v19-rebased.txt

text/plain

Filename: v19-rebased.txt
Type: text/plain
Part: 6
Message: Re: [PoC] Reducing planning time when tables have many partitions
diff --git a/contrib/postgres_fdw/postgres_fdw.c b/contrib/postgres_fdw/postgres_fdw.c
index b92e2a0fc9f..4d563c58bdc 100644
--- a/contrib/postgres_fdw/postgres_fdw.c
+++ b/contrib/postgres_fdw/postgres_fdw.c
@@ -7770,6 +7770,10 @@ conversion_error_callback(void *arg)
 				varno = var->varno;
 				colno = var->varattno;
 			}
+			/*
+			 * XXX why don't we break here? Surely there can't be another
+			 * equal EquivalenceMember?
+			 */
 		}
 
 		if (varno > 0)
@@ -7828,26 +7832,29 @@ conversion_error_callback(void *arg)
 EquivalenceMember *
 find_em_for_rel(PlannerInfo *root, EquivalenceClass *ec, RelOptInfo *rel)
 {
-	ListCell   *lc;
-
+	EquivalenceMemberIterator iter;
+	EquivalenceMember *em;
 	PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) rel->fdw_private;
 
-	foreach(lc, ec->ec_members)
-	{
-		EquivalenceMember *em = (EquivalenceMember *) lfirst(lc);
+	setup_eclass_member_iterator(&iter, root, ec, rel->relids, true, false);
 
+	while ((em = eclass_member_iterator_next(&iter)) != NULL)
+	{
 		/*
 		 * Note we require !bms_is_empty, else we'd accept constant
 		 * expressions which are not suitable for the purpose.
 		 */
+		Assert(!bms_is_empty(em->em_relids));
+
 		if (bms_is_subset(em->em_relids, rel->relids) &&
-			!bms_is_empty(em->em_relids) &&
 			bms_is_empty(bms_intersect(em->em_relids, fpinfo->hidden_subquery_rels)) &&
 			is_foreign_expr(root, rel, em->em_expr))
-			return em;
+			break;
 	}
 
-	return NULL;
+	eclass_member_iterator_dispose(&iter);
+
+	return em;
 }
 
 /*
@@ -7874,7 +7881,9 @@ find_em_for_rel_target(PlannerInfo *root, EquivalenceClass *ec,
 	{
 		Expr	   *expr = (Expr *) lfirst(lc1);
 		Index		sgref = get_pathtarget_sortgroupref(target, i);
-		ListCell   *lc2;
+		EquivalenceMemberIterator iter;
+		EquivalenceMember *em;
+		Relids		expr_relids;
 
 		/* Ignore non-sort expressions */
 		if (sgref == 0 ||
@@ -7889,19 +7898,20 @@ find_em_for_rel_target(PlannerInfo *root, EquivalenceClass *ec,
 		while (expr && IsA(expr, RelabelType))
 			expr = ((RelabelType *) expr)->arg;
 
+		expr_relids = pull_varnos(root, (Node *) expr);
+		setup_eclass_member_strict_iterator(&iter, root, ec, expr_relids,
+											false, false);
+
 		/* Locate an EquivalenceClass member matching this expr, if any */
-		foreach(lc2, ec->ec_members)
+		while ((em = eclass_member_iterator_strict_next(&iter)) != NULL)
 		{
-			EquivalenceMember *em = (EquivalenceMember *) lfirst(lc2);
 			Expr	   *em_expr;
 
-			/* Don't match constants */
-			if (em->em_is_const)
-				continue;
+			/* don't expect constants */
+			Assert(!em->em_is_const);
 
-			/* Ignore child members */
-			if (em->em_is_child)
-				continue;
+			/* don't expect child members */
+			Assert(!em->em_is_child);
 
 			/* Match if same expression (after stripping relabel) */
 			em_expr = em->em_expr;
@@ -7913,10 +7923,15 @@ find_em_for_rel_target(PlannerInfo *root, EquivalenceClass *ec,
 
 			/* Check that expression (including relabels!) is shippable */
 			if (is_foreign_expr(root, rel, em->em_expr))
+			{
+				bms_free(expr_relids);
+				eclass_member_iterator_dispose(&iter);
 				return em;
+			}
 		}
-
 		i++;
+		bms_free(expr_relids);
+		eclass_member_iterator_dispose(&iter);
 	}
 
 	return NULL;
diff --git a/src/backend/nodes/list.c b/src/backend/nodes/list.c
index 1597b8e8127..d093871427d 100644
--- a/src/backend/nodes/list.c
+++ b/src/backend/nodes/list.c
@@ -1684,6 +1684,22 @@ list_sort(List *list, list_sort_comparator cmp)
 		qsort(list->elements, len, sizeof(ListCell), (qsort_comparator) cmp);
 }
 
+/*
+ * list_sort comparator for sorting a list into ascending ptr order.
+ */
+int
+list_ptr_cmp(const ListCell *p1, const ListCell *p2)
+{
+	void	   *v1 = lfirst(p1);
+	void	   *v2 = lfirst(p2);
+
+	if (v1 < v2)
+		return -1;
+	if (v1 > v2)
+		return 1;
+	return 0;
+}
+
 /*
  * list_sort comparator for sorting a list into ascending int order.
  */
diff --git a/src/backend/nodes/outfuncs.c b/src/backend/nodes/outfuncs.c
index bb9bdd67192..94ce706c6c9 100644
--- a/src/backend/nodes/outfuncs.c
+++ b/src/backend/nodes/outfuncs.c
@@ -466,8 +466,11 @@ _outEquivalenceClass(StringInfo str, const EquivalenceClass *node)
 	WRITE_NODE_FIELD(ec_opfamilies);
 	WRITE_OID_FIELD(ec_collation);
 	WRITE_NODE_FIELD(ec_members);
-	WRITE_NODE_FIELD(ec_sources);
-	WRITE_NODE_FIELD(ec_derives);
+	WRITE_BITMAPSET_FIELD(ec_member_indexes);
+	WRITE_BITMAPSET_FIELD(ec_nonchild_indexes);
+	WRITE_BITMAPSET_FIELD(ec_norel_indexes);
+	WRITE_BITMAPSET_FIELD(ec_source_indexes);
+	WRITE_BITMAPSET_FIELD(ec_derive_indexes);
 	WRITE_BITMAPSET_FIELD(ec_relids);
 	WRITE_BOOL_FIELD(ec_has_const);
 	WRITE_BOOL_FIELD(ec_has_volatile);
@@ -573,6 +576,9 @@ _outRangeTblEntry(StringInfo str, const RangeTblEntry *node)
 	WRITE_BOOL_FIELD(lateral);
 	WRITE_BOOL_FIELD(inFromCl);
 	WRITE_NODE_FIELD(securityQuals);
+	WRITE_BITMAPSET_FIELD(eclass_member_indexes);
+	WRITE_BITMAPSET_FIELD(eclass_source_indexes);
+	WRITE_BITMAPSET_FIELD(eclass_derive_indexes);
 }
 
 static void
diff --git a/src/backend/nodes/readfuncs.c b/src/backend/nodes/readfuncs.c
index 64d3a09f765..78960e4f475 100644
--- a/src/backend/nodes/readfuncs.c
+++ b/src/backend/nodes/readfuncs.c
@@ -434,6 +434,9 @@ _readRangeTblEntry(void)
 	READ_BOOL_FIELD(lateral);
 	READ_BOOL_FIELD(inFromCl);
 	READ_NODE_FIELD(securityQuals);
+	READ_BITMAPSET_FIELD(eclass_member_indexes);
+	READ_BITMAPSET_FIELD(eclass_source_indexes);
+	READ_BITMAPSET_FIELD(eclass_derive_indexes);
 
 	READ_DONE();
 }
diff --git a/src/backend/optimizer/path/costsize.c b/src/backend/optimizer/path/costsize.c
index ec004ed9493..bac2252eb91 100644
--- a/src/backend/optimizer/path/costsize.c
+++ b/src/backend/optimizer/path/costsize.c
@@ -5839,7 +5839,8 @@ get_foreign_key_join_selectivity(PlannerInfo *root,
 				if (ec && ec->ec_has_const)
 				{
 					EquivalenceMember *em = fkinfo->fk_eclass_member[i];
-					RestrictInfo *rinfo = find_derived_clause_for_ec_member(ec,
+					RestrictInfo *rinfo = find_derived_clause_for_ec_member(root,
+																			ec,
 																			em);
 
 					if (rinfo)
diff --git a/src/backend/optimizer/path/equivclass.c b/src/backend/optimizer/path/equivclass.c
index 7cafaca33c5..ec4669c23bf 100644
--- a/src/backend/optimizer/path/equivclass.c
+++ b/src/backend/optimizer/path/equivclass.c
@@ -32,8 +32,12 @@
 #include "rewrite/rewriteManip.h"
 #include "utils/lsyscache.h"
 
-
-static EquivalenceMember *add_eq_member(EquivalenceClass *ec,
+static void add_eq_source(PlannerInfo *root, EquivalenceClass *ec,
+						  RestrictInfo *rinfo);
+static void add_eq_derive(PlannerInfo *root, EquivalenceClass *ec,
+						  RestrictInfo *rinfo);
+static EquivalenceMember *add_eq_member(PlannerInfo *root,
+										EquivalenceClass *ec,
 										Expr *expr, Relids relids,
 										JoinDomain *jdomain,
 										EquivalenceMember *parent,
@@ -310,7 +314,6 @@ process_equivalence(PlannerInfo *root,
 		/* If case 1, nothing to do, except add to sources */
 		if (ec1 == ec2)
 		{
-			ec1->ec_sources = lappend(ec1->ec_sources, restrictinfo);
 			ec1->ec_min_security = Min(ec1->ec_min_security,
 									   restrictinfo->security_level);
 			ec1->ec_max_security = Max(ec1->ec_max_security,
@@ -321,6 +324,8 @@ process_equivalence(PlannerInfo *root,
 			/* mark the RI as usable with this pair of EMs */
 			restrictinfo->left_em = em1;
 			restrictinfo->right_em = em2;
+
+			add_eq_source(root, ec1, restrictinfo);
 			return true;
 		}
 
@@ -341,8 +346,16 @@ process_equivalence(PlannerInfo *root,
 		 * be found.
 		 */
 		ec1->ec_members = list_concat(ec1->ec_members, ec2->ec_members);
-		ec1->ec_sources = list_concat(ec1->ec_sources, ec2->ec_sources);
-		ec1->ec_derives = list_concat(ec1->ec_derives, ec2->ec_derives);
+		ec1->ec_member_indexes = bms_add_members(ec1->ec_member_indexes,
+												 ec2->ec_member_indexes);
+		ec1->ec_nonchild_indexes = bms_add_members(ec1->ec_nonchild_indexes,
+												   ec2->ec_nonchild_indexes);
+		ec1->ec_norel_indexes = bms_add_members(ec1->ec_norel_indexes,
+												ec2->ec_norel_indexes);
+		ec1->ec_source_indexes = bms_join(ec1->ec_source_indexes,
+										  ec2->ec_source_indexes);
+		ec1->ec_derive_indexes = bms_join(ec1->ec_derive_indexes,
+										  ec2->ec_derive_indexes);
 		ec1->ec_relids = bms_join(ec1->ec_relids, ec2->ec_relids);
 		ec1->ec_has_const |= ec2->ec_has_const;
 		/* can't need to set has_volatile */
@@ -354,10 +367,12 @@ process_equivalence(PlannerInfo *root,
 		root->eq_classes = list_delete_nth_cell(root->eq_classes, ec2_idx);
 		/* just to avoid debugging confusion w/ dangling pointers: */
 		ec2->ec_members = NIL;
-		ec2->ec_sources = NIL;
-		ec2->ec_derives = NIL;
+		ec2->ec_member_indexes = NULL;
+		ec2->ec_nonchild_indexes = NULL;
+		ec2->ec_norel_indexes = NULL;
+		ec2->ec_source_indexes = NULL;
+		ec2->ec_derive_indexes = NULL;
 		ec2->ec_relids = NULL;
-		ec1->ec_sources = lappend(ec1->ec_sources, restrictinfo);
 		ec1->ec_min_security = Min(ec1->ec_min_security,
 								   restrictinfo->security_level);
 		ec1->ec_max_security = Max(ec1->ec_max_security,
@@ -368,13 +383,14 @@ process_equivalence(PlannerInfo *root,
 		/* mark the RI as usable with this pair of EMs */
 		restrictinfo->left_em = em1;
 		restrictinfo->right_em = em2;
+
+		add_eq_source(root, ec1, restrictinfo);
 	}
 	else if (ec1)
 	{
 		/* Case 3: add item2 to ec1 */
-		em2 = add_eq_member(ec1, item2, item2_relids,
+		em2 = add_eq_member(root, ec1, item2, item2_relids,
 							jdomain, NULL, item2_type);
-		ec1->ec_sources = lappend(ec1->ec_sources, restrictinfo);
 		ec1->ec_min_security = Min(ec1->ec_min_security,
 								   restrictinfo->security_level);
 		ec1->ec_max_security = Max(ec1->ec_max_security,
@@ -385,13 +401,14 @@ process_equivalence(PlannerInfo *root,
 		/* mark the RI as usable with this pair of EMs */
 		restrictinfo->left_em = em1;
 		restrictinfo->right_em = em2;
+
+		add_eq_source(root, ec1, restrictinfo);
 	}
 	else if (ec2)
 	{
 		/* Case 3: add item1 to ec2 */
-		em1 = add_eq_member(ec2, item1, item1_relids,
+		em1 = add_eq_member(root, ec2, item1, item1_relids,
 							jdomain, NULL, item1_type);
-		ec2->ec_sources = lappend(ec2->ec_sources, restrictinfo);
 		ec2->ec_min_security = Min(ec2->ec_min_security,
 								   restrictinfo->security_level);
 		ec2->ec_max_security = Max(ec2->ec_max_security,
@@ -402,6 +419,8 @@ process_equivalence(PlannerInfo *root,
 		/* mark the RI as usable with this pair of EMs */
 		restrictinfo->left_em = em1;
 		restrictinfo->right_em = em2;
+
+		add_eq_source(root, ec2, restrictinfo);
 	}
 	else
 	{
@@ -411,8 +430,11 @@ process_equivalence(PlannerInfo *root,
 		ec->ec_opfamilies = opfamilies;
 		ec->ec_collation = collation;
 		ec->ec_members = NIL;
-		ec->ec_sources = list_make1(restrictinfo);
-		ec->ec_derives = NIL;
+		ec->ec_member_indexes = NULL;
+		ec->ec_nonchild_indexes = NULL;
+		ec->ec_norel_indexes = NULL;
+		ec->ec_source_indexes = NULL;
+		ec->ec_derive_indexes = NULL;
 		ec->ec_relids = NULL;
 		ec->ec_has_const = false;
 		ec->ec_has_volatile = false;
@@ -421,9 +443,9 @@ process_equivalence(PlannerInfo *root,
 		ec->ec_min_security = restrictinfo->security_level;
 		ec->ec_max_security = restrictinfo->security_level;
 		ec->ec_merged = NULL;
-		em1 = add_eq_member(ec, item1, item1_relids,
+		em1 = add_eq_member(root, ec, item1, item1_relids,
 							jdomain, NULL, item1_type);
-		em2 = add_eq_member(ec, item2, item2_relids,
+		em2 = add_eq_member(root, ec, item2, item2_relids,
 							jdomain, NULL, item2_type);
 
 		root->eq_classes = lappend(root->eq_classes, ec);
@@ -434,6 +456,8 @@ process_equivalence(PlannerInfo *root,
 		/* mark the RI as usable with this pair of EMs */
 		restrictinfo->left_em = em1;
 		restrictinfo->right_em = em2;
+
+		add_eq_source(root, ec, restrictinfo);
 	}
 
 	return true;
@@ -509,16 +533,64 @@ canonicalize_ec_expression(Expr *expr, Oid req_type, Oid req_collation)
 	return expr;
 }
 
+/*
+ * add_eq_source - add 'rinfo' in eq_sources for this 'ec'
+ */
+static void
+add_eq_source(PlannerInfo *root, EquivalenceClass *ec, RestrictInfo *rinfo)
+{
+	int			source_idx = list_length(root->eq_sources);
+	int			i;
+
+	ec->ec_source_indexes = bms_add_member(ec->ec_source_indexes, source_idx);
+	root->eq_sources = lappend(root->eq_sources, rinfo);
+
+	i = -1;
+	while ((i = bms_next_member(rinfo->clause_relids, i)) >= 0)
+	{
+		RangeTblEntry *rte = root->simple_rte_array[i];
+
+		rte->eclass_source_indexes = bms_add_member(rte->eclass_source_indexes,
+													source_idx);
+	}
+}
+
+/*
+ * add_eq_derive - add 'rinfo' in eq_derives for this 'ec'
+ */
+static void
+add_eq_derive(PlannerInfo *root, EquivalenceClass *ec, RestrictInfo *rinfo)
+{
+	int			derive_idx = list_length(root->eq_derives);
+	int			i;
+
+	ec->ec_derive_indexes = bms_add_member(ec->ec_derive_indexes, derive_idx);
+	root->eq_derives = lappend(root->eq_derives, rinfo);
+
+	i = -1;
+	while ((i = bms_next_member(rinfo->clause_relids, i)) >= 0)
+	{
+		RangeTblEntry *rte = root->simple_rte_array[i];
+
+		rte->eclass_derive_indexes = bms_add_member(rte->eclass_derive_indexes,
+													derive_idx);
+	}
+}
+
 /*
  * add_eq_member - build a new EquivalenceMember and add it to an EC
  */
 static EquivalenceMember *
-add_eq_member(EquivalenceClass *ec, Expr *expr, Relids relids,
+add_eq_member(PlannerInfo *root, EquivalenceClass *ec, Expr *expr, Relids relids,
 			  JoinDomain *jdomain, EquivalenceMember *parent, Oid datatype)
 {
 	EquivalenceMember *em = makeNode(EquivalenceMember);
+	Relids		expr_relids;
+	int			em_index = list_length(root->eq_members);
+	int			i;
 
 	em->em_expr = expr;
+	em->em_index = em_index;
 	em->em_relids = relids;
 	em->em_is_const = false;
 	em->em_is_child = (parent != NULL);
@@ -526,6 +598,23 @@ add_eq_member(EquivalenceClass *ec, Expr *expr, Relids relids,
 	em->em_jdomain = jdomain;
 	em->em_parent = parent;
 
+	/*
+	 * We must determine the exact set of relids in the expr for child
+	 * EquivalenceMembers as what is given to us in 'relids' may differ from
+	 * the relids mentioned in the expression.  See add_child_rel_equivalences
+	 */
+	if (parent != NULL)
+		expr_relids = pull_varnos(root, (Node *) expr);
+	else
+	{
+		expr_relids = relids;
+		/* We expect the relids to match for non-child members */
+		Assert(bms_equal(pull_varnos(root, (Node *) expr), relids));
+	}
+
+	/* record the actual relids from 'expr' */
+	em->em_norel_expr = bms_is_empty(expr_relids);
+
 	if (bms_is_empty(relids))
 	{
 		/*
@@ -544,9 +633,32 @@ add_eq_member(EquivalenceClass *ec, Expr *expr, Relids relids,
 	else if (!parent)			/* child members don't add to ec_relids */
 	{
 		ec->ec_relids = bms_add_members(ec->ec_relids, relids);
+		ec->ec_nonchild_indexes = bms_add_member(ec->ec_nonchild_indexes, em_index);
 	}
+
+	/* add the new member to the list */
 	ec->ec_members = lappend(ec->ec_members, em);
 
+	/* and add it to the index and PlannerInfo's list */
+	ec->ec_member_indexes = bms_add_member(ec->ec_member_indexes, em_index);
+	root->eq_members = lappend(root->eq_members, em);
+
+	/* record exprs with no relids */
+	if (bms_is_empty(expr_relids))
+		ec->ec_norel_indexes = bms_add_member(ec->ec_norel_indexes, em_index);
+
+	if (parent != NULL)
+		expr_relids = bms_add_members(expr_relids, relids);
+
+	i = -1;
+	while ((i = bms_next_member(expr_relids, i)) >= 0)
+	{
+		RangeTblEntry *rte = root->simple_rte_array[i];
+
+		rte->eclass_member_indexes =
+			bms_add_member(rte->eclass_member_indexes, em_index);
+	}
+
 	return em;
 }
 
@@ -603,6 +715,7 @@ get_eclass_for_sort_expr(PlannerInfo *root,
 	 * Ensure the expression exposes the correct type and collation.
 	 */
 	expr = canonicalize_ec_expression(expr, opcintype, collation);
+	expr_relids = pull_varnos(root, (Node *) expr);
 
 	/*
 	 * Since SortGroupClause nodes are top-level expressions (GROUP BY, ORDER
@@ -616,7 +729,8 @@ get_eclass_for_sort_expr(PlannerInfo *root,
 	foreach(lc1, root->eq_classes)
 	{
 		EquivalenceClass *cur_ec = (EquivalenceClass *) lfirst(lc1);
-		ListCell   *lc2;
+		EquivalenceMemberIterator iter;
+		EquivalenceMember *cur_em;
 
 		/*
 		 * Never match to a volatile EC, except when we are looking at another
@@ -631,10 +745,11 @@ get_eclass_for_sort_expr(PlannerInfo *root,
 		if (!equal(opfamilies, cur_ec->ec_opfamilies))
 			continue;
 
-		foreach(lc2, cur_ec->ec_members)
-		{
-			EquivalenceMember *cur_em = (EquivalenceMember *) lfirst(lc2);
+		setup_eclass_member_strict_iterator(&iter, root, cur_ec, expr_relids,
+											true, true);
 
+		while ((cur_em = eclass_member_iterator_strict_next(&iter)) != NULL)
+		{
 			/*
 			 * Ignore child members unless they match the request.
 			 */
@@ -653,6 +768,8 @@ get_eclass_for_sort_expr(PlannerInfo *root,
 				equal(expr, cur_em->em_expr))
 				return cur_ec;	/* Match! */
 		}
+
+		eclass_member_iterator_dispose(&iter);
 	}
 
 	/* No match; does caller want a NULL result? */
@@ -670,8 +787,11 @@ get_eclass_for_sort_expr(PlannerInfo *root,
 	newec->ec_opfamilies = list_copy(opfamilies);
 	newec->ec_collation = collation;
 	newec->ec_members = NIL;
-	newec->ec_sources = NIL;
-	newec->ec_derives = NIL;
+	newec->ec_member_indexes = NULL;
+	newec->ec_nonchild_indexes = NULL;
+	newec->ec_norel_indexes = NULL;
+	newec->ec_source_indexes = NULL;
+	newec->ec_derive_indexes = NULL;
 	newec->ec_relids = NULL;
 	newec->ec_has_const = false;
 	newec->ec_has_volatile = contain_volatile_functions((Node *) expr);
@@ -684,12 +804,7 @@ get_eclass_for_sort_expr(PlannerInfo *root,
 	if (newec->ec_has_volatile && sortref == 0) /* should not happen */
 		elog(ERROR, "volatile EquivalenceClass has no sortref");
 
-	/*
-	 * Get the precise set of relids appearing in the expression.
-	 */
-	expr_relids = pull_varnos(root, (Node *) expr);
-
-	newem = add_eq_member(newec, copyObject(expr), expr_relids,
+	newem = add_eq_member(root, newec, copyObject(expr), expr_relids,
 						  jdomain, NULL, opcintype);
 
 	/*
@@ -721,7 +836,7 @@ get_eclass_for_sort_expr(PlannerInfo *root,
 		int			ec_index = list_length(root->eq_classes) - 1;
 		int			i = -1;
 
-		while ((i = bms_next_member(newec->ec_relids, i)) > 0)
+		while ((i = bms_next_member(newec->ec_relids, i)) >= 0)
 		{
 			RelOptInfo *rel = root->simple_rel_array[i];
 
@@ -731,7 +846,7 @@ get_eclass_for_sort_expr(PlannerInfo *root,
 
 			if (rel == NULL)	/* must be an outer join */
 			{
-				Assert(bms_is_member(i, root->outer_join_rels));
+				Assert(i == 0 || bms_is_member(i, root->outer_join_rels));
 				continue;
 			}
 
@@ -760,19 +875,25 @@ get_eclass_for_sort_expr(PlannerInfo *root,
  * Child EC members are ignored unless they belong to given 'relids'.
  */
 EquivalenceMember *
-find_ec_member_matching_expr(EquivalenceClass *ec,
+find_ec_member_matching_expr(PlannerInfo *root,
+							 EquivalenceClass *ec,
 							 Expr *expr,
 							 Relids relids)
 {
-	ListCell   *lc;
+	EquivalenceMemberIterator iter;
+	Relids		expr_relids;
+	EquivalenceMember *em;
 
 	/* We ignore binary-compatible relabeling on both ends */
 	while (expr && IsA(expr, RelabelType))
 		expr = ((RelabelType *) expr)->arg;
 
-	foreach(lc, ec->ec_members)
+	expr_relids = pull_varnos(root, (Node *) expr);
+	setup_eclass_member_strict_iterator(&iter, root, ec, expr_relids, true,
+										true);
+
+	while ((em = eclass_member_iterator_strict_next(&iter)) != NULL)
 	{
-		EquivalenceMember *em = (EquivalenceMember *) lfirst(lc);
 		Expr	   *emexpr;
 
 		/*
@@ -797,10 +918,13 @@ find_ec_member_matching_expr(EquivalenceClass *ec,
 			emexpr = ((RelabelType *) emexpr)->arg;
 
 		if (equal(emexpr, expr))
-			return em;
+			break;
 	}
 
-	return NULL;
+	bms_free(expr_relids);
+	eclass_member_iterator_dispose(&iter);
+
+	return em;
 }
 
 /*
@@ -938,7 +1062,7 @@ relation_can_be_sorted_early(PlannerInfo *root, RelOptInfo *rel,
 	{
 		Expr	   *targetexpr = (Expr *) lfirst(lc);
 
-		em = find_ec_member_matching_expr(ec, targetexpr, rel->relids);
+		em = find_ec_member_matching_expr(root, ec, targetexpr, rel->relids);
 		if (!em)
 			continue;
 
@@ -1025,7 +1149,7 @@ relation_can_be_sorted_early(PlannerInfo *root, RelOptInfo *rel,
  * scanning of the quals and before Path construction begins.
  *
  * We make no attempt to avoid generating duplicate RestrictInfos here: we
- * don't search ec_sources or ec_derives for matches.  It doesn't really
+ * don't search eq_sources or eq_derives for matches.  It doesn't really
  * seem worth the trouble to do so.
  */
 void
@@ -1082,7 +1206,7 @@ generate_base_implied_equalities(PlannerInfo *root)
 		 * this is a cheap version of has_relevant_eclass_joinclause().
 		 */
 		i = -1;
-		while ((i = bms_next_member(ec->ec_relids, i)) > 0)
+		while ((i = bms_next_member(ec->ec_relids, i)) >= 0)
 		{
 			RelOptInfo *rel = root->simple_rel_array[i];
 
@@ -1118,6 +1242,7 @@ generate_base_implied_equalities_const(PlannerInfo *root,
 {
 	EquivalenceMember *const_em = NULL;
 	ListCell   *lc;
+	int			i;
 
 	/*
 	 * In the trivial case where we just had one "var = const" clause, push
@@ -1127,9 +1252,9 @@ generate_base_implied_equalities_const(PlannerInfo *root,
 	 * equivalent to the old one.
 	 */
 	if (list_length(ec->ec_members) == 2 &&
-		list_length(ec->ec_sources) == 1)
+		bms_get_singleton_member(ec->ec_source_indexes, &i))
 	{
-		RestrictInfo *restrictinfo = (RestrictInfo *) linitial(ec->ec_sources);
+		RestrictInfo *restrictinfo = list_nth_node(RestrictInfo, root->eq_sources, i);
 
 		distribute_restrictinfo_to_rels(root, restrictinfo);
 		return;
@@ -1141,9 +1266,11 @@ generate_base_implied_equalities_const(PlannerInfo *root,
 	 * machinery might be able to exclude relations on the basis of generated
 	 * "var = const" equalities, but "var = param" won't work for that.
 	 */
-	foreach(lc, ec->ec_members)
+	i = -1;
+	while ((i = bms_next_member(ec->ec_norel_indexes, i)) >= 0)
 	{
-		EquivalenceMember *cur_em = (EquivalenceMember *) lfirst(lc);
+		EquivalenceMember *cur_em = list_nth_node(EquivalenceMember,
+												  root->eq_members, i);
 
 		if (cur_em->em_is_const)
 		{
@@ -1187,9 +1314,9 @@ generate_base_implied_equalities_const(PlannerInfo *root,
 
 		/*
 		 * If the clause didn't degenerate to a constant, fill in the correct
-		 * markings for a mergejoinable clause, and save it in ec_derives. (We
+		 * markings for a mergejoinable clause, and save it in eq_derives. (We
 		 * will not re-use such clauses directly, but selectivity estimation
-		 * may consult the list later.  Note that this use of ec_derives does
+		 * may consult the list later.  Note that this use of eq_derives does
 		 * not overlap with its use for join clauses, since we never generate
 		 * join clauses from an ec_has_const eclass.)
 		 */
@@ -1199,7 +1326,8 @@ generate_base_implied_equalities_const(PlannerInfo *root,
 			rinfo->left_ec = rinfo->right_ec = ec;
 			rinfo->left_em = cur_em;
 			rinfo->right_em = const_em;
-			ec->ec_derives = lappend(ec->ec_derives, rinfo);
+
+			add_eq_derive(root, ec, rinfo);
 		}
 	}
 }
@@ -1212,7 +1340,8 @@ generate_base_implied_equalities_no_const(PlannerInfo *root,
 										  EquivalenceClass *ec)
 {
 	EquivalenceMember **prev_ems;
-	ListCell   *lc;
+	Bitmapset  *matching_ems;
+	int			i;
 
 	/*
 	 * We scan the EC members once and track the last-seen member for each
@@ -1225,9 +1354,12 @@ generate_base_implied_equalities_no_const(PlannerInfo *root,
 	prev_ems = (EquivalenceMember **)
 		palloc0(root->simple_rel_array_size * sizeof(EquivalenceMember *));
 
-	foreach(lc, ec->ec_members)
+	matching_ems = bms_difference(ec->ec_member_indexes, ec->ec_norel_indexes);
+	i = -1;
+	while ((i = bms_next_member(matching_ems, i)) >= 0)
 	{
-		EquivalenceMember *cur_em = (EquivalenceMember *) lfirst(lc);
+		EquivalenceMember *cur_em = list_nth_node(EquivalenceMember,
+												  root->eq_members, i);
 		int			relid;
 
 		Assert(!cur_em->em_is_child);	/* no children yet */
@@ -1265,7 +1397,7 @@ generate_base_implied_equalities_no_const(PlannerInfo *root,
 			/*
 			 * If the clause didn't degenerate to a constant, fill in the
 			 * correct markings for a mergejoinable clause.  We don't put it
-			 * in ec_derives however; we don't currently need to re-find such
+			 * in eq_derives however; we don't currently need to re-find such
 			 * clauses, and we don't want to clutter that list with non-join
 			 * clauses.
 			 */
@@ -1289,11 +1421,15 @@ generate_base_implied_equalities_no_const(PlannerInfo *root,
 	 * for this eclass.  Perhaps this could be improved by doing some
 	 * pre-analysis of which members we prefer to join, but it's no worse than
 	 * what happened in the pre-8.3 code.  (Note: rebuild_eclass_attr_needed
-	 * needs to match this code.)
+	 * needs to match this code.)  We're able to make use of
+	 * matching_ems from above.  We're not going to find Vars in
+	 * em_const_indexes.
 	 */
-	foreach(lc, ec->ec_members)
+	i = -1;
+	while ((i = bms_next_member(matching_ems, i)) >= 0)
 	{
-		EquivalenceMember *cur_em = (EquivalenceMember *) lfirst(lc);
+		EquivalenceMember *cur_em = list_nth_node(EquivalenceMember,
+												  root->eq_members, i);
 		List	   *vars = pull_var_clause((Node *) cur_em->em_expr,
 										   PVC_RECURSE_AGGREGATES |
 										   PVC_RECURSE_WINDOWFUNCS |
@@ -1302,6 +1438,7 @@ generate_base_implied_equalities_no_const(PlannerInfo *root,
 		add_vars_to_targetlist(root, vars, ec->ec_relids);
 		list_free(vars);
 	}
+	bms_free(matching_ems);
 }
 
 /*
@@ -1322,11 +1459,12 @@ static void
 generate_base_implied_equalities_broken(PlannerInfo *root,
 										EquivalenceClass *ec)
 {
-	ListCell   *lc;
+	int			i = -1;
 
-	foreach(lc, ec->ec_sources)
+	while ((i = bms_next_member(ec->ec_source_indexes, i)) >= 0)
 	{
-		RestrictInfo *restrictinfo = (RestrictInfo *) lfirst(lc);
+		RestrictInfo *restrictinfo = list_nth_node(RestrictInfo,
+												   root->eq_sources, i);
 
 		if (ec->ec_has_const ||
 			bms_membership(restrictinfo->required_relids) != BMS_MULTIPLE)
@@ -1367,11 +1505,11 @@ generate_base_implied_equalities_broken(PlannerInfo *root,
  * Because the same join clauses are likely to be needed multiple times as
  * we consider different join paths, we avoid generating multiple copies:
  * whenever we select a particular pair of EquivalenceMembers to join,
- * we check to see if the pair matches any original clause (in ec_sources)
- * or previously-built clause (in ec_derives).  This saves memory and allows
- * re-use of information cached in RestrictInfos.  We also avoid generating
- * commutative duplicates, i.e. if the algorithm selects "a.x = b.y" but
- * we already have "b.y = a.x", we return the existing clause.
+ * we check to see if the pair matches any original clause in root's
+ * eq_sources or previously-built clause (in root's eq_derives).  This saves
+ * memory and allows re-use of information cached in RestrictInfos.  We also
+ * avoid generating commutative duplicates, i.e. if the algorithm selects
+ * "a.x = b.y" but we already have "b.y = a.x", we return the existing clause.
  *
  * If we are considering an outer join, sjinfo is the associated OJ info,
  * otherwise it can be NULL.
@@ -1559,6 +1697,8 @@ generate_join_implied_equalities_normal(PlannerInfo *root,
 										Relids outer_relids,
 										Relids inner_relids)
 {
+	EquivalenceMemberIterator iter;
+	EquivalenceMember *cur_em;
 	List	   *result = NIL;
 	List	   *new_members = NIL;
 	List	   *outer_members = NIL;
@@ -1574,10 +1714,10 @@ generate_join_implied_equalities_normal(PlannerInfo *root,
 	 * as well as to at least one input member, plus enforce at least one
 	 * outer-rel member equal to at least one inner-rel member.
 	 */
-	foreach(lc1, ec->ec_members)
-	{
-		EquivalenceMember *cur_em = (EquivalenceMember *) lfirst(lc1);
+	setup_eclass_member_iterator(&iter, root, ec, join_relids, true, false);
 
+	while ((cur_em = eclass_member_iterator_next(&iter)) != NULL)
+	{
 		/*
 		 * We don't need to check explicitly for child EC members.  This test
 		 * against join_relids will cause them to be ignored except when
@@ -1594,6 +1734,8 @@ generate_join_implied_equalities_normal(PlannerInfo *root,
 			new_members = lappend(new_members, cur_em);
 	}
 
+	eclass_member_iterator_dispose(&iter);
+
 	/*
 	 * First, select the joinclause if needed.  We can equate any one outer
 	 * member to any one inner member, but we have to find a datatype
@@ -1691,7 +1833,7 @@ generate_join_implied_equalities_normal(PlannerInfo *root,
 
 		foreach(lc1, new_members)
 		{
-			EquivalenceMember *cur_em = (EquivalenceMember *) lfirst(lc1);
+			cur_em = (EquivalenceMember *) lfirst(lc1);
 
 			if (prev_em != NULL)
 			{
@@ -1736,12 +1878,16 @@ generate_join_implied_equalities_broken(PlannerInfo *root,
 										Relids nominal_inner_relids,
 										RelOptInfo *inner_rel)
 {
+	Bitmapset  *matching_es;
 	List	   *result = NIL;
-	ListCell   *lc;
+	int			i;
 
-	foreach(lc, ec->ec_sources)
+	matching_es = get_ec_source_indexes(root, ec, nominal_join_relids);
+	i = -1;
+	while ((i = bms_next_member(matching_es, i)) >= 0)
 	{
-		RestrictInfo *restrictinfo = (RestrictInfo *) lfirst(lc);
+		RestrictInfo *restrictinfo = list_nth_node(RestrictInfo,
+												   root->eq_sources, i);
 		Relids		clause_relids = restrictinfo->required_relids;
 
 		if (bms_is_subset(clause_relids, nominal_join_relids) &&
@@ -1753,12 +1899,12 @@ generate_join_implied_equalities_broken(PlannerInfo *root,
 	/*
 	 * If we have to translate, just brute-force apply adjust_appendrel_attrs
 	 * to all the RestrictInfos at once.  This will result in returning
-	 * RestrictInfos that are not listed in ec_derives, but there shouldn't be
+	 * RestrictInfos that are not listed in eq_derives, but there shouldn't be
 	 * any duplication, and it's a sufficiently narrow corner case that we
 	 * shouldn't sweat too much over it anyway.
 	 *
 	 * Since inner_rel might be an indirect descendant of the baserel
-	 * mentioned in the ec_sources clauses, we have to be prepared to apply
+	 * mentioned in the eq_sources clauses, we have to be prepared to apply
 	 * multiple levels of Var translation.
 	 */
 	if (IS_OTHER_REL(inner_rel) && result != NIL)
@@ -1820,10 +1966,11 @@ create_join_clause(PlannerInfo *root,
 				   EquivalenceMember *rightem,
 				   EquivalenceClass *parent_ec)
 {
+	Bitmapset  *matches;
 	RestrictInfo *rinfo;
 	RestrictInfo *parent_rinfo = NULL;
-	ListCell   *lc;
 	MemoryContext oldcontext;
+	int			i;
 
 	/*
 	 * Search to see if we already built a RestrictInfo for this pair of
@@ -1834,9 +1981,12 @@ create_join_clause(PlannerInfo *root,
 	 * it's not identical, it'd better have the same effects, or the operator
 	 * families we're using are broken.
 	 */
-	foreach(lc, ec->ec_sources)
+	matches = bms_int_members(get_ec_source_indexes_strict(root, ec, leftem->em_relids),
+							  get_ec_source_indexes_strict(root, ec, rightem->em_relids));
+	i = -1;
+	while ((i = bms_next_member(matches, i)) >= 0)
 	{
-		rinfo = (RestrictInfo *) lfirst(lc);
+		rinfo = list_nth_node(RestrictInfo, root->eq_sources, i);
 		if (rinfo->left_em == leftem &&
 			rinfo->right_em == rightem &&
 			rinfo->parent_ec == parent_ec)
@@ -1847,9 +1997,13 @@ create_join_clause(PlannerInfo *root,
 			return rinfo;
 	}
 
-	foreach(lc, ec->ec_derives)
+	matches = bms_int_members(get_ec_derive_indexes_strict(root, ec, leftem->em_relids),
+							  get_ec_derive_indexes_strict(root, ec, rightem->em_relids));
+
+	i = -1;
+	while ((i = bms_next_member(matches, i)) >= 0)
 	{
-		rinfo = (RestrictInfo *) lfirst(lc);
+		rinfo = list_nth_node(RestrictInfo, root->eq_derives, i);
 		if (rinfo->left_em == leftem &&
 			rinfo->right_em == rightem &&
 			rinfo->parent_ec == parent_ec)
@@ -1922,7 +2076,7 @@ create_join_clause(PlannerInfo *root,
 	rinfo->left_em = leftem;
 	rinfo->right_em = rightem;
 	/* and save it for possible re-use */
-	ec->ec_derives = lappend(ec->ec_derives, rinfo);
+	add_eq_derive(root, ec, rinfo);
 
 	MemoryContextSwitchTo(oldcontext);
 
@@ -2132,7 +2286,8 @@ reconsider_outer_join_clause(PlannerInfo *root, OuterJoinClauseInfo *ojcinfo,
 				left_type,
 				right_type,
 				inner_datatype;
-	Relids		inner_relids;
+	Relids		outer_relids,
+				inner_relids;
 	ListCell   *lc1;
 
 	Assert(is_opclause(rinfo->clause));
@@ -2146,6 +2301,7 @@ reconsider_outer_join_clause(PlannerInfo *root, OuterJoinClauseInfo *ojcinfo,
 		outervar = (Expr *) get_leftop(rinfo->clause);
 		innervar = (Expr *) get_rightop(rinfo->clause);
 		inner_datatype = right_type;
+		outer_relids = rinfo->left_relids;
 		inner_relids = rinfo->right_relids;
 	}
 	else
@@ -2153,6 +2309,7 @@ reconsider_outer_join_clause(PlannerInfo *root, OuterJoinClauseInfo *ojcinfo,
 		outervar = (Expr *) get_rightop(rinfo->clause);
 		innervar = (Expr *) get_leftop(rinfo->clause);
 		inner_datatype = left_type;
+		outer_relids = rinfo->right_relids;
 		inner_relids = rinfo->left_relids;
 	}
 
@@ -2160,8 +2317,10 @@ reconsider_outer_join_clause(PlannerInfo *root, OuterJoinClauseInfo *ojcinfo,
 	foreach(lc1, root->eq_classes)
 	{
 		EquivalenceClass *cur_ec = (EquivalenceClass *) lfirst(lc1);
+		EquivalenceMemberIterator iter;
+		EquivalenceMember *cur_em;
 		bool		match;
-		ListCell   *lc2;
+		int			i;
 
 		/* Ignore EC unless it contains pseudoconstants */
 		if (!cur_ec->ec_has_const)
@@ -2176,10 +2335,12 @@ reconsider_outer_join_clause(PlannerInfo *root, OuterJoinClauseInfo *ojcinfo,
 			continue;
 		/* Does it contain a match to outervar? */
 		match = false;
-		foreach(lc2, cur_ec->ec_members)
-		{
-			EquivalenceMember *cur_em = (EquivalenceMember *) lfirst(lc2);
 
+		setup_eclass_member_strict_iterator(&iter, root, cur_ec, outer_relids,
+											false, true);
+
+		while ((cur_em = eclass_member_iterator_strict_next(&iter)) != NULL)
+		{
 			Assert(!cur_em->em_is_child);	/* no children yet */
 			if (equal(outervar, cur_em->em_expr))
 			{
@@ -2187,6 +2348,8 @@ reconsider_outer_join_clause(PlannerInfo *root, OuterJoinClauseInfo *ojcinfo,
 				break;
 			}
 		}
+		eclass_member_iterator_dispose(&iter);
+
 		if (!match)
 			continue;			/* no match, so ignore this EC */
 
@@ -2196,13 +2359,15 @@ reconsider_outer_join_clause(PlannerInfo *root, OuterJoinClauseInfo *ojcinfo,
 		 * constant before we can decide to throw away the outer-join clause.
 		 */
 		match = false;
-		foreach(lc2, cur_ec->ec_members)
+		i = -1;
+		while ((i = bms_next_member(cur_ec->ec_norel_indexes, i)) >= 0)
 		{
-			EquivalenceMember *cur_em = (EquivalenceMember *) lfirst(lc2);
 			Oid			eq_op;
 			RestrictInfo *newrinfo;
 			JoinDomain *jdomain;
 
+			cur_em = list_nth_node(EquivalenceMember, root->eq_members, i);
+
 			if (!cur_em->em_is_const)
 				continue;		/* ignore non-const members */
 			eq_op = select_equality_operator(cur_ec,
@@ -2272,11 +2437,12 @@ reconsider_full_join_clause(PlannerInfo *root, OuterJoinClauseInfo *ojcinfo)
 	{
 		EquivalenceClass *cur_ec = (EquivalenceClass *) lfirst(lc1);
 		EquivalenceMember *coal_em = NULL;
+		Bitmapset  *matching_ems;
 		bool		match;
 		bool		matchleft;
 		bool		matchright;
-		ListCell   *lc2;
 		int			coal_idx = -1;
+		int			i;
 
 		/* Ignore EC unless it contains pseudoconstants */
 		if (!cur_ec->ec_has_const)
@@ -2303,10 +2469,14 @@ reconsider_full_join_clause(PlannerInfo *root, OuterJoinClauseInfo *ojcinfo)
 		 * the two column types). Is it OK to strip implicit coercions from
 		 * the COALESCE arguments?
 		 */
+		matching_ems = get_ecmember_indexes_strict(root, cur_ec,
+												   rinfo->clause_relids, true,
+												   false);
 		match = false;
-		foreach(lc2, cur_ec->ec_members)
+		i = -1;
+		while ((i = bms_next_member(matching_ems, i)) >= 0)
 		{
-			coal_em = (EquivalenceMember *) lfirst(lc2);
+			coal_em = list_nth_node(EquivalenceMember, root->eq_members, i);
 			Assert(!coal_em->em_is_child);	/* no children yet */
 			if (IsA(coal_em->em_expr, CoalesceExpr))
 			{
@@ -2333,7 +2503,7 @@ reconsider_full_join_clause(PlannerInfo *root, OuterJoinClauseInfo *ojcinfo)
 
 				if (equal(leftvar, cfirst) && equal(rightvar, csecond))
 				{
-					coal_idx = foreach_current_index(lc2);
+					coal_idx = i;
 					match = true;
 					break;
 				}
@@ -2349,9 +2519,11 @@ reconsider_full_join_clause(PlannerInfo *root, OuterJoinClauseInfo *ojcinfo)
 		 * decide to throw away the outer-join clause.
 		 */
 		matchleft = matchright = false;
-		foreach(lc2, cur_ec->ec_members)
+		i = -1;
+		while ((i = bms_next_member(cur_ec->ec_norel_indexes, i)) >= 0)
 		{
-			EquivalenceMember *cur_em = (EquivalenceMember *) lfirst(lc2);
+			EquivalenceMember *cur_em = list_nth_node(EquivalenceMember,
+													  root->eq_members, i);
 			Oid			eq_op;
 			RestrictInfo *newrinfo;
 			JoinDomain *jdomain;
@@ -2399,11 +2571,28 @@ reconsider_full_join_clause(PlannerInfo *root, OuterJoinClauseInfo *ojcinfo)
 		 * we can throw away the full-join clause as redundant.  Moreover, we
 		 * can remove the COALESCE entry from the EC, since the added
 		 * restrictions ensure it will always have the expected value. (We
-		 * don't bother trying to update ec_relids or ec_sources.)
+		 * don't bother trying to update ec_relids or root's eq_sources.)
 		 */
 		if (matchleft && matchright)
 		{
-			cur_ec->ec_members = list_delete_nth_cell(cur_ec->ec_members, coal_idx);
+			/* XXX performance of list_delete()?? */
+			cur_ec->ec_members = list_delete(cur_ec->ec_members, coal_em);
+			cur_ec->ec_member_indexes = bms_del_member(cur_ec->ec_member_indexes,
+													   coal_idx);
+			cur_ec->ec_nonchild_indexes = bms_del_member(cur_ec->ec_nonchild_indexes,
+														 coal_idx);
+			/* no need to adjust ec_norel_indexes */
+
+			/* Remove the member from each of the relations */
+			i = -1;
+			while ((i = bms_next_member(coal_em->em_relids, i)) >= 0)
+			{
+				RangeTblEntry *rte = root->simple_rte_array[i];
+
+				rte->eclass_member_indexes =
+					bms_del_member(rte->eclass_member_indexes, coal_idx);
+			}
+
 			return true;
 		}
 
@@ -2498,13 +2687,16 @@ bool
 exprs_known_equal(PlannerInfo *root, Node *item1, Node *item2, Oid opfamily)
 {
 	ListCell   *lc1;
+	Relids		item1_relids = pull_varnos(root, item1);
+	Relids		item2_relids = pull_varnos(root, item2);
 
 	foreach(lc1, root->eq_classes)
 	{
 		EquivalenceClass *ec = (EquivalenceClass *) lfirst(lc1);
 		bool		item1member = false;
 		bool		item2member = false;
-		ListCell   *lc2;
+		Bitmapset  *matching_ems;
+		int			i;
 
 		/* Never match to a volatile EC */
 		if (ec->ec_has_volatile)
@@ -2521,9 +2713,13 @@ exprs_known_equal(PlannerInfo *root, Node *item1, Node *item2, Oid opfamily)
 			!list_member_oid(ec->ec_opfamilies, opfamily))
 			continue;
 
-		foreach(lc2, ec->ec_members)
+		matching_ems = bms_join(get_ecmember_indexes_strict(root, ec, item1_relids, false, true),
+								get_ecmember_indexes_strict(root, ec, item2_relids, false, true));
+		i = -1;
+		while ((i = bms_next_member(matching_ems, i)) >= 0)
 		{
-			EquivalenceMember *em = (EquivalenceMember *) lfirst(lc2);
+			EquivalenceMember *em = list_nth_node(EquivalenceMember,
+												  root->eq_members, i);
 
 			if (em->em_is_child)
 				continue;		/* ignore children here */
@@ -2585,16 +2781,21 @@ match_eclasses_to_foreign_key_col(PlannerInfo *root,
 															 i);
 		EquivalenceMember *item1_em = NULL;
 		EquivalenceMember *item2_em = NULL;
-		ListCell   *lc2;
+		Bitmapset  *matching_ems;
+		int			j;
 
 		/* Never match to a volatile EC */
 		if (ec->ec_has_volatile)
 			continue;
 		/* It's okay to consider "broken" ECs here, see exprs_known_equal */
+		matching_ems = bms_join(get_ecmember_indexes_strict(root, ec, rel1->relids, false, false),
+								get_ecmember_indexes_strict(root, ec, rel2->relids, false, false));
 
-		foreach(lc2, ec->ec_members)
+		j = -1;
+		while ((j = bms_next_member(matching_ems, j)) >= 0)
 		{
-			EquivalenceMember *em = (EquivalenceMember *) lfirst(lc2);
+			EquivalenceMember *em = list_nth_node(EquivalenceMember,
+												  root->eq_members, j);
 			Var		   *var;
 
 			if (em->em_is_child)
@@ -2647,16 +2848,19 @@ match_eclasses_to_foreign_key_col(PlannerInfo *root,
  * Returns NULL if no such clause can be found.
  */
 RestrictInfo *
-find_derived_clause_for_ec_member(EquivalenceClass *ec,
+find_derived_clause_for_ec_member(PlannerInfo *root, EquivalenceClass *ec,
 								  EquivalenceMember *em)
 {
-	ListCell   *lc;
+	int			i;
 
 	Assert(ec->ec_has_const);
 	Assert(!em->em_is_const);
-	foreach(lc, ec->ec_derives)
+
+	i = -1;
+	while ((i = bms_next_member(ec->ec_derive_indexes, i)) >= 0)
 	{
-		RestrictInfo *rinfo = (RestrictInfo *) lfirst(lc);
+		RestrictInfo *rinfo = list_nth_node(RestrictInfo, root->eq_derives,
+											i);
 
 		/*
 		 * generate_base_implied_equalities_const will have put non-const
@@ -2707,7 +2911,8 @@ add_child_rel_equivalences(PlannerInfo *root,
 	while ((i = bms_next_member(parent_rel->eclass_indexes, i)) >= 0)
 	{
 		EquivalenceClass *cur_ec = (EquivalenceClass *) list_nth(root->eq_classes, i);
-		int			num_members;
+		EquivalenceMemberIterator iter;
+		EquivalenceMember *cur_em;
 
 		/*
 		 * If this EC contains a volatile expression, then generating child
@@ -2721,29 +2926,15 @@ add_child_rel_equivalences(PlannerInfo *root,
 		Assert(bms_is_subset(top_parent_relids, cur_ec->ec_relids));
 
 		/*
-		 * We don't use foreach() here because there's no point in scanning
-		 * newly-added child members, so we can stop after the last
-		 * pre-existing EC member.
+		 * Looping using the EquivalenceMemberIterator means we only loop over
+		 * the members which existed when we set up the iterator, not newly
+		 * added ones.
 		 */
-		num_members = list_length(cur_ec->ec_members);
-		for (int pos = 0; pos < num_members; pos++)
-		{
-			EquivalenceMember *cur_em = (EquivalenceMember *) list_nth(cur_ec->ec_members, pos);
-
-			if (cur_em->em_is_const)
-				continue;		/* ignore consts here */
-
-			/*
-			 * We consider only original EC members here, not
-			 * already-transformed child members.  Otherwise, if some original
-			 * member expression references more than one appendrel, we'd get
-			 * an O(N^2) explosion of useless derived expressions for
-			 * combinations of children.  (But add_child_join_rel_equivalences
-			 * may add targeted combinations for partitionwise-join purposes.)
-			 */
-			if (cur_em->em_is_child)
-				continue;		/* ignore children here */
+		setup_eclass_member_iterator(&iter, root, cur_ec, top_parent_relids,
+									 false, false);
 
+		while ((cur_em = eclass_member_iterator_next(&iter)) != NULL)
+		{
 			/*
 			 * Consider only members that reference and can be computed at
 			 * child's topmost parent rel.  In particular we want to exclude
@@ -2752,13 +2943,16 @@ add_child_rel_equivalences(PlannerInfo *root,
 			 * simple Var; and in any case it wouldn't produce a member that
 			 * has any use in creating plans for the child rel.
 			 */
-			if (bms_is_subset(cur_em->em_relids, top_parent_relids) &&
-				!bms_is_empty(cur_em->em_relids))
+			if (bms_is_subset(cur_em->em_relids, top_parent_relids))
 			{
 				/* OK, generate transformed child version */
 				Expr	   *child_expr;
 				Relids		new_relids;
 
+				Assert(!cur_em->em_is_const);
+				Assert(!cur_em->em_is_child);
+				Assert(!bms_is_empty(cur_em->em_relids));
+
 				if (parent_rel->reloptkind == RELOPT_BASEREL)
 				{
 					/* Simple single-level transformation */
@@ -2787,7 +2981,7 @@ add_child_rel_equivalences(PlannerInfo *root,
 											top_parent_relids);
 				new_relids = bms_add_members(new_relids, child_relids);
 
-				(void) add_eq_member(cur_ec, child_expr, new_relids,
+				(void) add_eq_member(root, cur_ec, child_expr, new_relids,
 									 cur_em->em_jdomain,
 									 cur_em, cur_em->em_datatype);
 
@@ -2795,6 +2989,7 @@ add_child_rel_equivalences(PlannerInfo *root,
 				child_rel->eclass_indexes = bms_add_member(child_rel->eclass_indexes, i);
 			}
 		}
+		eclass_member_iterator_dispose(&iter);
 	}
 }
 
@@ -2839,7 +3034,8 @@ add_child_join_rel_equivalences(PlannerInfo *root,
 	while ((i = bms_next_member(matching_ecs, i)) >= 0)
 	{
 		EquivalenceClass *cur_ec = (EquivalenceClass *) list_nth(root->eq_classes, i);
-		int			num_members;
+		EquivalenceMemberIterator iter;
+		EquivalenceMember *cur_em;
 
 		/*
 		 * If this EC contains a volatile expression, then generating child
@@ -2853,24 +3049,21 @@ add_child_join_rel_equivalences(PlannerInfo *root,
 		Assert(bms_overlap(top_parent_relids, cur_ec->ec_relids));
 
 		/*
-		 * We don't use foreach() here because there's no point in scanning
-		 * newly-added child members, so we can stop after the last
-		 * pre-existing EC member.
+		 * Looping using the EquivalenceMemberIterator means we only loop over
+		 * the members which existed when we set up the iterator, not newly
+		 * added ones.
 		 */
-		num_members = list_length(cur_ec->ec_members);
-		for (int pos = 0; pos < num_members; pos++)
+		setup_eclass_member_iterator(&iter, root, cur_ec, top_parent_relids,
+									 false, false);
+
+		while ((cur_em = eclass_member_iterator_next(&iter)) != NULL)
 		{
-			EquivalenceMember *cur_em = (EquivalenceMember *) list_nth(cur_ec->ec_members, pos);
+			Expr	   *child_expr;
+			Relids		new_relids;
 
-			if (cur_em->em_is_const)
-				continue;		/* ignore consts here */
-
-			/*
-			 * We consider only original EC members here, not
-			 * already-transformed child members.
-			 */
-			if (cur_em->em_is_child)
-				continue;		/* ignore children here */
+			Assert(!cur_em->em_is_const);
+			Assert(!cur_em->em_is_child);
+			Assert(bms_overlap(cur_em->em_relids, top_parent_relids));
 
 			/*
 			 * We may ignore expressions that reference a single baserel,
@@ -2879,47 +3072,40 @@ add_child_join_rel_equivalences(PlannerInfo *root,
 			if (bms_membership(cur_em->em_relids) != BMS_MULTIPLE)
 				continue;
 
-			/* Does this member reference child's topmost parent rel? */
-			if (bms_overlap(cur_em->em_relids, top_parent_relids))
+			if (parent_joinrel->reloptkind == RELOPT_JOINREL)
 			{
-				/* Yes, generate transformed child version */
-				Expr	   *child_expr;
-				Relids		new_relids;
-
-				if (parent_joinrel->reloptkind == RELOPT_JOINREL)
-				{
-					/* Simple single-level transformation */
-					child_expr = (Expr *)
-						adjust_appendrel_attrs(root,
-											   (Node *) cur_em->em_expr,
-											   nappinfos, appinfos);
-				}
-				else
-				{
-					/* Must do multi-level transformation */
-					Assert(parent_joinrel->reloptkind == RELOPT_OTHER_JOINREL);
-					child_expr = (Expr *)
-						adjust_appendrel_attrs_multilevel(root,
-														  (Node *) cur_em->em_expr,
-														  child_joinrel,
-														  child_joinrel->top_parent);
-				}
+				/* Simple single-level transformation */
+				child_expr = (Expr *)
+					adjust_appendrel_attrs(root,
+										   (Node *) cur_em->em_expr,
+										   nappinfos, appinfos);
+			}
+			else
+			{
+				/* Must do multi-level transformation */
+				Assert(parent_joinrel->reloptkind == RELOPT_OTHER_JOINREL);
+				child_expr = (Expr *)
+					adjust_appendrel_attrs_multilevel(root,
+													  (Node *) cur_em->em_expr,
+													  child_joinrel,
+													  child_joinrel->top_parent);
+			}
 
-				/*
-				 * Transform em_relids to match.  Note we do *not* do
-				 * pull_varnos(child_expr) here, as for example the
-				 * transformation might have substituted a constant, but we
-				 * don't want the child member to be marked as constant.
-				 */
-				new_relids = bms_difference(cur_em->em_relids,
-											top_parent_relids);
-				new_relids = bms_add_members(new_relids, child_relids);
+			/*
+			 * Transform em_relids to match.  Note we do *not* do
+			 * pull_varnos(child_expr) here, as for example the
+			 * transformation might have substituted a constant, but we
+			 * don't want the child member to be marked as constant.
+			 */
+			new_relids = bms_difference(cur_em->em_relids,
+										top_parent_relids);
+			new_relids = bms_add_members(new_relids, child_relids);
 
-				(void) add_eq_member(cur_ec, child_expr, new_relids,
-									 cur_em->em_jdomain,
-									 cur_em, cur_em->em_datatype);
-			}
+			(void) add_eq_member(root, cur_ec, child_expr, new_relids,
+								 cur_em->em_jdomain,
+								 cur_em, cur_em->em_datatype);
 		}
+		eclass_member_iterator_dispose(&iter);
 	}
 
 	MemoryContextSwitchTo(oldcontext);
@@ -2966,7 +3152,8 @@ add_setop_child_rel_equivalences(PlannerInfo *root, RelOptInfo *child_rel,
 		 * likewise, the JoinDomain can be that of the initial member of the
 		 * Pathkey's EquivalenceClass.
 		 */
-		add_eq_member(pk->pk_eclass,
+		add_eq_member(root,
+					  pk->pk_eclass,
 					  tle->expr,
 					  child_rel->relids,
 					  parent_em->em_jdomain,
@@ -3039,7 +3226,8 @@ generate_implied_equalities_for_column(PlannerInfo *root,
 	{
 		EquivalenceClass *cur_ec = (EquivalenceClass *) list_nth(root->eq_classes, i);
 		EquivalenceMember *cur_em;
-		ListCell   *lc2;
+		EquivalenceMemberIterator iter;
+		int			j;
 
 		/* Sanity check eclass_indexes only contain ECs for rel */
 		Assert(is_child_rel || bms_is_subset(rel->relids, cur_ec->ec_relids));
@@ -3061,16 +3249,19 @@ generate_implied_equalities_for_column(PlannerInfo *root,
 		 * corner cases, so for now we live with just reporting the first
 		 * match.  See also get_eclass_for_sort_expr.)
 		 */
-		cur_em = NULL;
-		foreach(lc2, cur_ec->ec_members)
+		setup_eclass_member_iterator(&iter, root, cur_ec, rel->relids, true,
+									 false);
+
+		while ((cur_em = eclass_member_iterator_next(&iter)) != NULL)
 		{
-			cur_em = (EquivalenceMember *) lfirst(lc2);
 			if (bms_equal(cur_em->em_relids, rel->relids) &&
 				callback(root, rel, cur_ec, cur_em, callback_arg))
 				break;
 			cur_em = NULL;
 		}
 
+		eclass_member_iterator_dispose(&iter);
+
 		if (!cur_em)
 			continue;
 
@@ -3078,14 +3269,15 @@ generate_implied_equalities_for_column(PlannerInfo *root,
 		 * Found our match.  Scan the other EC members and attempt to generate
 		 * joinclauses.
 		 */
-		foreach(lc2, cur_ec->ec_members)
+		j = -1;
+		while ((j = bms_next_member(cur_ec->ec_nonchild_indexes, j)) >= 0)
 		{
-			EquivalenceMember *other_em = (EquivalenceMember *) lfirst(lc2);
+			EquivalenceMember *other_em = list_nth_node(EquivalenceMember,
+														root->eq_members, j);
 			Oid			eq_op;
 			RestrictInfo *rinfo;
 
-			if (other_em->em_is_child)
-				continue;		/* ignore children here */
+			Assert(!other_em->em_is_child);
 
 			/* Make sure it'll be a join to a different rel */
 			if (other_em == cur_em ||
@@ -3193,7 +3385,7 @@ have_relevant_eclass_joinclause(PlannerInfo *root,
 		 * surely be true if both of them overlap ec_relids.)
 		 *
 		 * Note we don't test ec_broken; if we did, we'd need a separate code
-		 * path to look through ec_sources.  Checking the membership anyway is
+		 * path to look through eq_sources.  Checking the membership anyway is
 		 * OK as a possibly-overoptimistic heuristic.
 		 *
 		 * We don't test ec_has_const either, even though a const eclass won't
@@ -3268,7 +3460,7 @@ eclass_useful_for_merging(PlannerInfo *root,
 						  RelOptInfo *rel)
 {
 	Relids		relids;
-	ListCell   *lc;
+	int			i;
 
 	Assert(!eclass->ec_merged);
 
@@ -3281,7 +3473,7 @@ eclass_useful_for_merging(PlannerInfo *root,
 
 	/*
 	 * Note we don't test ec_broken; if we did, we'd need a separate code path
-	 * to look through ec_sources.  Checking the members anyway is OK as a
+	 * to look through eq_sources.  Checking the members anyway is OK as a
 	 * possibly-overoptimistic heuristic.
 	 */
 
@@ -3299,12 +3491,14 @@ eclass_useful_for_merging(PlannerInfo *root,
 		return false;
 
 	/* To join, we need a member not in the given rel */
-	foreach(lc, eclass->ec_members)
+	i = -1;
+	while ((i = bms_next_member(eclass->ec_nonchild_indexes, i)) >= 0)
 	{
-		EquivalenceMember *cur_em = (EquivalenceMember *) lfirst(lc);
+		EquivalenceMember *cur_em =
+		list_nth_node(EquivalenceMember, root->eq_members, i);
 
-		if (cur_em->em_is_child)
-			continue;			/* ignore children here */
+		/* we don't expect child members here */
+		Assert(!cur_em->em_is_child);
 
 		if (!bms_overlap(cur_em->em_relids, relids))
 			return true;
@@ -3392,7 +3586,7 @@ get_eclass_indexes_for_relids(PlannerInfo *root, Relids relids)
 	/* Should be OK to rely on eclass_indexes */
 	Assert(root->ec_merging_done);
 
-	while ((i = bms_next_member(relids, i)) > 0)
+	while ((i = bms_next_member(relids, i)) >= 0)
 	{
 		RelOptInfo *rel = root->simple_rel_array[i];
 
@@ -3438,3 +3632,595 @@ get_common_eclass_indexes(PlannerInfo *root, Relids relids1, Relids relids2)
 	/* Calculate and return the common EC indexes, recycling the left input. */
 	return bms_int_members(rel1ecs, rel2ecs);
 }
+
+/*
+ * get_ecmember_indexes
+ *		Returns a Bitmapset with indexes into root->eq_members for all
+ *		EquivalenceMembers in 'ec' that have
+ *		bms_overlap(em->em_relids, relids) as true.  The returned indexes
+ *		may reference EquivalenceMembers with em_relids containing members
+ *		not mentioned in 'relids'.
+ *
+ * Returns a newly allocated Bitmapset which the caller is free to modify.
+ */
+Bitmapset *
+get_ecmember_indexes(PlannerInfo *root, EquivalenceClass *ec, Relids relids,
+					 bool with_children, bool with_norel_members)
+{
+	Bitmapset  *matching_ems;
+	Bitmapset  *rel_ems = NULL;
+	int			i = -1;
+
+	while ((i = bms_next_member(relids, i)) >= 0)
+	{
+		RangeTblEntry *rte = root->simple_rte_array[i];
+
+		rel_ems = bms_add_members(rel_ems, rte->eclass_member_indexes);
+	}
+
+#ifdef USE_ASSERT_CHECKING
+	/* verify the results look sane */
+	i = -1;
+	while ((i = bms_next_member(rel_ems, i)) >= 0)
+	{
+		EquivalenceMember *em = list_nth_node(EquivalenceMember,
+											  root->eq_members, i);
+
+		Assert(bms_overlap(em->em_relids, relids));
+	}
+#endif
+
+	/* remove EC members not mentioning the required rels. */
+	if (!with_children)
+		matching_ems = bms_int_members(rel_ems, ec->ec_nonchild_indexes);
+	else
+		matching_ems = bms_int_members(rel_ems, ec->ec_member_indexes);
+
+	/* now add any members with that are not mentioned by any relation */
+	if (with_norel_members)
+		matching_ems = bms_add_members(matching_ems, ec->ec_norel_indexes);
+
+	return matching_ems;
+}
+
+/*
+ * get_ecmember_indexes_strict
+ *		Returns a Bitmapset with indexes into root->eq_members for all
+ *		EquivalenceMembers in 'ec' that have
+ *		bms_is_subset(relids, em->em_relids) as true.
+ *
+ * Returns a newly allocated Bitmapset which the caller is free to modify.
+ */
+Bitmapset *
+get_ecmember_indexes_strict(PlannerInfo *root, EquivalenceClass *ec,
+							Relids relids, bool with_children,
+							bool with_norel_members)
+{
+	Bitmapset  *matching_ems = NULL;
+	int			i = bms_next_member(relids, -1);
+
+	if (i >= 0)
+	{
+		RangeTblEntry *rte = root->simple_rte_array[i];
+
+		/*
+		 * bms_intersect to the first relation to try to keep the resulting
+		 * Bitmapset as small as possible.  This saves having to make a
+		 * complete bms_copy() of one of them.  One may contain significantly
+		 * more words than the other.
+		 */
+		if (!with_children)
+			matching_ems = bms_intersect(rte->eclass_member_indexes,
+										 ec->ec_nonchild_indexes);
+		else
+			matching_ems = bms_intersect(rte->eclass_member_indexes,
+										 ec->ec_member_indexes);
+
+		while ((i = bms_next_member(relids, i)) >= 0)
+		{
+			rte = root->simple_rte_array[i];
+			matching_ems = bms_int_members(matching_ems,
+										   rte->eclass_member_indexes);
+		}
+	}
+
+#ifdef USE_ASSERT_CHECKING
+	/* verify the results look sane */
+	i = -1;
+	while ((i = bms_next_member(matching_ems, i)) >= 0)
+	{
+		EquivalenceMember *em = list_nth_node(EquivalenceMember,
+											  root->eq_members, i);
+
+		Assert(bms_is_subset(relids, em->em_relids));
+	}
+#endif
+
+	/* optionally add members with that are not mentioned by any relation */
+	if (with_norel_members)
+		matching_ems = bms_add_members(matching_ems, ec->ec_norel_indexes);
+
+	return matching_ems;
+}
+
+/*
+ * The threshold for the number of members that must be in an EquivalenceClass
+ * before we switch to searching for EquivalenceMember by using the Bitmapset
+ * indexes stored in EquivalenceClass and RelOptInfo.  We don't want to make
+ * this too low as the manipulation of Bitmapsets slows this down for
+ * EquivalenceClasses with just a few members.  The linear search becomes very
+ * slow when an EquivalenceClass has a large number of members, as can happen
+ * when planning queries to partitioned tables.
+ */
+#define ECMEMBER_INDEX_THRESHOLD 16
+
+/*
+ * setup_eclass_member_iterator
+ *		Setup 'iter' so it's ready for eclass_member_iterator_next to start
+ *		searching for EquivalenceMembers matching the specified parameters.
+ *
+ * Once used, the iterator must be disposed of using
+ * eclass_member_iterator_dispose.
+ */
+void
+setup_eclass_member_iterator(EquivalenceMemberIterator *iter,
+							 PlannerInfo *root, EquivalenceClass *ec,
+							 Relids relids, bool with_children,
+							 bool with_norel_members)
+{
+	iter->orig_length = list_length(ec->ec_members);
+	iter->use_index = iter->orig_length >= ECMEMBER_INDEX_THRESHOLD;
+	iter->with_children = with_children;
+	iter->with_norel_members = with_norel_members;
+	iter->relids_empty = bms_is_empty(relids);
+#ifdef USE_ASSERT_CHECKING
+	iter->isstrict = false;
+#endif
+	iter->with_relids = relids;
+	iter->root = root;
+	iter->eclass = ec;
+
+#ifdef USE_ASSERT_CHECKING
+	if (1)
+#else
+	if (iter->use_index)
+#endif
+		iter->matching_ems = get_ecmember_indexes(root, ec, relids,
+												  with_children,
+												  with_norel_members);
+	else
+		iter->matching_ems = NULL;
+
+	iter->current_index = -1;
+
+#ifdef USE_ASSERT_CHECKING
+
+	/*
+	 * Verify that an iterator that uses the index and one that does not both
+	 * return the same EquivalenceMembers
+	 */
+	{
+		EquivalenceMemberIterator idx_iter;
+		EquivalenceMemberIterator noidx_iter;
+		EquivalenceMember *em;
+		List	   *list1 = NIL;
+		List	   *list2 = NIL;
+		ListCell   *lc1,
+				   *lc2;
+
+		memcpy(&idx_iter, iter, sizeof(EquivalenceMemberIterator));
+		memcpy(&noidx_iter, iter, sizeof(EquivalenceMemberIterator));
+
+		idx_iter.use_index = true;
+		noidx_iter.use_index = false;
+
+		while ((em = eclass_member_iterator_next(&idx_iter)) != NULL)
+			list1 = lappend(list1, em);
+
+		while ((em = eclass_member_iterator_next(&noidx_iter)) != NULL)
+			list2 = lappend(list2, em);
+
+		list_sort(list1, list_ptr_cmp);
+		list_sort(list2, list_ptr_cmp);
+
+		Assert(list_length(list1) == list_length(list2));
+
+		forboth(lc1, list1, lc2, list2)
+			Assert(lfirst(lc1) == lfirst(lc2));
+	}
+#endif
+
+}
+
+/*
+ * setup_eclass_member_strict_iterator
+ *		Setup 'iter' so it's ready for eclass_member_iterator_strict_next to
+ *		start searching for EquivalenceMembers matching the specified
+ *		parameters.
+ *
+ * Once used, the iterator must be disposed of using
+ * eclass_member_iterator_dispose.
+ */
+void
+setup_eclass_member_strict_iterator(EquivalenceMemberIterator *iter,
+									PlannerInfo *root, EquivalenceClass *ec,
+									Relids relids, bool with_children,
+									bool with_norel_members)
+{
+	iter->orig_length = list_length(ec->ec_members);
+	iter->use_index = iter->orig_length >= ECMEMBER_INDEX_THRESHOLD;
+	iter->with_children = with_children;
+	iter->with_norel_members = with_norel_members;
+	iter->relids_empty = bms_is_empty(relids);
+#ifdef USE_ASSERT_CHECKING
+	iter->isstrict = true;
+#endif
+	iter->with_relids = relids;
+	iter->root = root;
+	iter->eclass = ec;
+
+#ifdef USE_ASSERT_CHECKING
+	if (1)
+#else
+	if (iter->use_index)
+#endif
+		iter->matching_ems = get_ecmember_indexes_strict(root, ec, relids,
+														 with_children,
+														 with_norel_members);
+	else
+		iter->matching_ems = NULL;
+
+	iter->current_index = -1;
+
+#ifdef USE_ASSERT_CHECKING
+
+	/*
+	 * Verify that an iterator that uses the index and one that does not both
+	 * return the same EquivalenceMembers
+	 */
+	{
+		EquivalenceMemberIterator idx_iter;
+		EquivalenceMemberIterator noidx_iter;
+		EquivalenceMember *em;
+		List	   *list1 = NIL;
+		List	   *list2 = NIL;
+		ListCell   *lc1,
+				   *lc2;
+
+		memcpy(&idx_iter, iter, sizeof(EquivalenceMemberIterator));
+		memcpy(&noidx_iter, iter, sizeof(EquivalenceMemberIterator));
+
+		idx_iter.use_index = true;
+		noidx_iter.use_index = false;
+
+		while ((em = eclass_member_iterator_strict_next(&idx_iter)) != NULL)
+			list1 = lappend(list1, em);
+
+		while ((em = eclass_member_iterator_strict_next(&noidx_iter)) != NULL)
+			list2 = lappend(list2, em);
+
+		list_sort(list1, list_ptr_cmp);
+		list_sort(list2, list_ptr_cmp);
+
+		Assert(list_length(list1) == list_length(list2));
+
+		forboth(lc1, list1, lc2, list2)
+			Assert(lfirst(lc1) == lfirst(lc2));
+	}
+#endif
+}
+
+/*
+ * eclass_member_iterator_next
+ *		Fetch the next EquivalenceMember from an EquivalenceMemberIterator
+ *		which was set up by setup_eclass_member_iterator().  Returns NULL when
+ *		there are no more matching EquivalenceMembers.
+ */
+EquivalenceMember *
+eclass_member_iterator_next(EquivalenceMemberIterator *iter)
+{
+	/* Fail if this was used instead of eclass_member_iterator_strict_next */
+	Assert(!iter->isstrict);
+
+	if (iter->use_index)
+	{
+		iter->current_index = bms_next_member(iter->matching_ems,
+											  iter->current_index);
+		if (iter->current_index >= 0)
+			return list_nth_node(EquivalenceMember, iter->root->eq_members,
+								 iter->current_index);
+		return NULL;
+	}
+	else
+	{
+		ListCell   *lc;
+
+		for_each_from(lc, iter->eclass->ec_members, iter->current_index + 1)
+		{
+			EquivalenceMember *em = lfirst_node(EquivalenceMember, lc);
+
+			iter->current_index = foreach_current_index(lc);
+
+			/*
+			 * Some users of this iterator will be adding new
+			 * EquivalenceMember during the loop.  We must ensure we don't
+			 * return those, so here we return NULL when the loop index goes
+			 * beyond the original length of the ec_members list.
+			 */
+			if (iter->current_index >= iter->orig_length)
+				return NULL;
+
+			/* don't return child members when with_children==false */
+			if (!iter->with_children && em->em_is_child)
+				continue;
+
+			/*
+			 * When with_norel_members==true, make sure we return all members
+			 * without Vars.
+			 */
+			if (iter->with_norel_members && em->em_norel_expr)
+				return em;
+
+			/*
+			 * Don't return members which have no common rels with with_relids
+			 */
+			if (!bms_overlap(em->em_relids, iter->with_relids))
+				continue;
+
+			return em;
+		}
+		return NULL;
+	}
+}
+
+/*
+ * eclass_member_iterator_strict_next
+ *		Fetch the next EquivalenceMember from an EquivalenceMemberIterator
+ *		which was set up by setup_eclass_member_strict_iterator().  Returns
+ *		NULL when there are no more matching EquivalenceMembers.
+ */
+EquivalenceMember *
+eclass_member_iterator_strict_next(EquivalenceMemberIterator *iter)
+{
+	/* Fail if this was used instead of eclass_member_iterator_next */
+	Assert(iter->isstrict);
+
+	if (iter->use_index)
+	{
+		iter->current_index = bms_next_member(iter->matching_ems,
+											  iter->current_index);
+		if (iter->current_index >= 0)
+			return list_nth_node(EquivalenceMember, iter->root->eq_members,
+								 iter->current_index);
+		return NULL;
+	}
+	else
+	{
+		ListCell   *lc;
+
+		for_each_from(lc, iter->eclass->ec_members, iter->current_index + 1)
+		{
+			EquivalenceMember *em = lfirst_node(EquivalenceMember, lc);
+
+			iter->current_index = foreach_current_index(lc);
+
+			/*
+			 * Some users of this iterator will be adding new
+			 * EquivalenceMember during the loop.  We must ensure we don't
+			 * return those, so here we return NULL when the loop index goes
+			 * beyond the original length of the ec_members list.
+			 */
+			if (iter->current_index >= iter->orig_length)
+				return NULL;
+
+			/* don't return child members when with_children==false */
+			if (!iter->with_children && em->em_is_child)
+				continue;
+
+			/*
+			 * When with_norel_members==true, make sure we return all members
+			 * without Vars.
+			 */
+			if (iter->with_norel_members && em->em_norel_expr)
+				return em;
+
+			/*
+			 * Don't match members where em_relids that don't contain all rels
+			 * mentioned in with_relids.
+			 */
+			if (iter->relids_empty ||
+				!bms_is_subset(iter->with_relids, em->em_relids))
+				continue;
+
+			return em;
+		}
+		return NULL;
+	}
+}
+
+/*
+ * eclass_member_iterator_dispose
+ *		Free any memory allocated by the iterator
+ */
+void
+eclass_member_iterator_dispose(EquivalenceMemberIterator *iter)
+{
+	bms_free(iter->matching_ems);
+}
+
+
+/*
+ * get_ec_source_indexes
+ *		Returns a Bitmapset with indexes into root->eq_sources for all
+ *		RestrictInfos in 'ec' that have
+ *		bms_overlap(relids, rinfo->clause_relids) as true.
+ *
+ * Returns a newly allocated Bitmapset which the caller is free to modify.
+ */
+Bitmapset *
+get_ec_source_indexes(PlannerInfo *root, EquivalenceClass *ec, Relids relids)
+{
+	Bitmapset  *rel_esis = NULL;
+	int			i = -1;
+
+	while ((i = bms_next_member(relids, i)) >= 0)
+	{
+		RangeTblEntry *rte = root->simple_rte_array[i];
+
+		rel_esis = bms_add_members(rel_esis, rte->eclass_source_indexes);
+	}
+
+#ifdef USE_ASSERT_CHECKING
+	/* verify the results look sane */
+	i = -1;
+	while ((i = bms_next_member(rel_esis, i)) >= 0)
+	{
+		RestrictInfo *rinfo = list_nth_node(RestrictInfo, root->eq_sources,
+											i);
+
+		Assert(bms_overlap(relids, rinfo->clause_relids));
+	}
+#endif
+
+	/* bitwise-AND to leave only the ones for this EquivalenceClass */
+	return bms_int_members(rel_esis, ec->ec_source_indexes);
+}
+
+/*
+ * get_ec_source_indexes_strict
+ *		Returns a Bitmapset with indexes into root->eq_sources for all
+ *		RestrictInfos in 'ec' that have
+ *		bms_is_subset(relids, rinfo->clause_relids) as true.
+ *
+ * Returns a newly allocated Bitmapset which the caller is free to modify.
+ */
+Bitmapset *
+get_ec_source_indexes_strict(PlannerInfo *root, EquivalenceClass *ec,
+							 Relids relids)
+{
+	Bitmapset  *esis = NULL;
+	int			i = bms_next_member(relids, -1);
+
+	if (i >= 0)
+	{
+		RangeTblEntry *rte = root->simple_rte_array[i];
+
+		/*
+		 * bms_intersect to the first relation to try to keep the resulting
+		 * Bitmapset as small as possible.  This saves having to make a
+		 * complete bms_copy() of one of them.  One may contain significantly
+		 * more words than the other.
+		 */
+		esis = bms_intersect(ec->ec_source_indexes,
+							 rte->eclass_source_indexes);
+
+		while ((i = bms_next_member(relids, i)) >= 0)
+		{
+			rte = root->simple_rte_array[i];
+			esis = bms_int_members(esis, rte->eclass_source_indexes);
+		}
+	}
+
+#ifdef USE_ASSERT_CHECKING
+	/* verify the results look sane */
+	i = -1;
+	while ((i = bms_next_member(esis, i)) >= 0)
+	{
+		RestrictInfo *rinfo = list_nth_node(RestrictInfo, root->eq_sources,
+											i);
+
+		Assert(bms_is_subset(relids, rinfo->clause_relids));
+	}
+#endif
+
+	return esis;
+}
+
+/*
+ * get_ec_derive_indexes
+ *		Returns a Bitmapset with indexes into root->eq_derives for all
+ *		RestrictInfos in 'ec' that have
+ *		bms_overlap(relids, rinfo->clause_relids) as true.
+ *
+ * Returns a newly allocated Bitmapset which the caller is free to modify.
+ *
+ * XXX is this function even needed?
+ */
+Bitmapset *
+get_ec_derive_indexes(PlannerInfo *root, EquivalenceClass *ec, Relids relids)
+{
+	Bitmapset  *rel_edis = NULL;
+	int			i = -1;
+
+	while ((i = bms_next_member(relids, i)) >= 0)
+	{
+		RangeTblEntry *rte = root->simple_rte_array[i];
+
+		rel_edis = bms_add_members(rel_edis, rte->eclass_derive_indexes);
+	}
+
+#ifdef USE_ASSERT_CHECKING
+	/* verify the results look sane */
+	i = -1;
+	while ((i = bms_next_member(rel_edis, i)) >= 0)
+	{
+		RestrictInfo *rinfo = list_nth_node(RestrictInfo, root->eq_derives,
+											i);
+
+		Assert(bms_overlap(relids, rinfo->clause_relids));
+	}
+#endif
+
+	/* bitwise-AND to leave only the ones for this EquivalenceClass */
+	return bms_int_members(rel_edis, ec->ec_derive_indexes);
+}
+
+/*
+ * get_ec_derive_indexes_strict
+ *		Returns a Bitmapset with indexes into root->eq_derives for all
+ *		RestrictInfos in 'ec' that have
+ *		bms_is_subset(relids, rinfo->clause_relids) as true.
+ *
+ * Returns a newly allocated Bitmapset which the caller is free to modify.
+ */
+Bitmapset *
+get_ec_derive_indexes_strict(PlannerInfo *root, EquivalenceClass *ec,
+							 Relids relids)
+{
+	Bitmapset  *edis = NULL;
+	int			i = bms_next_member(relids, -1);
+
+	if (i >= 0)
+	{
+		RangeTblEntry *rte = root->simple_rte_array[i];
+
+		/*
+		 * bms_intersect to the first relation to try to keep the resulting
+		 * Bitmapset as small as possible.  This saves having to make a
+		 * complete bms_copy() of one of them.  One may contain significantly
+		 * more words than the other.
+		 */
+		edis = bms_intersect(ec->ec_derive_indexes,
+							 rte->eclass_derive_indexes);
+
+		while ((i = bms_next_member(relids, i)) >= 0)
+		{
+			rte = root->simple_rte_array[i];
+			edis = bms_int_members(edis, rte->eclass_derive_indexes);
+		}
+	}
+
+#ifdef USE_ASSERT_CHECKING
+	/* verify the results look sane */
+	i = -1;
+	while ((i = bms_next_member(edis, i)) >= 0)
+	{
+		RestrictInfo *rinfo = list_nth_node(RestrictInfo, root->eq_derives,
+											i);
+
+		Assert(bms_is_subset(relids, rinfo->clause_relids));
+	}
+#endif
+
+	return edis;
+}
diff --git a/src/backend/optimizer/path/indxpath.c b/src/backend/optimizer/path/indxpath.c
index 5f428e835b0..f658041f6b0 100644
--- a/src/backend/optimizer/path/indxpath.c
+++ b/src/backend/optimizer/path/indxpath.c
@@ -190,8 +190,8 @@ static IndexClause *expand_indexqual_rowcompare(PlannerInfo *root,
 												IndexOptInfo *index,
 												Oid expr_op,
 												bool var_on_left);
-static void match_pathkeys_to_index(IndexOptInfo *index, List *pathkeys,
-									List **orderby_clauses_p,
+static void match_pathkeys_to_index(PlannerInfo *root, IndexOptInfo *index,
+									List *pathkeys, List **orderby_clauses_p,
 									List **clause_columns_p);
 static Expr *match_clause_to_ordering_op(IndexOptInfo *index,
 										 int indexcol, Expr *clause, Oid pk_opfamily);
@@ -934,7 +934,7 @@ build_index_paths(PlannerInfo *root, RelOptInfo *rel,
 		 * query_pathkeys will allow an incremental sort to be considered on
 		 * the index's partially sorted results.
 		 */
-		match_pathkeys_to_index(index, root->query_pathkeys,
+		match_pathkeys_to_index(root, index, root->query_pathkeys,
 								&orderbyclauses,
 								&orderbyclausecols);
 		if (list_length(root->query_pathkeys) == list_length(orderbyclauses))
@@ -3726,8 +3726,8 @@ expand_indexqual_rowcompare(PlannerInfo *root,
  * item in the given 'pathkeys' list.
  */
 static void
-match_pathkeys_to_index(IndexOptInfo *index, List *pathkeys,
-						List **orderby_clauses_p,
+match_pathkeys_to_index(PlannerInfo *root, IndexOptInfo *index,
+						List *pathkeys, List **orderby_clauses_p,
 						List **clause_columns_p)
 {
 	ListCell   *lc1;
@@ -3742,8 +3742,9 @@ match_pathkeys_to_index(IndexOptInfo *index, List *pathkeys,
 	foreach(lc1, pathkeys)
 	{
 		PathKey    *pathkey = (PathKey *) lfirst(lc1);
+		Bitmapset  *matching_ems;
 		bool		found = false;
-		ListCell   *lc2;
+		int			i;
 
 
 		/* Pathkey must request default sort order for the target opfamily */
@@ -3763,9 +3764,16 @@ match_pathkeys_to_index(IndexOptInfo *index, List *pathkeys,
 		 * be considered to match more than one pathkey list, which is OK
 		 * here.  See also get_eclass_for_sort_expr.)
 		 */
-		foreach(lc2, pathkey->pk_eclass->ec_members)
+		matching_ems =
+			bms_intersect(pathkey->pk_eclass->ec_member_indexes,
+						  root->simple_rte_array[index->rel->relid]
+							  ->eclass_member_indexes);
+
+		i = -1;
+		while ((i = bms_next_member(matching_ems, i)) >= 0)
 		{
-			EquivalenceMember *member = (EquivalenceMember *) lfirst(lc2);
+			EquivalenceMember *member = list_nth_node(EquivalenceMember,
+													  root->eq_members, i);
 			int			indexcol;
 
 			/* No possibility of match if it references other relations */
diff --git a/src/backend/optimizer/path/pathkeys.c b/src/backend/optimizer/path/pathkeys.c
index 154eb505d75..59e3f8c136d 100644
--- a/src/backend/optimizer/path/pathkeys.c
+++ b/src/backend/optimizer/path/pathkeys.c
@@ -1141,18 +1141,19 @@ convert_subquery_pathkeys(PlannerInfo *root, RelOptInfo *rel,
 			 * outer query.
 			 */
 			int			best_score = -1;
-			ListCell   *j;
+			int			j = -1;
 
-			foreach(j, sub_eclass->ec_members)
+			while ((j = bms_next_member(sub_eclass->ec_nonchild_indexes, j)) >= 0)
 			{
-				EquivalenceMember *sub_member = (EquivalenceMember *) lfirst(j);
+				EquivalenceMember *sub_member = list_nth_node(EquivalenceMember,
+															  rel->subroot->eq_members,
+															  j);
 				Expr	   *sub_expr = sub_member->em_expr;
 				Oid			sub_expr_type = sub_member->em_datatype;
 				Oid			sub_expr_coll = sub_eclass->ec_collation;
 				ListCell   *k;
 
-				if (sub_member->em_is_child)
-					continue;	/* ignore children here */
+				Assert(!sub_member->em_is_child);
 
 				foreach(k, subquery_tlist)
 				{
@@ -1684,7 +1685,7 @@ select_outer_pathkeys_for_merge(PlannerInfo *root,
 		RestrictInfo *rinfo = (RestrictInfo *) lfirst(lc);
 		EquivalenceClass *oeclass;
 		int			score;
-		ListCell   *lc2;
+		int			i;
 
 		/* get the outer eclass */
 		update_mergeclause_eclasses(root, rinfo);
@@ -1705,13 +1706,16 @@ select_outer_pathkeys_for_merge(PlannerInfo *root,
 
 		/* compute score */
 		score = 0;
-		foreach(lc2, oeclass->ec_members)
+		i = -1;
+		while ((i = bms_next_member(oeclass->ec_nonchild_indexes, i)) >= 0)
 		{
-			EquivalenceMember *em = (EquivalenceMember *) lfirst(lc2);
+			EquivalenceMember *em = list_nth_node(EquivalenceMember,
+												  root->eq_members, i);
 
-			/* Potential future join partner? */
-			if (!em->em_is_const && !em->em_is_child &&
-				!bms_overlap(em->em_relids, joinrel->relids))
+			/* shouldn't be consts or child members in ec_nonchild_indexes */
+			Assert(!em->em_is_const && !em->em_is_child);
+
+			if (!bms_overlap(em->em_relids, joinrel->relids))
 				score++;
 		}
 
diff --git a/src/backend/optimizer/plan/analyzejoins.c b/src/backend/optimizer/plan/analyzejoins.c
index b33fc671775..fa5eb40d34d 100644
--- a/src/backend/optimizer/plan/analyzejoins.c
+++ b/src/backend/optimizer/plan/analyzejoins.c
@@ -38,7 +38,7 @@ static void remove_rel_from_query(PlannerInfo *root, int relid,
 								  SpecialJoinInfo *sjinfo);
 static void remove_rel_from_restrictinfo(RestrictInfo *rinfo,
 										 int relid, int ojrelid);
-static void remove_rel_from_eclass(EquivalenceClass *ec,
+static void remove_rel_from_eclass(PlannerInfo *root, EquivalenceClass *ec,
 								   int relid, int ojrelid);
 static List *remove_rel_from_joinlist(List *joinlist, int relid, int *nremoved);
 static bool rel_supports_distinctness(PlannerInfo *root, RelOptInfo *rel);
@@ -474,7 +474,7 @@ remove_rel_from_query(PlannerInfo *root, int relid, SpecialJoinInfo *sjinfo)
 
 		if (bms_is_member(relid, ec->ec_relids) ||
 			bms_is_member(ojrelid, ec->ec_relids))
-			remove_rel_from_eclass(ec, relid, ojrelid);
+			remove_rel_from_eclass(root, ec, relid, ojrelid);
 	}
 
 	/*
@@ -607,9 +607,11 @@ remove_rel_from_restrictinfo(RestrictInfo *rinfo, int relid, int ojrelid)
  * level(s).
  */
 static void
-remove_rel_from_eclass(EquivalenceClass *ec, int relid, int ojrelid)
+remove_rel_from_eclass(PlannerInfo *root, EquivalenceClass *ec, int relid,
+					   int ojrelid)
 {
 	ListCell   *lc;
+	int			i;
 
 	/* Fix up the EC's overall relids */
 	ec->ec_relids = bms_del_member(ec->ec_relids, relid);
@@ -627,18 +629,41 @@ remove_rel_from_eclass(EquivalenceClass *ec, int relid, int ojrelid)
 		if (bms_is_member(relid, cur_em->em_relids) ||
 			bms_is_member(ojrelid, cur_em->em_relids))
 		{
+			RangeTblEntry  *rte;
+
 			Assert(!cur_em->em_is_const);
+
+			/* Delete 'relid' from em_relids */
 			cur_em->em_relids = bms_del_member(cur_em->em_relids, relid);
+			rte = root->simple_rte_array[relid];
+			rte->eclass_member_indexes =
+				bms_del_member(rte->eclass_member_indexes, cur_em->em_index);
+
+			/* Delete 'ojrelid' from em_relids */
 			cur_em->em_relids = bms_del_member(cur_em->em_relids, ojrelid);
+			rte = root->simple_rte_array[ojrelid];
+			rte->eclass_member_indexes =
+				bms_del_member(rte->eclass_member_indexes, cur_em->em_index);
+
 			if (bms_is_empty(cur_em->em_relids))
+			{
+				/* Delete this EquivalenceMember with updating indexes */
 				ec->ec_members = foreach_delete_current(ec->ec_members, lc);
+				ec->ec_member_indexes =
+					bms_del_member(ec->ec_member_indexes, cur_em->em_index);
+				ec->ec_nonchild_indexes =
+					bms_del_member(ec->ec_nonchild_indexes, cur_em->em_index);
+				ec->ec_norel_indexes =
+					bms_del_member(ec->ec_norel_indexes, cur_em->em_index);
+			}
 		}
 	}
 
 	/* Fix up the source clauses, in case we can re-use them later */
-	foreach(lc, ec->ec_sources)
+	i = -1;
+	while ((i = bms_next_member(ec->ec_source_indexes, i)) >= 0)
 	{
-		RestrictInfo *rinfo = (RestrictInfo *) lfirst(lc);
+		RestrictInfo *rinfo = list_nth_node(RestrictInfo, root->eq_sources, i);
 
 		remove_rel_from_restrictinfo(rinfo, relid, ojrelid);
 	}
@@ -648,7 +673,7 @@ remove_rel_from_eclass(EquivalenceClass *ec, int relid, int ojrelid)
 	 * drop them.  (At this point, any such clauses would be base restriction
 	 * clauses, which we'd not need anymore anyway.)
 	 */
-	ec->ec_derives = NIL;
+	ec->ec_derive_indexes = NULL;
 }
 
 /*
diff --git a/src/backend/optimizer/plan/createplan.c b/src/backend/optimizer/plan/createplan.c
index 1caad5f3a61..2023f8d280e 100644
--- a/src/backend/optimizer/plan/createplan.c
+++ b/src/backend/optimizer/plan/createplan.c
@@ -264,8 +264,8 @@ static IncrementalSort *make_incrementalsort(Plan *lefttree,
 											 int numCols, int nPresortedCols,
 											 AttrNumber *sortColIdx, Oid *sortOperators,
 											 Oid *collations, bool *nullsFirst);
-static Plan *prepare_sort_from_pathkeys(Plan *lefttree, List *pathkeys,
-										Relids relids,
+static Plan *prepare_sort_from_pathkeys(PlannerInfo *root, Plan *lefttree,
+										List *pathkeys, Relids relids,
 										const AttrNumber *reqColIdx,
 										bool adjust_tlist_in_place,
 										int *p_numsortkeys,
@@ -273,10 +273,13 @@ static Plan *prepare_sort_from_pathkeys(Plan *lefttree, List *pathkeys,
 										Oid **p_sortOperators,
 										Oid **p_collations,
 										bool **p_nullsFirst);
-static Sort *make_sort_from_pathkeys(Plan *lefttree, List *pathkeys,
-									 Relids relids);
-static IncrementalSort *make_incrementalsort_from_pathkeys(Plan *lefttree,
-														   List *pathkeys, Relids relids, int nPresortedCols);
+static Sort *make_sort_from_pathkeys(PlannerInfo *root, Plan *lefttree,
+									 List *pathkeys, Relids relids);
+static IncrementalSort *make_incrementalsort_from_pathkeys(PlannerInfo *root,
+														   Plan *lefttree,
+														   List *pathkeys,
+														   Relids relids,
+														   int nPresortedCols);
 static Sort *make_sort_from_groupcols(List *groupcls,
 									  AttrNumber *grpColIdx,
 									  Plan *lefttree);
@@ -297,7 +300,7 @@ static Group *make_group(List *tlist, List *qual, int numGroupCols,
 						 AttrNumber *grpColIdx, Oid *grpOperators, Oid *grpCollations,
 						 Plan *lefttree);
 static Unique *make_unique_from_sortclauses(Plan *lefttree, List *distinctList);
-static Unique *make_unique_from_pathkeys(Plan *lefttree,
+static Unique *make_unique_from_pathkeys(PlannerInfo *root, Plan *lefttree,
 										 List *pathkeys, int numCols);
 static Gather *make_gather(List *qptlist, List *qpqual,
 						   int nworkers, int rescan_param, bool single_copy, Plan *subplan);
@@ -1285,7 +1288,8 @@ create_append_plan(PlannerInfo *root, AppendPath *best_path, int flags)
 		 * function result; it must be the same plan node.  However, we then
 		 * need to detect whether any tlist entries were added.
 		 */
-		(void) prepare_sort_from_pathkeys((Plan *) plan, pathkeys,
+		(void) prepare_sort_from_pathkeys(root,
+										  (Plan *) plan, pathkeys,
 										  best_path->path.parent->relids,
 										  NULL,
 										  true,
@@ -1329,7 +1333,7 @@ create_append_plan(PlannerInfo *root, AppendPath *best_path, int flags)
 			 * don't need an explicit sort, to make sure they are returning
 			 * the same sort key columns the Append expects.
 			 */
-			subplan = prepare_sort_from_pathkeys(subplan, pathkeys,
+			subplan = prepare_sort_from_pathkeys(root, subplan, pathkeys,
 												 subpath->parent->relids,
 												 nodeSortColIdx,
 												 false,
@@ -1470,7 +1474,7 @@ create_merge_append_plan(PlannerInfo *root, MergeAppendPath *best_path,
 	 * function result; it must be the same plan node.  However, we then need
 	 * to detect whether any tlist entries were added.
 	 */
-	(void) prepare_sort_from_pathkeys(plan, pathkeys,
+	(void) prepare_sort_from_pathkeys(root, plan, pathkeys,
 									  best_path->path.parent->relids,
 									  NULL,
 									  true,
@@ -1501,7 +1505,7 @@ create_merge_append_plan(PlannerInfo *root, MergeAppendPath *best_path,
 		subplan = create_plan_recurse(root, subpath, CP_EXACT_TLIST);
 
 		/* Compute sort column info, and adjust subplan's tlist as needed */
-		subplan = prepare_sort_from_pathkeys(subplan, pathkeys,
+		subplan = prepare_sort_from_pathkeys(root, subplan, pathkeys,
 											 subpath->parent->relids,
 											 node->sortColIdx,
 											 false,
@@ -1981,7 +1985,7 @@ create_gather_merge_plan(PlannerInfo *root, GatherMergePath *best_path)
 	Assert(pathkeys != NIL);
 
 	/* Compute sort column info, and adjust subplan's tlist as needed */
-	subplan = prepare_sort_from_pathkeys(subplan, pathkeys,
+	subplan = prepare_sort_from_pathkeys(root, subplan, pathkeys,
 										 best_path->subpath->parent->relids,
 										 gm_plan->sortColIdx,
 										 false,
@@ -2195,7 +2199,7 @@ create_sort_plan(PlannerInfo *root, SortPath *best_path, int flags)
 	 * relids. Thus, if this sort path is based on a child relation, we must
 	 * pass its relids.
 	 */
-	plan = make_sort_from_pathkeys(subplan, best_path->path.pathkeys,
+	plan = make_sort_from_pathkeys(root, subplan, best_path->path.pathkeys,
 								   IS_OTHER_REL(best_path->subpath->parent) ?
 								   best_path->path.parent->relids : NULL);
 
@@ -2219,7 +2223,7 @@ create_incrementalsort_plan(PlannerInfo *root, IncrementalSortPath *best_path,
 	/* See comments in create_sort_plan() above */
 	subplan = create_plan_recurse(root, best_path->spath.subpath,
 								  flags | CP_SMALL_TLIST);
-	plan = make_incrementalsort_from_pathkeys(subplan,
+	plan = make_incrementalsort_from_pathkeys(root, subplan,
 											  best_path->spath.path.pathkeys,
 											  IS_OTHER_REL(best_path->spath.subpath->parent) ?
 											  best_path->spath.path.parent->relids : NULL,
@@ -2288,7 +2292,7 @@ create_upper_unique_plan(PlannerInfo *root, UpperUniquePath *best_path, int flag
 	subplan = create_plan_recurse(root, best_path->subpath,
 								  flags | CP_LABEL_TLIST);
 
-	plan = make_unique_from_pathkeys(subplan,
+	plan = make_unique_from_pathkeys(root, subplan,
 									 best_path->path.pathkeys,
 									 best_path->numkeys);
 
@@ -4554,7 +4558,8 @@ create_mergejoin_plan(PlannerInfo *root,
 		if (!use_incremental_sort)
 		{
 			sort_plan = (Plan *)
-				make_sort_from_pathkeys(outer_plan,
+				make_sort_from_pathkeys(root,
+										outer_plan,
 										best_path->outersortkeys,
 										outer_relids);
 
@@ -4563,7 +4568,8 @@ create_mergejoin_plan(PlannerInfo *root,
 		else
 		{
 			sort_plan = (Plan *)
-				make_incrementalsort_from_pathkeys(outer_plan,
+				make_incrementalsort_from_pathkeys(root,
+												   outer_plan,
 												   best_path->outersortkeys,
 												   outer_relids,
 												   presorted_keys);
@@ -4588,7 +4594,7 @@ create_mergejoin_plan(PlannerInfo *root,
 		 */
 
 		Relids		inner_relids = inner_path->parent->relids;
-		Sort	   *sort = make_sort_from_pathkeys(inner_plan,
+		Sort	   *sort = make_sort_from_pathkeys(root, inner_plan,
 												   best_path->innersortkeys,
 												   inner_relids);
 
@@ -6238,7 +6244,8 @@ make_incrementalsort(Plan *lefttree, int numCols, int nPresortedCols,
  * or a Result stacked atop lefttree).
  */
 static Plan *
-prepare_sort_from_pathkeys(Plan *lefttree, List *pathkeys,
+prepare_sort_from_pathkeys(PlannerInfo *root,
+						   Plan *lefttree, List *pathkeys,
 						   Relids relids,
 						   const AttrNumber *reqColIdx,
 						   bool adjust_tlist_in_place,
@@ -6305,7 +6312,7 @@ prepare_sort_from_pathkeys(Plan *lefttree, List *pathkeys,
 			tle = get_tle_by_resno(tlist, reqColIdx[numsortkeys]);
 			if (tle)
 			{
-				em = find_ec_member_matching_expr(ec, tle->expr, relids);
+				em = find_ec_member_matching_expr(root, ec, tle->expr, relids);
 				if (em)
 				{
 					/* found expr at right place in tlist */
@@ -6333,7 +6340,7 @@ prepare_sort_from_pathkeys(Plan *lefttree, List *pathkeys,
 			foreach(j, tlist)
 			{
 				tle = (TargetEntry *) lfirst(j);
-				em = find_ec_member_matching_expr(ec, tle->expr, relids);
+				em = find_ec_member_matching_expr(root, ec, tle->expr, relids);
 				if (em)
 				{
 					/* found expr already in tlist */
@@ -6349,7 +6356,7 @@ prepare_sort_from_pathkeys(Plan *lefttree, List *pathkeys,
 			/*
 			 * No matching tlist item; look for a computable expression.
 			 */
-			em = find_computable_ec_member(NULL, ec, tlist, relids, false);
+			em = find_computable_ec_member(root, ec, tlist, relids, false);
 			if (!em)
 				elog(ERROR, "could not find pathkey item to sort");
 			pk_datatype = em->em_datatype;
@@ -6420,7 +6427,8 @@ prepare_sort_from_pathkeys(Plan *lefttree, List *pathkeys,
  *	  'relids' is the set of relations required by prepare_sort_from_pathkeys()
  */
 static Sort *
-make_sort_from_pathkeys(Plan *lefttree, List *pathkeys, Relids relids)
+make_sort_from_pathkeys(PlannerInfo *root, Plan *lefttree, List *pathkeys,
+						Relids relids)
 {
 	int			numsortkeys;
 	AttrNumber *sortColIdx;
@@ -6429,7 +6437,9 @@ make_sort_from_pathkeys(Plan *lefttree, List *pathkeys, Relids relids)
 	bool	   *nullsFirst;
 
 	/* Compute sort column info, and adjust lefttree as needed */
-	lefttree = prepare_sort_from_pathkeys(lefttree, pathkeys,
+	lefttree = prepare_sort_from_pathkeys(root,
+										  lefttree,
+										  pathkeys,
 										  relids,
 										  NULL,
 										  false,
@@ -6455,7 +6465,8 @@ make_sort_from_pathkeys(Plan *lefttree, List *pathkeys, Relids relids)
  *	  'nPresortedCols' is the number of presorted columns in input tuples
  */
 static IncrementalSort *
-make_incrementalsort_from_pathkeys(Plan *lefttree, List *pathkeys,
+make_incrementalsort_from_pathkeys(PlannerInfo *root,
+								   Plan *lefttree, List *pathkeys,
 								   Relids relids, int nPresortedCols)
 {
 	int			numsortkeys;
@@ -6465,7 +6476,9 @@ make_incrementalsort_from_pathkeys(Plan *lefttree, List *pathkeys,
 	bool	   *nullsFirst;
 
 	/* Compute sort column info, and adjust lefttree as needed */
-	lefttree = prepare_sort_from_pathkeys(lefttree, pathkeys,
+	lefttree = prepare_sort_from_pathkeys(root,
+										  lefttree,
+										  pathkeys,
 										  relids,
 										  NULL,
 										  false,
@@ -6824,7 +6837,8 @@ make_unique_from_sortclauses(Plan *lefttree, List *distinctList)
  * as above, but use pathkeys to identify the sort columns and semantics
  */
 static Unique *
-make_unique_from_pathkeys(Plan *lefttree, List *pathkeys, int numCols)
+make_unique_from_pathkeys(PlannerInfo *root, Plan *lefttree, List *pathkeys,
+						  int numCols)
 {
 	Unique	   *node = makeNode(Unique);
 	Plan	   *plan = &node->plan;
@@ -6887,7 +6901,7 @@ make_unique_from_pathkeys(Plan *lefttree, List *pathkeys, int numCols)
 			foreach(j, plan->targetlist)
 			{
 				tle = (TargetEntry *) lfirst(j);
-				em = find_ec_member_matching_expr(ec, tle->expr, NULL);
+				em = find_ec_member_matching_expr(root, ec, tle->expr, NULL);
 				if (em)
 				{
 					/* found expr already in tlist */
diff --git a/src/backend/optimizer/plan/planagg.c b/src/backend/optimizer/plan/planagg.c
index 64605be3178..ca5cb79a680 100644
--- a/src/backend/optimizer/plan/planagg.c
+++ b/src/backend/optimizer/plan/planagg.c
@@ -356,6 +356,7 @@ build_minmax_path(PlannerInfo *root, MinMaxAggInfo *mminfo,
 	Assert(subroot->join_info_list == NIL);
 	/* and we haven't made equivalence classes, either */
 	Assert(subroot->eq_classes == NIL);
+	Assert(root->eq_members == NIL);
 	/* and we haven't created PlaceHolderInfos, either */
 	Assert(subroot->placeholder_list == NIL);
 
diff --git a/src/backend/optimizer/plan/planner.c b/src/backend/optimizer/plan/planner.c
index e92e108b6b6..f25a6ece2fc 100644
--- a/src/backend/optimizer/plan/planner.c
+++ b/src/backend/optimizer/plan/planner.c
@@ -661,6 +661,9 @@ subquery_planner(PlannerGlobal *glob, Query *parse, PlannerInfo *parent_root,
 	root->multiexpr_params = NIL;
 	root->join_domains = NIL;
 	root->eq_classes = NIL;
+	root->eq_members = NIL;
+	root->eq_sources = NIL;
+	root->eq_derives = NIL;
 	root->ec_merging_done = false;
 	root->last_rinfo_serial = 0;
 	root->all_result_relids =
diff --git a/src/backend/optimizer/prep/prepjointree.c b/src/backend/optimizer/prep/prepjointree.c
index 82775a3dd51..3bbace3329d 100644
--- a/src/backend/optimizer/prep/prepjointree.c
+++ b/src/backend/optimizer/prep/prepjointree.c
@@ -1153,6 +1153,9 @@ pull_up_simple_subquery(PlannerInfo *root, Node *jtnode, RangeTblEntry *rte,
 	subroot->multiexpr_params = NIL;
 	subroot->join_domains = NIL;
 	subroot->eq_classes = NIL;
+	subroot->eq_members = NIL;
+	subroot->eq_sources = NIL;
+	subroot->eq_derives = NIL;
 	subroot->ec_merging_done = false;
 	subroot->last_rinfo_serial = 0;
 	subroot->all_result_relids = NULL;
diff --git a/src/backend/optimizer/prep/prepunion.c b/src/backend/optimizer/prep/prepunion.c
index 7c27dc24e21..8d6678e9922 100644
--- a/src/backend/optimizer/prep/prepunion.c
+++ b/src/backend/optimizer/prep/prepunion.c
@@ -37,7 +37,7 @@
 #include "parser/parse_coerce.h"
 #include "utils/selfuncs.h"
 
-
+static void setup_append_rel_entry(PlannerInfo *root);
 static RelOptInfo *recurse_set_operations(Node *setOp, PlannerInfo *root,
 										  SetOperationStmt *parentOp,
 										  List *colTypes, List *colCollations,
@@ -117,6 +117,7 @@ plan_set_operations(PlannerInfo *root)
 	 * merging.  Mark that merging is complete to allow us to make pathkeys.
 	 */
 	Assert(root->eq_classes == NIL);
+	Assert(root->eq_members == NIL);
 	root->ec_merging_done = true;
 
 	/*
@@ -138,6 +139,8 @@ plan_set_operations(PlannerInfo *root)
 	leftmostQuery = leftmostRTE->subquery;
 	Assert(leftmostQuery != NULL);
 
+	setup_append_rel_entry(root);
+
 	/*
 	 * If the topmost node is a recursive union, it needs special processing.
 	 */
@@ -170,6 +173,26 @@ plan_set_operations(PlannerInfo *root)
 	return setop_rel;
 }
 
+/*
+ * setup_append_rel_entry
+ *		Add entry into root's simple_rte_array at element 0.  This is required
+ *		because generate_append_tlist() makes Vars with varno=0.  In
+ *		add_eq_member() we need to index EquivalenceMembers belonging to this
+ *		relation.
+ */
+static void
+setup_append_rel_entry(PlannerInfo *root)
+{
+	RangeTblEntry *rte = makeNode(RangeTblEntry);
+
+	memset(rte, 0, sizeof(RangeTblEntry));
+	rte->eclass_member_indexes = NULL;
+
+	/* make sure nothing else has made use of this element */
+	Assert(root->simple_rte_array[0] == NULL);
+	root->simple_rte_array[0] = rte;
+}
+
 /*
  * recurse_set_operations
  *	  Recursively handle one step in a tree of set operations
diff --git a/src/backend/optimizer/util/inherit.c b/src/backend/optimizer/util/inherit.c
index 17e51cd75d7..a5d9357bc68 100644
--- a/src/backend/optimizer/util/inherit.c
+++ b/src/backend/optimizer/util/inherit.c
@@ -491,6 +491,14 @@ expand_single_inheritance_child(PlannerInfo *root, RangeTblEntry *parentrte,
 	 */
 	childrte = makeNode(RangeTblEntry);
 	memcpy(childrte, parentrte, sizeof(RangeTblEntry));
+	/*
+	 * We do not want to inherit the EquivalenceMember indexes of the parent
+	 * to its child
+	 */
+	childrte->eclass_member_indexes = NULL;
+	childrte->eclass_source_indexes = NULL;
+	childrte->eclass_derive_indexes = NULL;
+
 	Assert(parentrte->rtekind == RTE_RELATION); /* else this is dubious */
 	childrte->relid = childOID;
 	childrte->relkind = childrel->rd_rel->relkind;
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index 38d6ad7dcbd..2be219ff36b 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -1247,6 +1247,15 @@ typedef struct RangeTblEntry
 	bool		inFromCl pg_node_attr(query_jumble_ignore);
 	/* security barrier quals to apply, if any */
 	List	   *securityQuals pg_node_attr(query_jumble_ignore);
+	Bitmapset  *eclass_member_indexes;	/* Indexes in PlannerInfo's eq_members
+										 * list of EquivalenceMembers that
+										 * mention this relation */
+	Bitmapset  *eclass_source_indexes;	/* Indexes in PlannerInfo's eq_sources
+										 * list for RestrictInfos that mention
+										 * this relation */
+	Bitmapset  *eclass_derive_indexes;	/* Indexes in PlannerInfo's eq_derives
+										 * list for RestrictInfos that mention
+										 * this relation */
 } RangeTblEntry;
 
 /*
diff --git a/src/include/nodes/pathnodes.h b/src/include/nodes/pathnodes.h
index 54ee17697e5..8be0b00df15 100644
--- a/src/include/nodes/pathnodes.h
+++ b/src/include/nodes/pathnodes.h
@@ -313,6 +313,15 @@ struct PlannerInfo
 	/* list of active EquivalenceClasses */
 	List	   *eq_classes;
 
+	/* list of each EquivalenceMember */
+	List	   *eq_members;
+
+	/* list of source RestrictInfos used to build EquivalenceClasses */
+	List	   *eq_sources;
+
+	/* list of RestrictInfos derived from EquivalenceClasses */
+	List	   *eq_derives;
+
 	/* set true once ECs are canonical */
 	bool		ec_merging_done;
 
@@ -950,6 +959,7 @@ typedef struct RelOptInfo
 	double		allvisfrac;
 	/* indexes in PlannerInfo's eq_classes list of ECs that mention this rel */
 	Bitmapset  *eclass_indexes;
+
 	PlannerInfo *subroot;		/* if subquery */
 	List	   *subplan_params; /* if subquery */
 	/* wanted number of parallel workers */
@@ -1376,6 +1386,39 @@ typedef struct JoinDomain
  * entry: consider SELECT random() AS a, random() AS b ... ORDER BY b,a.
  * So we record the SortGroupRef of the originating sort clause.
  *
+ * At various locations in the query planner, we must search for
+ * EquivalenceMembers within a given EquivalenceClass.  For the common case,
+ * an EquivalenceClass does not have a large number of EquivalenceMembers,
+ * however, in cases such as planning queries to partitioned tables, the number
+ * of members can become large.  To maintain planning performance, we make use
+ * of a bitmap index to allow us to quickly find EquivalenceMembers in a given
+ * EquivalenceClass belonging to a given relation or set of relations.  This
+ * is done by storing a list of EquivalenceMembers belonging to all
+ * EquivalenceClasses in PlannerInfo and storing a Bitmapset for each
+ * RelOptInfo which has a bit set for each EquivalenceMember in that list
+ * which relates to the given relation.  We also store a Bitmapset to mark all
+ * of the indexes in the PlannerInfo's list of EquivalenceMembers in the
+ * EquivalenceClass.  We can quickly find the interesting indexes into the
+ * PlannerInfo's list by performing a bit-wise AND on the RelOptInfo's
+ * Bitmapset and the EquivalenceClasses.
+ *
+ * To further speed up the lookup of EquivalenceMembers we also record the
+ * non-child indexes.  This allows us to deal with fewer bits for searches
+ * that don't require "is_child" EquivalenceMembers.  We must also store the
+ * indexes into EquivalenceMembers which have no relids mentioned as some
+ * searches require that.
+ *
+ * Additionally, we also store the EquivalenceMembers of a given
+ * EquivalenceClass in the ec_members list.  Technically, we could obtain this
+ * from looking at the bits in ec_member_indexes, however, finding all members
+ * of a given EquivalenceClass is common enough that it pays to have fast
+ * access to a dense list containing all members.
+ *
+ * The source and derived RestrictInfos are indexed in a similar method,
+ * although we don't maintain a List in the EquivalenceClass for these.  These
+ * must be looked up in PlannerInfo using the ec_source_indexes and
+ * ec_derive_indexes Bitmapsets.
+ *
  * NB: if ec_merged isn't NULL, this class has been merged into another, and
  * should be ignored in favor of using the pointed-to class.
  *
@@ -1393,9 +1436,19 @@ typedef struct EquivalenceClass
 
 	List	   *ec_opfamilies;	/* btree operator family OIDs */
 	Oid			ec_collation;	/* collation, if datatypes are collatable */
-	List	   *ec_members;		/* list of EquivalenceMembers */
-	List	   *ec_sources;		/* list of generating RestrictInfos */
-	List	   *ec_derives;		/* list of derived RestrictInfos */
+	List	   *ec_members;		/* list of EquivalenceMembers in the class */
+	Bitmapset  *ec_member_indexes;	/* Indexes into all PlannerInfos
+									 * eq_members for this EquivalenceClass */
+	Bitmapset  *ec_nonchild_indexes;	/* Indexes into PlannerInfo's
+										 * eq_members with em_is_child ==
+										 * false */
+	Bitmapset  *ec_norel_indexes;	/* Indexes into PlannerInfo's eq_members
+									 * for members where pull_varno on the
+									 * em_expr is an empty set */
+	Bitmapset  *ec_source_indexes;	/* indexes into PlannerInfo's eq_sources
+									 * list of generating RestrictInfos */
+	Bitmapset  *ec_derive_indexes;	/* indexes into PlannerInfo's eq_derives
+									 * list of derived RestrictInfos */
 	Relids		ec_relids;		/* all relids appearing in ec_members, except
 								 * for child members (see below) */
 	bool		ec_has_const;	/* any pseudoconstants in ec_members? */
@@ -1443,8 +1496,10 @@ typedef struct EquivalenceMember
 	NodeTag		type;
 
 	Expr	   *em_expr;		/* the expression represented */
-	Relids		em_relids;		/* all relids appearing in em_expr */
-	bool		em_is_const;	/* expression is pseudoconstant? */
+	int			em_index;		/* index in root->eq_members */
+	Relids		em_relids;		/* relids for this member */
+	bool		em_is_const;	/* is em_relids empty? */
+	bool		em_norel_expr;	/* true if em_expr contains no Vars */
 	bool		em_is_child;	/* derived version for a child relation? */
 	Oid			em_datatype;	/* the "nominal type" used by the opfamily */
 	JoinDomain *em_jdomain;		/* join domain containing the source clause */
diff --git a/src/include/nodes/pg_list.h b/src/include/nodes/pg_list.h
index a872fc501e0..7bc29752b85 100644
--- a/src/include/nodes/pg_list.h
+++ b/src/include/nodes/pg_list.h
@@ -680,6 +680,7 @@ extern pg_nodiscard List *list_copy_deep(const List *oldlist);
 typedef int (*list_sort_comparator) (const ListCell *a, const ListCell *b);
 extern void list_sort(List *list, list_sort_comparator cmp);
 
+extern int	list_ptr_cmp(const ListCell *p1, const ListCell *p2);
 extern int	list_int_cmp(const ListCell *p1, const ListCell *p2);
 extern int	list_oid_cmp(const ListCell *p1, const ListCell *p2);
 
diff --git a/src/include/optimizer/paths.h b/src/include/optimizer/paths.h
index 46955d128f0..140027ab21f 100644
--- a/src/include/optimizer/paths.h
+++ b/src/include/optimizer/paths.h
@@ -116,6 +116,31 @@ extern void init_dummy_sjinfo(SpecialJoinInfo *sjinfo, Relids left_relids,
  * equivclass.c
  *	  routines for managing EquivalenceClasses
  */
+
+/*
+ * EquivalenceMemberIterator
+ *		Data structure used for iteration over an EquivalenceClass's
+ *		EquivalenceMember in order to quickly find the members matching our
+ *		search pattern.
+ */
+typedef struct EquivalenceMemberIterator
+{
+	bool		use_index;		/* use matching_ems index? */
+	bool		relids_empty;	/* is with_relids empty? */
+	bool		with_children;	/* include em_is_child members? */
+	bool		with_norel_members; /* include members with empty em_relids */
+#ifdef USE_ASSERT_CHECKING
+	bool		isstrict;		/* ensure the correct next function is used */
+#endif
+	int			orig_length;	/* elements in eclass->ec_members at the start */
+	int			current_index;	/* current iterator position, or -1. */
+	Relids		with_relids;	/* relids to match in em_relids */
+	PlannerInfo *root;			/* PlannerInfo the eclass belongs to */
+	EquivalenceClass *eclass;	/* the EquivalenceClass we're looking at */
+	Bitmapset  *matching_ems;	/* when use_index == true, these are the
+								 * matching indexes in root eq_members */
+} EquivalenceMemberIterator;
+
 typedef bool (*ec_matches_callback_type) (PlannerInfo *root,
 										  RelOptInfo *rel,
 										  EquivalenceClass *ec,
@@ -137,7 +162,8 @@ extern EquivalenceClass *get_eclass_for_sort_expr(PlannerInfo *root,
 												  Index sortref,
 												  Relids rel,
 												  bool create_it);
-extern EquivalenceMember *find_ec_member_matching_expr(EquivalenceClass *ec,
+extern EquivalenceMember *find_ec_member_matching_expr(PlannerInfo *root,
+													   EquivalenceClass *ec,
 													   Expr *expr,
 													   Relids relids);
 extern EquivalenceMember *find_computable_ec_member(PlannerInfo *root,
@@ -164,7 +190,8 @@ extern bool exprs_known_equal(PlannerInfo *root, Node *item1, Node *item2,
 extern EquivalenceClass *match_eclasses_to_foreign_key_col(PlannerInfo *root,
 														   ForeignKeyOptInfo *fkinfo,
 														   int colno);
-extern RestrictInfo *find_derived_clause_for_ec_member(EquivalenceClass *ec,
+extern RestrictInfo *find_derived_clause_for_ec_member(PlannerInfo *root,
+													   EquivalenceClass *ec,
 													   EquivalenceMember *em);
 extern void add_child_rel_equivalences(PlannerInfo *root,
 									   AppendRelInfo *appinfo,
@@ -194,6 +221,42 @@ extern bool eclass_useful_for_merging(PlannerInfo *root,
 extern bool is_redundant_derived_clause(RestrictInfo *rinfo, List *clauselist);
 extern bool is_redundant_with_indexclauses(RestrictInfo *rinfo,
 										   List *indexclauses);
+extern Bitmapset *get_ecmember_indexes(PlannerInfo *root,
+									   EquivalenceClass *ec,
+									   Relids relids,
+									   bool with_children,
+									   bool with_norel_members);
+extern Bitmapset *get_ecmember_indexes_strict(PlannerInfo *root,
+											  EquivalenceClass *ec,
+											  Relids relids,
+											  bool with_children,
+											  bool with_norel_members);
+extern void setup_eclass_member_iterator(EquivalenceMemberIterator *iter,
+										 PlannerInfo *root,
+										 EquivalenceClass *ec, Relids relids,
+										 bool with_children,
+										 bool with_norel_members);
+extern void setup_eclass_member_strict_iterator(EquivalenceMemberIterator *iter,
+												PlannerInfo *root,
+												EquivalenceClass *ec,
+												Relids relids,
+												bool with_children,
+												bool with_norel_members);
+extern EquivalenceMember *eclass_member_iterator_next(EquivalenceMemberIterator *iter);
+extern EquivalenceMember *eclass_member_iterator_strict_next(EquivalenceMemberIterator *iter);
+extern void eclass_member_iterator_dispose(EquivalenceMemberIterator *iter);
+extern Bitmapset *get_ec_source_indexes(PlannerInfo *root,
+										EquivalenceClass *ec,
+										Relids relids);
+extern Bitmapset *get_ec_source_indexes_strict(PlannerInfo *root,
+											   EquivalenceClass *ec,
+											   Relids relids);
+extern Bitmapset *get_ec_derive_indexes(PlannerInfo *root,
+										EquivalenceClass *ec,
+										Relids relids);
+extern Bitmapset *get_ec_derive_indexes_strict(PlannerInfo *root,
+											   EquivalenceClass *ec,
+											   Relids relids);
 
 /*
  * pathkeys.c
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index e1c4f913f84..f44ab1c2140 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -687,6 +687,7 @@ EphemeralNamedRelationMetadata
 EphemeralNamedRelationMetadataData
 EquivalenceClass
 EquivalenceMember
+EquivalenceMemberIterator
 ErrorContextCallback
 ErrorData
 ErrorSaveContext