel_restrictlist(joinrel, inner_rel->joininfo, result);
+
+	/*
+	 * Add on any clauses derived from EquivalenceClasses.  These cannot be
+	 * redundant with the clauses in the joininfo lists, so don't bother
+	 * checking.
+	 */
+	result = list_concat(result,
+						 generate_join_implied_equalities(root,
+														  joinrel->relids,
+														  outer_rel->relids,
+														  inner_rel));
+
+	return result;
+}
+
+static void
+build_joinrel_joinlist(RelOptInfo *joinrel,
+					   RelOptInfo *outer_rel,
+					   RelOptInfo *inner_rel)
+{
+	List	   *result;
+
+	/*
+	 * Collect all the clauses that syntactically belong above this level,
+	 * eliminating any duplicates (important since we will see many of the
+	 * same clauses arriving from both input relations).
+	 */
+	result = subbuild_joinrel_joinlist(joinrel, outer_rel->joininfo, NIL);
+	result = subbuild_joinrel_joinlist(joinrel, inner_rel->joininfo, result);
+
+	joinrel->joininfo = result;
+}
+
+static List *
+subbuild_joinrel_restrictlist(RelOptInfo *joinrel,
+							  List *joininfo_list,
+							  List *new_restrictlist)
+{
+	ListCell   *l;
+
+	foreach(l, joininfo_list)
+	{
+		RestrictInfo *rinfo = (RestrictInfo *) lfirst(l);
+
+		if (bms_is_subset(rinfo->required_relids, joinrel->relids))
+		{
+			/*
+			 * This clause becomes a restriction clause for the joinrel, since
+			 * it refers to no outside rels.  Add it to the list, being
+			 * careful to eliminate duplicates. (Since RestrictInfo nodes in
+			 * different joinlists will have been multiply-linked rather than
+			 * copied, pointer equality should be a sufficient test.)
+			 */
+			new_restrictlist = list_append_unique_ptr(new_restrictlist, rinfo);
+		}
+		else
+		{
+			/*
+			 * This clause is still a join clause at this level, so we ignore
+			 * it in this routine.
+			 */
+		}
+	}
+
+	return new_restrictlist;
+}
+
+static List *
+subbuild_joinrel_joinlist(RelOptInfo *joinrel,
+						  List *joininfo_list,
+						  List *new_joininfo)
+{
+	ListCell   *l;
+
+	/* Expected to be called only for join between parent relations. */
+	Assert(joinrel->reloptkind == RELOPT_JOINREL);
+
+	foreach(l, joininfo_list)
+	{
+		RestrictInfo *rinfo = (RestrictInfo *) lfirst(l);
+
+		if (bms_is_subset(rinfo->required_relids, joinrel->relids))
+		{
+			/*
+			 * This clause becomes a restriction clause for the joinrel, since
+			 * it refers to no outside rels.  So we can ignore it in this
+			 * routine.
+			 */
+		}
+		else
+		{
+			/*
+			 * This clause is still a join clause at this level, so add it to
+			 * the new joininfo list, being careful to eliminate duplicates.
+			 * (Since RestrictInfo nodes in different joinlists will have been
+			 * multiply-linked rather than copied, pointer equality should be
+			 * a sufficient test.)
+			 */
+			new_joininfo = list_append_unique_ptr(new_joininfo, rinfo);
+		}
+	}
+
+	return new_joininfo;
+}
+
+
+/*
+ * fetch_upper_rel
+ *		Build a RelOptInfo describing some post-scan/join query processing,
+ *		or return a pre-existing one if somebody already built it.
+ *
+ * An "upper" relation is identified by an UpperRelationKind and a Relids set.
+ * The meaning of the Relids set is not specified here, and very likely will
+ * vary for different relation kinds.
+ *
+ * Most of the fields in an upper-level RelOptInfo are not used and are not
+ * set here (though makeNode should ensure they're zeroes).  We basically only
+ * care about fields that are of interest to add_path() and set_cheapest().
+ */
+RelOptInfo *
+fetch_upper_rel(PlannerInfo *root, UpperRelationKind kind, Relids relids)
+{
+	RelOptInfo *upperrel;
+	ListCell   *lc;
+
+	/*
+	 * For the moment, our indexing data structure is just a List for each
+	 * relation kind.  If we ever get so many of one kind that this stops
+	 * working well, we can improve it.  No code outside this function should
+	 * assume anything about how to find a particular upperrel.
+	 */
+
+	/* If we already made this upperrel for the query, return it */
+	foreach(lc, root->upper_rels[kind])
+	{
+		upperrel = (RelOptInfo *) lfirst(lc);
+
+		if (bms_equal(upperrel->relids, relids))
+			return upperrel;
+	}
+
+	upperrel = makeNode(RelOptInfo);
+	upperrel->reloptkind = RELOPT_UPPER_REL;
+	upperrel->relids = bms_copy(relids);
+
+	/* cheap startup cost is interesting iff not all tuples to be retrieved */
+	upperrel->consider_startup = (root->tuple_fraction > 0);
+	upperrel->consider_param_startup = false;
+	upperrel->consider_parallel = false;	/* might get changed later */
+	upperrel->reltarget = create_empty_pathtarget();
+	upperrel->pathlist = NIL;
+	upperrel->cheapest_startup_path = NULL;
+	upperrel->cheapest_total_path = NULL;
+	upperrel->cheapest_unique_path = NULL;
+	upperrel->cheapest_parameterized_paths = NIL;
+
+	root->upper_rels[kind] = lappend(root->upper_rels[kind], upperrel);
+
+	return upperrel;
+}
+
+
+/*
+ * find_childrel_parents
+ *		Compute the set of parent relids of an appendrel child rel.
+ *
+ * Since appendrels can be nested, a child could have multiple levels of
+ * appendrel ancestors.  This function computes a Relids set of all the
+ * parent relation IDs.
+ */
+Relids
+find_childrel_parents(PlannerInfo *root, RelOptInfo *rel)
+{
+	Relids		result = NULL;
+
+	Assert(rel->reloptkind == RELOPT_OTHER_MEMBER_REL);
+	Assert(rel->relid > 0 && rel->relid < root->simple_rel_array_size);
+
+	do
+	{
+		AppendRelInfo *appinfo = root->append_rel_array[rel->relid];
+		Index		prelid = appinfo->parent_relid;
+
+		result = bms_add_member(result, prelid);
+
+		/* traverse up to the parent rel, loop if it's also a child rel */
+		rel = find_base_rel(root, prelid);
+	} while (rel->reloptkind == RELOPT_OTHER_MEMBER_REL);
+
+	Assert(rel->reloptkind == RELOPT_BASEREL);
+
+	return result;
+}
+
+
+/*
+ * get_baserel_parampathinfo
+ *		Get the ParamPathInfo for a parameterized path for a base relation,
+ *		constructing one if we don't have one already.
+ *
+ * This centralizes estimating the rowcounts for parameterized paths.
+ * We need to cache those to be sure we use the same rowcount for all paths
+ * of the same parameterization for a given rel.  This is also a convenient
+ * place to determine which movable join clauses the parameterized path will
+ * be responsible for evaluating.
+ */
+ParamPathInfo *
+get_baserel_parampathinfo(PlannerInfo *root, RelOptInfo *baserel,
+						  Relids required_outer)
+{
+	ParamPathInfo *ppi;
+	Relids		joinrelids;
+	List	   *pclauses;
+	double		rows;
+	ListCell   *lc;
+
+	/* If rel has LATERAL refs, every path for it should account for them */
+	Assert(bms_is_subset(baserel->lateral_relids, required_outer));
+
+	/* Unparameterized paths have no ParamPathInfo */
+	if (bms_is_empty(required_outer))
+		return NULL;
+
+	Assert(!bms_overlap(baserel->relids, required_outer));
+
+	/* If we already have a PPI for this parameterization, just return it */
+	if ((ppi = find_param_path_info(baserel, required_outer)))
+		return ppi;
+
+	/*
+	 * Identify all joinclauses that are movable to this base rel given this
+	 * parameterization.
+	 */
+	joinrelids = bms_union(baserel->relids, required_outer);
+	pclauses = NIL;
+	foreach(lc, baserel->joininfo)
+	{
+		RestrictInfo *rinfo = (RestrictInfo *) lfirst(lc);
+
+		if (join_clause_is_movable_into(rinfo,
+										baserel->relids,
+										joinrelids))
+			pclauses = lappend(pclauses, rinfo);
+	}
+
+	/*
+	 * Add in joinclauses generated by EquivalenceClasses, too.  (These
+	 * necessarily satisfy join_clause_is_movable_into.)
+	 */
+	pclauses = list_concat(pclauses,
+						   generate_join_implied_equalities(root,
+															joinrelids,
+															required_outer,
+															baserel));
+
+	/* Estimate the number of rows returned by the parameterized scan */
+	rows = get_parameterized_baserel_size(root, baserel, pclauses);
+
+	/* And now we can build the ParamPathInfo */
+	ppi = makeNode(ParamPathInfo);
+	ppi->ppi_req_outer = required_outer;
+	ppi->ppi_rows = rows;
+	ppi->ppi_clauses = pclauses;
+	baserel->ppilist = lappend(baserel->ppilist, ppi);
+
+	return ppi;
+}
+
+/*
+ * get_joinrel_parampathinfo
+ *		Get the ParamPathInfo for a parameterized path for a join relation,
+ *		constructing one if we don't have one already.
+ *
+ * This centralizes estimating the rowcounts for parameterized paths.
+ * We need to cache those to be sure we use the same rowcount for all paths
+ * of the same parameterization for a given rel.  This is also a convenient
+ * place to determine which movable join clauses the parameterized path will
+ * be responsible for evaluating.
+ *
+ * outer_path and inner_path are a pair of input paths that can be used to
+ * construct the join, and restrict_clauses is the list of regular join
+ * clauses (including clauses derived from EquivalenceClasses) that must be
+ * applied at the join node when using these inputs.
+ *
+ * Unlike the situation for base rels, the set of movable join clauses to be
+ * enforced at a join varies with the selected pair of input paths, so we
+ * must calculate that and pass it back, even if we already have a matching
+ * ParamPathInfo.  We handle this by adding any clauses moved down to this
+ * join to *restrict_clauses, which is an in/out parameter.  (The addition
+ * is done in such a way as to not modify the passed-in List structure.)
+ *
+ * Note: when considering a nestloop join, the caller must have removed from
+ * restrict_clauses any movable clauses that are themselves scheduled to be
+ * pushed into the right-hand path.  We do not do that here since it's
+ * unnecessary for other join types.
+ */
+ParamPathInfo *
+get_joinrel_parampathinfo(PlannerInfo *root, RelOptInfo *joinrel,
+						  Path *outer_path,
+						  Path *inner_path,
+						  SpecialJoinInfo *sjinfo,
+						  Relids required_outer,
+						  List **restrict_clauses)
+{
+	ParamPathInfo *ppi;
+	Relids		join_and_req;
+	Relids		outer_and_req;
+	Relids		inner_and_req;
+	List	   *pclauses;
+	List	   *eclauses;
+	List	   *dropped_ecs;
+	double		rows;
+	ListCell   *lc;
+
+	/* If rel has LATERAL refs, every path for it should account for them */
+	Assert(bms_is_subset(joinrel->lateral_relids, required_outer));
+
+	/* Unparameterized paths have no ParamPathInfo or extra join clauses */
+	if (bms_is_empty(required_outer))
+		return NULL;
+
+	Assert(!bms_overlap(joinrel->relids, required_outer));
+
+	/*
+	 * Identify all joinclauses that are movable to this join rel given this
+	 * parameterization.  These are the clauses that are movable into this
+	 * join, but not movable into either input path.  Treat an unparameterized
+	 * input path as not accepting parameterized clauses (because it won't,
+	 * per the shortcut exit above), even though the joinclause movement rules
+	 * might allow the same clauses to be moved into a parameterized path for
+	 * that rel.
+	 */
+	join_and_req = bms_union(joinrel->relids, required_outer);
+	if (outer_path->param_info)
+		outer_and_req = bms_union(outer_path->parent->relids,
+								  PATH_REQ_OUTER(outer_path));
+	else
+		outer_and_req = NULL;	/* outer path does not accept parameters */
+	if (inner_path->param_info)
+		inner_and_req = bms_union(inner_path->parent->relids,
+								  PATH_REQ_OUTER(inner_path));
+	else
+		inner_and_req = NULL;	/* inner path does not accept parameters */
+
+	pclauses = NIL;
+	foreach(lc, joinrel->joininfo)
+	{
+		RestrictInfo *rinfo = (RestrictInfo *) lfirst(lc);
+
+		if (join_clause_is_movable_into(rinfo,
+										joinrel->relids,
+										join_and_req) &&
+			!join_clause_is_movable_into(rinfo,
+										 outer_path->parent->relids,
+										 outer_and_req) &&
+			!join_clause_is_movable_into(rinfo,
+										 inner_path->parent->relids,
+										 inner_and_req))
+			pclauses = lappend(pclauses, rinfo);
+	}
+
+	/* Consider joinclauses generated by EquivalenceClasses, too */
+	eclauses = generate_join_implied_equalities(root,
+												join_and_req,
+												required_outer,
+												joinrel);
+	/* We only want ones that aren't movable to lower levels */
+	dropped_ecs = NIL;
+	foreach(lc, eclauses)
+	{
+		RestrictInfo *rinfo = (RestrictInfo *) lfirst(lc);
+
+		/*
+		 * In principle, join_clause_is_movable_into() should accept anything
+		 * returned by generate_join_implied_equalities(); but because its
+		 * analysis is only approximate, sometimes it doesn't.  So we
+		 * currently cannot use this Assert; instead just assume it's okay to
+		 * apply the joinclause at this level.
+		 */
+#ifdef NOT_USED
+		Assert(join_clause_is_movable_into(rinfo,
+										   joinrel->relids,
+										   join_and_req));
+#endif
+		if (join_clause_is_movable_into(rinfo,
+										outer_path->parent->relids,
+										outer_and_req))
+			continue;			/* drop if movable into LHS */
+		if (join_clause_is_movable_into(rinfo,
+										inner_path->parent->relids,
+										inner_and_req))
+		{
+			/* drop if movable into RHS, but remember EC for use below */
+			Assert(rinfo->left_ec == rinfo->right_ec);
+			dropped_ecs = lappend(dropped_ecs, rinfo->left_ec);
+			continue;
+		}
+		pclauses = lappend(pclauses, rinfo);
+	}
+
+	/*
+	 * EquivalenceClasses are harder to deal with than we could wish, because
+	 * of the fact that a given EC can generate different clauses depending on
+	 * context.  Suppose we have an EC {X.X, Y.Y, Z.Z} where X and Y are the
+	 * LHS and RHS of the current join and Z is in required_outer, and further
+	 * suppose that the inner_path is parameterized by both X and Z.  The code
+	 * above will have produced either Z.Z = X.X or Z.Z = Y.Y from that EC,
+	 * and in the latter case will have discarded it as being movable into the
+	 * RHS.  However, the EC machinery might have produced either Y.Y = X.X or
+	 * Y.Y = Z.Z as the EC enforcement clause within the inner_path; it will
+	 * not have produced both, and we can't readily tell from here which one
+	 * it did pick.  If we add no clause to this join, we'll end up with
+	 * insufficient enforcement of the EC; either Z.Z or X.X will fail to be
+	 * constrained to be equal to the other members of the EC.  (When we come
+	 * to join Z to this X/Y path, we will certainly drop whichever EC clause
+	 * is generated at that join, so this omission won't get fixed later.)
+	 *
+	 * To handle this, for each EC we discarded such a clause from, try to
+	 * generate a clause connecting the required_outer rels to the join's LHS
+	 * ("Z.Z = X.X" in the terms of the above example).  If successful, and if
+	 * the clause can't be moved to the LHS, add it to the current join's
+	 * restriction clauses.  (If an EC cannot generate such a clause then it
+	 * has nothing that needs to be enforced here, while if the clause can be
+	 * moved into the LHS then it should have been enforced within that path.)
+	 *
+	 * Note that we don't need similar processing for ECs whose clause was
+	 * considered to be movable into the LHS, because the LHS can't refer to
+	 * the RHS so there is no comparable ambiguity about what it might
+	 * actually be enforcing internally.
+	 */
+	if (dropped_ecs)
+	{
+		Relids		real_outer_and_req;
+
+		real_outer_and_req = bms_union(outer_path->parent->relids,
+									   required_outer);
+		eclauses =
+			generate_join_implied_equalities_for_ecs(root,
+													 dropped_ecs,
+													 real_outer_and_req,
+													 required_outer,
+													 outer_path->parent);
+		foreach(lc, eclauses)
+		{
+			RestrictInfo *rinfo = (RestrictInfo *) lfirst(lc);
+
+			/* As above, can't quite assert this here */
+#ifdef NOT_USED
+			Assert(join_clause_is_movable_into(rinfo,
+											   outer_path->parent->relids,
+											   real_outer_and_req));
+#endif
+			if (!join_clause_is_movable_into(rinfo,
+											 outer_path->parent->relids,
+											 outer_and_req))
+				pclauses = lappend(pclauses, rinfo);
+		}
+	}
+
+	/*
+	 * Now, attach the identified moved-down clauses to the caller's
+	 * restrict_clauses list.  By using list_concat in this order, we leave
+	 * the original list structure of restrict_clauses undamaged.
+	 */
+	*restrict_clauses = list_concat(pclauses, *restrict_clauses);
+
+	/* If we already have a PPI for this parameterization, just return it */
+	if ((ppi = find_param_path_info(joinrel, required_outer)))
+		return ppi;
+
+	/* Estimate the number of rows returned by the parameterized join */
+	rows = get_parameterized_joinrel_size(root, joinrel,
+										  outer_path,
+										  inner_path,
+										  sjinfo,
+										  *restrict_clauses);
+
+	/*
+	 * And now we can build the ParamPathInfo.  No point in saving the
+	 * input-pair-dependent clause list, though.
+	 *
+	 * Note: in GEQO mode, we'll be called in a temporary memory context, but
+	 * the joinrel structure is there too, so no problem.
+	 */
+	ppi = makeNode(ParamPathInfo);
+	ppi->ppi_req_outer = required_outer;
+	ppi->ppi_rows = rows;
+	ppi->ppi_clauses = NIL;
+	joinrel->ppilist = lappend(joinrel->ppilist, ppi);
+
+	return ppi;
+}
+
+/*
+ * get_appendrel_parampathinfo
+ *		Get the ParamPathInfo for a parameterized path for an append relation.
+ *
+ * For an append relation, the rowcount estimate will just be the sum of
+ * the estimates for its children.  However, we still need a ParamPathInfo
+ * to flag the fact that the path requires parameters.  So this just creates
+ * a suitable struct with zero ppi_rows (and no ppi_clauses either, since
+ * the Append node isn't responsible for checking quals).
+ */
+ParamPathInfo *
+get_appendrel_parampathinfo(RelOptInfo *appendrel, Relids required_outer)
+{
+	ParamPathInfo *ppi;
+
+	/* If rel has LATERAL refs, every path for it should account for them */
+	Assert(bms_is_subset(appendrel->lateral_relids, required_outer));
+
+	/* Unparameterized paths have no ParamPathInfo */
+	if (bms_is_empty(required_outer))
+		return NULL;
+
+	Assert(!bms_overlap(appendrel->relids, required_outer));
+
+	/* If we already have a PPI for this parameterization, just return it */
+	if ((ppi = find_param_path_info(appendrel, required_outer)))
+		return ppi;
+
+	/* Else build the ParamPathInfo */
+	ppi = makeNode(ParamPathInfo);
+	ppi->ppi_req_outer = required_outer;
+	ppi->ppi_rows = 0;
+	ppi->ppi_clauses = NIL;
+	appendrel->ppilist = lappend(appendrel->ppilist, ppi);
+
+	return ppi;
+}
+
+/*
+ * Returns a ParamPathInfo for the parameterization given by required_outer, if
+ * already available in the given rel. Returns NULL otherwise.
+ */
+ParamPathInfo *
+find_param_path_info(RelOptInfo *rel, Relids required_outer)
+{
+	ListCell   *lc;
+
+	foreach(lc, rel->ppilist)
+	{
+		ParamPathInfo *ppi = (ParamPathInfo *) lfirst(lc);
+
+		if (bms_equal(ppi->ppi_req_outer, required_outer))
+			return ppi;
+	}
+
+	return NULL;
+}
+
+/*
+ * build_joinrel_partition_info
+ *		Checks if the two relations being joined can use partitionwise join
+ *		and if yes, initialize partitioning information of the resulting
+ *		partitioned join relation.
+ */
+static void
+build_joinrel_partition_info(RelOptInfo *joinrel, RelOptInfo *outer_rel,
+							 RelOptInfo *inner_rel, List *restrictlist,
+							 JoinType jointype)
+{
+	PartitionScheme part_scheme;
+
+	/* Nothing to do if partitionwise join technique is disabled. */
+	if (!enable_partitionwise_join)
+	{
+		Assert(!IS_PARTITIONED_REL(joinrel));
+		return;
+	}
+
+	/*
+	 * We can only consider this join as an input to further partitionwise
+	 * joins if (a) the input relations are partitioned and have
+	 * consider_partitionwise_join=true, (b) the partition schemes match, and
+	 * (c) we can identify an equi-join between the partition keys.  Note that
+	 * if it were possible for have_partkey_equi_join to return different
+	 * answers for the same joinrel depending on which join ordering we try
+	 * first, this logic would break.  That shouldn't happen, though, because
+	 * of the way the query planner deduces implied equalities and reorders
+	 * the joins.  Please see optimizer/README for details.
+	 */
+	if (outer_rel->part_scheme == NULL || inner_rel->part_scheme == NULL ||
+		!outer_rel->consider_partitionwise_join ||
+		!inner_rel->consider_partitionwise_join ||
+		outer_rel->part_scheme != inner_rel->part_scheme ||
+		!have_partkey_equi_join(joinrel, outer_rel, inner_rel,
+								jointype, restrictlist))
+	{
+		Assert(!IS_PARTITIONED_REL(joinrel));
+		return;
+	}
+
+	part_scheme = outer_rel->part_scheme;
+
+	/*
+	 * This function will be called only once for each joinrel, hence it
+	 * should not have partitioning fields filled yet.
+	 */
+	Assert(!joinrel->part_scheme && !joinrel->partexprs &&
+		   !joinrel->nullable_partexprs && !joinrel->part_rels &&
+		   !joinrel->boundinfo);
+
+	/*
+	 * If the join relation is partitioned, it uses the same partitioning
+	 * scheme as the joining relations.
+	 *
+	 * Note: we calculate the partition bounds, number of partitions, and
+	 * child-join relations of the join relation in try_partitionwise_join().
+	 */
+	joinrel->part_scheme = part_scheme;
+	set_joinrel_partition_key_exprs(joinrel, outer_rel, inner_rel, jointype);
+
+	/*
+	 * Set the consider_partitionwise_join flag.
+	 */
+	Assert(outer_rel->consider_partitionwise_join);
+	Assert(inner_rel->consider_partitionwise_join);
+	joinrel->consider_partitionwise_join = true;
+}
+
+/*
+ * have_partkey_equi_join
+ *
+ * Returns true if there exist equi-join conditions involving pairs
+ * of matching partition keys of the relations being joined for all
+ * partition keys.
+ */
+static bool
+have_partkey_equi_join(RelOptInfo *joinrel,
+					   RelOptInfo *rel1, RelOptInfo *rel2,
+					   JoinType jointype, List *restrictlist)
+{
+	PartitionScheme part_scheme = rel1->part_scheme;
+	ListCell   *lc;
+	int			cnt_pks;
+	bool		pk_has_clause[PARTITION_MAX_KEYS];
+	bool		strict_op;
+
+	/*
+	 * This function must only be called when the joined relations have same
+	 * partitioning scheme.
+	 */
+	Assert(rel1->part_scheme == rel2->part_scheme);
+	Assert(part_scheme);
+
+	memset(pk_has_clause, 0, sizeof(pk_has_clause));
+	foreach(lc, restrictlist)
+	{
+		RestrictInfo *rinfo = lfirst_node(RestrictInfo, lc);
+		OpExpr	   *opexpr;
+		Expr	   *expr1;
+		Expr	   *expr2;
+		int			ipk1;
+		int			ipk2;
+
+		/* If processing an outer join, only use its own join clauses. */
+		if (IS_OUTER_JOIN(jointype) &&
+			RINFO_IS_PUSHED_DOWN(rinfo, joinrel->relids))
+			continue;
+
+		/* Skip clauses which can not be used for a join. */
+		if (!rinfo->can_join)
+			continue;
+
+		/* Skip clauses which are not equality conditions. */
+		if (!rinfo->mergeopfamilies && !OidIsValid(rinfo->hashjoinoperator))
+			continue;
+
+		/* Should be OK to assume it's an OpExpr. */
+		opexpr = castNode(OpExpr, rinfo->clause);
+
+		/* Match the operands to the relation. */
+		if (bms_is_subset(rinfo->left_relids, rel1->relids) &&
+			bms_is_subset(rinfo->right_relids, rel2->relids))
+		{
+			expr1 = linitial(opexpr->args);
+			expr2 = lsecond(opexpr->args);
+		}
+		else if (bms_is_subset(rinfo->left_relids, rel2->relids) &&
+				 bms_is_subset(rinfo->right_relids, rel1->relids))
+		{
+			expr1 = lsecond(opexpr->args);
+			expr2 = linitial(opexpr->args);
+		}
+		else
+			continue;
+
+		/*
+		 * Now we need to know whether the join operator is strict; see
+		 * comments in pathnodes.h.
+		 */
+		strict_op = op_strict(opexpr->opno);
+
+		/*
+		 * Only clauses referencing the partition keys are useful for
+		 * partitionwise join.
+		 */
+		ipk1 = match_expr_to_partition_keys(expr1, rel1, strict_op);
+		if (ipk1 < 0)
+			continue;
+		ipk2 = match_expr_to_partition_keys(expr2, rel2, strict_op);
+		if (ipk2 < 0)
+			continue;
+
+		/*
+		 * If the clause refers to keys at different ordinal positions, it can
+		 * not be used for partitionwise join.
+		 */
+		if (ipk1 != ipk2)
+			continue;
+
+		/*
+		 * The clause allows partitionwise join only if it uses the same
+		 * operator family as that specified by the partition key.
+		 */
+		if (rel1->part_scheme->strategy == PARTITION_STRATEGY_HASH)
+		{
+			if (!OidIsValid(rinfo->hashjoinoperator) ||
+				!op_in_opfamily(rinfo->hashjoinoperator,
+								part_scheme->partopfamily[ipk1]))
+				continue;
+		}
+		else if (!list_member_oid(rinfo->mergeopfamilies,
+								  part_scheme->partopfamily[ipk1]))
+			continue;
+
+		/* Mark the partition key as having an equi-join clause. */
+		pk_has_clause[ipk1] = true;
+	}
+
+	/* Check whether every partition key has an equi-join condition. */
+	for (cnt_pks = 0; cnt_pks < part_scheme->partnatts; cnt_pks++)
+	{
+		if (!pk_has_clause[cnt_pks])
+			return false;
+	}
+
+	return true;
+}
+
+/*
+ * match_expr_to_partition_keys
+ *
+ * Tries to match an expression to one of the nullable or non-nullable
+ * partition keys of "rel".  Returns the matched key's ordinal position,
+ * or -1 if the expression could not be matched to any of the keys.
+ *
+ * strict_op must be true if the expression will be compared with the
+ * partition key using a strict operator.  This allows us to consider
+ * nullable as well as nonnullable partition keys.
+ */
+static int
+match_expr_to_partition_keys(Expr *expr, RelOptInfo *rel, bool strict_op)
+{
+	int			cnt;
+
+	/* This function should be called only for partitioned relations. */
+	Assert(rel->part_scheme);
+	Assert(rel->partexprs);
+	Assert(rel->nullable_partexprs);
+
+	/* Remove any relabel decorations. */
+	while (IsA(expr, RelabelType))
+		expr = (Expr *) (castNode(RelabelType, expr))->arg;
+
+	for (cnt = 0; cnt < rel->part_scheme->partnatts; cnt++)
+	{
+		ListCell   *lc;
+
+		/* We can always match to the non-nullable partition keys. */
+		foreach(lc, rel->partexprs[cnt])
+		{
+			if (equal(lfirst(lc), expr))
+				return cnt;
+		}
+
+		if (!strict_op)
+			continue;
+
+		/*
+		 * If it's a strict join operator then a NULL partition key on one
+		 * side will not join to any partition key on the other side, and in
+		 * particular such a row can't join to a row from a different
+		 * partition on the other side.  So, it's okay to search the nullable
+		 * partition keys as well.
+		 */
+		foreach(lc, rel->nullable_partexprs[cnt])
+		{
+			if (equal(lfirst(lc), expr))
+				return cnt;
+		}
+	}
+
+	return -1;
+}
+
+/*
+ * set_joinrel_partition_key_exprs
+ *		Initialize partition key expressions for a partitioned joinrel.
+ */
+static void
+set_joinrel_partition_key_exprs(RelOptInfo *joinrel,
+								RelOptInfo *outer_rel, RelOptInfo *inner_rel,
+								JoinType jointype)
+{
+	PartitionScheme part_scheme = joinrel->part_scheme;
+	int			partnatts = part_scheme->partnatts;
+
+	joinrel->partexprs = (List **) palloc0(sizeof(List *) * partnatts);
+	joinrel->nullable_partexprs =
+		(List **) palloc0(sizeof(List *) * partnatts);
+
+	/*
+	 * The joinrel's partition expressions are the same as those of the input
+	 * rels, but we must properly classify them as nullable or not in the
+	 * joinrel's output.  (Also, we add some more partition expressions if
+	 * it's a FULL JOIN.)
+	 */
+	for (int cnt = 0; cnt < partnatts; cnt++)
+	{
+		/* mark these const to enforce that we copy them properly */
+		const List *outer_expr = outer_rel->partexprs[cnt];
+		const List *outer_null_expr = outer_rel->nullable_partexprs[cnt];
+		const List *inner_expr = inner_rel->partexprs[cnt];
+		const List *inner_null_expr = inner_rel->nullable_partexprs[cnt];
+		List	   *partexpr = NIL;
+		List	   *nullable_partexpr = NIL;
+		ListCell   *lc;
+
+		switch (jointype)
+		{
+				/*
+				 * A join relation resulting from an INNER join may be
+				 * regarded as partitioned by either of the inner and outer
+				 * relation keys.  For example, A INNER JOIN B ON A.a = B.b
+				 * can be regarded as partitioned on either A.a or B.b.  So we
+				 * add both keys to the joinrel's partexpr lists.  However,
+				 * anything that was already nullable still has to be treated
+				 * as nullable.
+				 */
+			case JOIN_INNER:
+				partexpr = list_concat_copy(outer_expr, inner_expr);
+				nullable_partexpr = list_concat_copy(outer_null_expr,
+													 inner_null_expr);
+				break;
+
+				/*
+				 * A join relation resulting from a SEMI or ANTI join may be
+				 * regarded as partitioned by the outer relation keys.  The
+				 * inner relation's keys are no longer interesting; since they
+				 * aren't visible in the join output, nothing could join to
+				 * them.
+				 */
+			case JOIN_SEMI:
+			case JOIN_ANTI:
+				partexpr = list_copy(outer_expr);
+				nullable_partexpr = list_copy(outer_null_expr);
+				break;
+
+				/*
+				 * A join relation resulting from a LEFT OUTER JOIN likewise
+				 * may be regarded as partitioned on the (non-nullable) outer
+				 * relation keys.  The inner (nullable) relation keys are okay
+				 * as partition keys for further joins as long as they involve
+				 * strict join operators.
+				 */
+			case JOIN_LEFT:
+				partexpr = list_copy(outer_expr);
+				nullable_partexpr = list_concat_copy(inner_expr,
+													 outer_null_expr);
+				nullable_partexpr = list_concat(nullable_partexpr,
+												inner_null_expr);
+				break;
+
+				/*
+				 * For FULL OUTER JOINs, both relations are nullable, so the
+				 * resulting join relation may be regarded as partitioned on
+				 * either of inner and outer relation keys, but only for joins
+				 * that involve strict join operators.
+				 */
+			case JOIN_FULL:
+				nullable_partexpr = list_concat_copy(outer_expr,
+													 inner_expr);
+				nullable_partexpr = list_concat(nullable_partexpr,
+												outer_null_expr);
+				nullable_partexpr = list_concat(nullable_partexpr,
+												inner_null_expr);
+
+				/*
+				 * Also add CoalesceExprs corresponding to each possible
+				 * full-join output variable (that is, left side coalesced to
+				 * right side), so that we can match equijoin expressions
+				 * using those variables.  We really only need these for
+				 * columns merged by JOIN USING, and only with the pairs of
+				 * input items that correspond to the data structures that
+				 * parse analysis would build for such variables.  But it's
+				 * hard to tell which those are, so just make all the pairs.
+				 * Extra items in the nullable_partexprs list won't cause big
+				 * problems.  (It's possible that such items will get matched
+				 * to user-written COALESCEs, but it should still be valid to
+				 * partition on those, since they're going to be either the
+				 * partition column or NULL; it's the same argument as for
+				 * partitionwise nesting of any outer join.)  We assume no
+				 * type coercions are needed to make the coalesce expressions,
+				 * since columns of different types won't have gotten
+				 * classified as the same PartitionScheme.
+				 */
+				foreach(lc, list_concat_copy(outer_expr, outer_null_expr))
+				{
+					Node	   *larg = (Node *) lfirst(lc);
+					ListCell   *lc2;
+
+					foreach(lc2, list_concat_copy(inner_expr, inner_null_expr))
+					{
+						Node	   *rarg = (Node *) lfirst(lc2);
+						CoalesceExpr *c = makeNode(CoalesceExpr);
+
+						c->coalescetype = exprType(larg);
+						c->coalescecollid = exprCollation(larg);
+						c->args = list_make2(larg, rarg);
+						c->location = -1;
+						nullable_partexpr = lappend(nullable_partexpr, c);
+					}
+				}
+				break;
+
+			default:
+				elog(ERROR, "unrecognized join type: %d", (int) jointype);
+		}
+
+		joinrel->partexprs[cnt] = partexpr;
+		joinrel->nullable_partexprs[cnt] = nullable_partexpr;
+	}
+}
+
+/*
+ * build_child_join_reltarget
+ *	  Set up a child-join relation's reltarget from a parent-join relation.
+ */
+static void
+build_child_join_reltarget(PlannerInfo *root,
+						   RelOptInfo *parentrel,
+						   RelOptInfo *childrel,
+						   int nappinfos,
+						   AppendRelInfo **appinfos)
+{
+	/* Build the targetlist */
+	childrel->reltarget->exprs = (List *)
+		adjust_appendrel_attrs(root,
+							   (Node *) parentrel->reltarget->exprs,
+							   nappinfos, appinfos);
+
+	/* Set the cost and width fields */
+	childrel->reltarget->cost.startup = parentrel->reltarget->cost.startup;
+	childrel->reltarget->cost.per_tuple = parentrel->reltarget->cost.per_tuple;
+	childrel->reltarget->width = parentrel->reltarget->width;
+}