[CF 3701] v42 - Reducing planning time when tables have many partitions

This branch was automatically generated by a robot using patches from an
email thread registered at:

https://commitfest.postgresql.org/patch/3701

The branch will be overwritten each time a new patch version is posted to
the thread, and also periodically to check for bitrot caused by changes
on the master branch.

Patch(es): https://www.postgresql.org/message-id/CAApHDvpf+2rUi3rOepS9jMjiS3ezH9VcZisS+A+Ob5G5YpBZxg@mail.gmail.com
Author(s): Yuya Watari

Author: Commitfest Bot

contrib/postgres_fdw/postgres_fdw.c

@@ -7847,14 +7847,13 @@ conversion_error_callback(void *arg)
 EquivalenceMember *
 find_em_for_rel(PlannerInfo *root, EquivalenceClass *ec, RelOptInfo *rel)
 {
-	ListCell   *lc;
-
 	PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) rel->fdw_private;
+	EquivalenceMemberIterator it;
+	EquivalenceMember *em;
 
-	foreach(lc, ec->ec_members)
+	setup_eclass_member_iterator(&it, ec, rel->relids);
+	while ((em = eclass_member_iterator_next(&it)) != NULL)
 	{
-		EquivalenceMember *em = (EquivalenceMember *) lfirst(lc);
-
 		/*
 		 * Note we require !bms_is_empty, else we'd accept constant
 		 * expressions which are not suitable for the purpose.
@@ -7908,7 +7907,10 @@ find_em_for_rel_target(PlannerInfo *root, EquivalenceClass *ec,
 		while (expr && IsA(expr, RelabelType))
 			expr = ((RelabelType *) expr)->arg;
 
-		/* Locate an EquivalenceClass member matching this expr, if any */
+		/*
+		 * Locate an EquivalenceClass member matching this expr, if any.
+		 * Ignore child members.
+		 */
 		foreach(lc2, ec->ec_members)
 		{
 			EquivalenceMember *em = (EquivalenceMember *) lfirst(lc2);
@@ -7918,9 +7920,8 @@ find_em_for_rel_target(PlannerInfo *root, EquivalenceClass *ec,
 			if (em->em_is_const)
 				continue;
 
-			/* Ignore child members */
-			if (em->em_is_child)
-				continue;
+			/* Child members should not exist in ec_members */
+			Assert(!em->em_is_child);
 
 			/* Match if same expression (after stripping relabel) */
 			em_expr = em->em_expr;

src/backend/nodes/outfuncs.c

@@ -465,7 +465,9 @@ _outEquivalenceClass(StringInfo str, const EquivalenceClass *node)
 
 	WRITE_NODE_FIELD(ec_opfamilies);
 	WRITE_OID_FIELD(ec_collation);
+	WRITE_INT_FIELD(ec_childmembers_size);
 	WRITE_NODE_FIELD(ec_members);
+	WRITE_NODE_ARRAY(ec_childmembers, node->ec_childmembers_size);
 	WRITE_NODE_FIELD(ec_sources);
 	/* Only ec_derives_list is written; hash is not serialized. */
 	WRITE_NODE_FIELD(ec_derives_list);