Speed up planning when partitions can be pruned at plan time.

Previously, the planner created RangeTblEntry and RelOptInfo structs
for every partition of a partitioned table, even though many of them
might later be deemed uninteresting thanks to partition pruning logic.
This incurred significant overhead when there are many partitions.
Arrange to postpone creation of these data structures until after
we've processed the query enough to identify restriction quals for
the partitioned table, and then apply partition pruning before not
after creation of each partition's data structures.  In this way
we need not open the partition relations at all for partitions that
the planner has no real interest in.

For queries that can be proven at plan time to access only a small
number of partitions, this patch improves the practical maximum
number of partitions from under 100 to perhaps a few thousand.

Amit Langote, reviewed at various times by Dilip Kumar, Jesper Pedersen,
Yoshikazu Imai, and David Rowley

Discussion: https://postgr.es/m/9d7c5112-cb99-6a47-d3be-cf1ee6862a1d@lab.ntt.co.jp

contrib/postgres_fdw/expected/postgres_fdw.out

@@ -7141,9 +7141,9 @@ select * from bar where f1 in (select f1 from foo) for update;
                                           QUERY PLAN                                          
 ----------------------------------------------------------------------------------------------
  LockRows
-   Output: bar.f1, bar.f2, bar.ctid, bar.*, bar.tableoid, foo.ctid, foo.*, foo.tableoid
+   Output: bar.f1, bar.f2, bar.ctid, foo.ctid, bar.*, bar.tableoid, foo.*, foo.tableoid
    ->  Hash Join
-         Output: bar.f1, bar.f2, bar.ctid, bar.*, bar.tableoid, foo.ctid, foo.*, foo.tableoid
+         Output: bar.f1, bar.f2, bar.ctid, foo.ctid, bar.*, bar.tableoid, foo.*, foo.tableoid
          Inner Unique: true
          Hash Cond: (bar.f1 = foo.f1)
          ->  Append
@@ -7153,15 +7153,15 @@ select * from bar where f1 in (select f1 from foo) for update;
                      Output: bar2.f1, bar2.f2, bar2.ctid, bar2.*, bar2.tableoid
                      Remote SQL: SELECT f1, f2, f3, ctid FROM public.loct2 FOR UPDATE
          ->  Hash
-               Output: foo.ctid, foo.*, foo.tableoid, foo.f1
+               Output: foo.ctid, foo.f1, foo.*, foo.tableoid
                ->  HashAggregate
-                     Output: foo.ctid, foo.*, foo.tableoid, foo.f1
+                     Output: foo.ctid, foo.f1, foo.*, foo.tableoid
                      Group Key: foo.f1
                      ->  Append
                            ->  Seq Scan on public.foo
-                                 Output: foo.ctid, foo.*, foo.tableoid, foo.f1
+                                 Output: foo.ctid, foo.f1, foo.*, foo.tableoid
                            ->  Foreign Scan on public.foo2
-                                 Output: foo2.ctid, foo2.*, foo2.tableoid, foo2.f1
+                                 Output: foo2.ctid, foo2.f1, foo2.*, foo2.tableoid
                                  Remote SQL: SELECT f1, f2, f3, ctid FROM public.loct1
 (23 rows)
 
@@ -7179,9 +7179,9 @@ select * from bar where f1 in (select f1 from foo) for share;
                                           QUERY PLAN                                          
 ----------------------------------------------------------------------------------------------
  LockRows
-   Output: bar.f1, bar.f2, bar.ctid, bar.*, bar.tableoid, foo.ctid, foo.*, foo.tableoid
+   Output: bar.f1, bar.f2, bar.ctid, foo.ctid, bar.*, bar.tableoid, foo.*, foo.tableoid
    ->  Hash Join
-         Output: bar.f1, bar.f2, bar.ctid, bar.*, bar.tableoid, foo.ctid, foo.*, foo.tableoid
+         Output: bar.f1, bar.f2, bar.ctid, foo.ctid, bar.*, bar.tableoid, foo.*, foo.tableoid
          Inner Unique: true
          Hash Cond: (bar.f1 = foo.f1)
          ->  Append
@@ -7191,15 +7191,15 @@ select * from bar where f1 in (select f1 from foo) for share;
                      Output: bar2.f1, bar2.f2, bar2.ctid, bar2.*, bar2.tableoid
                      Remote SQL: SELECT f1, f2, f3, ctid FROM public.loct2 FOR SHARE
          ->  Hash
-               Output: foo.ctid, foo.*, foo.tableoid, foo.f1
+               Output: foo.ctid, foo.f1, foo.*, foo.tableoid
                ->  HashAggregate
-                     Output: foo.ctid, foo.*, foo.tableoid, foo.f1
+                     Output: foo.ctid, foo.f1, foo.*, foo.tableoid
                      Group Key: foo.f1
                      ->  Append
                            ->  Seq Scan on public.foo
-                                 Output: foo.ctid, foo.*, foo.tableoid, foo.f1
+                                 Output: foo.ctid, foo.f1, foo.*, foo.tableoid
                            ->  Foreign Scan on public.foo2
-                                 Output: foo2.ctid, foo2.*, foo2.tableoid, foo2.f1
+                                 Output: foo2.ctid, foo2.f1, foo2.*, foo2.tableoid
                                  Remote SQL: SELECT f1, f2, f3, ctid FROM public.loct1
 (23 rows)
 
@@ -7228,15 +7228,15 @@ update bar set f2 = f2 + 100 where f1 in (select f1 from foo);
          ->  Seq Scan on public.bar
                Output: bar.f1, bar.f2, bar.ctid
          ->  Hash
-               Output: foo.ctid, foo.*, foo.tableoid, foo.f1
+               Output: foo.ctid, foo.f1, foo.*, foo.tableoid
                ->  HashAggregate
-                     Output: foo.ctid, foo.*, foo.tableoid, foo.f1
+                     Output: foo.ctid, foo.f1, foo.*, foo.tableoid
                      Group Key: foo.f1
                      ->  Append
                            ->  Seq Scan on public.foo
-                                 Output: foo.ctid, foo.*, foo.tableoid, foo.f1
+                                 Output: foo.ctid, foo.f1, foo.*, foo.tableoid
                            ->  Foreign Scan on public.foo2
-                                 Output: foo2.ctid, foo2.*, foo2.tableoid, foo2.f1
+                                 Output: foo2.ctid, foo2.f1, foo2.*, foo2.tableoid
                                  Remote SQL: SELECT f1, f2, f3, ctid FROM public.loct1
    ->  Hash Join
          Output: bar2.f1, (bar2.f2 + 100), bar2.f3, bar2.ctid, foo.ctid, foo.*, foo.tableoid
@@ -7246,15 +7246,15 @@ update bar set f2 = f2 + 100 where f1 in (select f1 from foo);
                Output: bar2.f1, bar2.f2, bar2.f3, bar2.ctid
                Remote SQL: SELECT f1, f2, f3, ctid FROM public.loct2 FOR UPDATE
          ->  Hash
-               Output: foo.ctid, foo.*, foo.tableoid, foo.f1
+               Output: foo.ctid, foo.f1, foo.*, foo.tableoid
                ->  HashAggregate
-                     Output: foo.ctid, foo.*, foo.tableoid, foo.f1
+                     Output: foo.ctid, foo.f1, foo.*, foo.tableoid
                      Group Key: foo.f1
                      ->  Append
                            ->  Seq Scan on public.foo
-                                 Output: foo.ctid, foo.*, foo.tableoid, foo.f1
+                                 Output: foo.ctid, foo.f1, foo.*, foo.tableoid
                            ->  Foreign Scan on public.foo2
-                                 Output: foo2.ctid, foo2.*, foo2.tableoid, foo2.f1
+                                 Output: foo2.ctid, foo2.f1, foo2.*, foo2.tableoid
                                  Remote SQL: SELECT f1, f2, f3, ctid FROM public.loct1
 (39 rows)
 
@@ -8460,7 +8460,7 @@ SELECT t1.a,t2.b,t2.c FROM fprt1 t1 LEFT JOIN (SELECT * FROM fprt2 WHERE a < 10)
  Foreign Scan
    Output: t1.a, ftprt2_p1.b, ftprt2_p1.c
    Relations: (public.ftprt1_p1 t1) LEFT JOIN (public.ftprt2_p1 fprt2)
-   Remote SQL: SELECT r5.a, r7.b, r7.c FROM (public.fprt1_p1 r5 LEFT JOIN public.fprt2_p1 r7 ON (((r5.a = r7.b)) AND ((r5.b = r7.a)) AND ((r7.a < 10)))) WHERE ((r5.a < 10)) ORDER BY r5.a ASC NULLS LAST, r7.b ASC NULLS LAST, r7.c ASC NULLS LAST
+   Remote SQL: SELECT r5.a, r6.b, r6.c FROM (public.fprt1_p1 r5 LEFT JOIN public.fprt2_p1 r6 ON (((r5.a = r6.b)) AND ((r5.b = r6.a)) AND ((r6.a < 10)))) WHERE ((r5.a < 10)) ORDER BY r5.a ASC NULLS LAST, r6.b ASC NULLS LAST, r6.c ASC NULLS LAST
 (4 rows)
 
 SELECT t1.a,t2.b,t2.c FROM fprt1 t1 LEFT JOIN (SELECT * FROM fprt2 WHERE a < 10) t2 ON (t1.a = t2.b and t1.b = t2.a) WHERE t1.a < 10 ORDER BY 1,2,3;

src/backend/executor/execPartition.c

@@ -1654,9 +1654,17 @@ ExecCreatePartitionPruneState(PlanState *planstate,
 				memcpy(pprune->subplan_map, pinfo->subplan_map,
 					   sizeof(int) * pinfo->nparts);
 
-				/* Double-check that list of relations has not changed. */
-				Assert(memcmp(partdesc->oids, pinfo->relid_map,
-					   pinfo->nparts * sizeof(Oid)) == 0);
+				/*
+				 * Double-check that the list of unpruned relations has not
+				 * changed.  (Pruned partitions are not in relid_map[].)
+				 */
+#ifdef USE_ASSERT_CHECKING
+				for (int k = 0; k < pinfo->nparts; k++)
+				{
+					Assert(partdesc->oids[k] == pinfo->relid_map[k] ||
+						   pinfo->subplan_map[k] == -1);
+				}
+#endif
 			}
 			else
 			{

src/backend/optimizer/path/allpaths.c

@@ -139,9 +139,6 @@ static void subquery_push_qual(Query *subquery,
 static void recurse_push_qual(Node *setOp, Query *topquery,
 				  RangeTblEntry *rte, Index rti, Node *qual);
 static void remove_unused_subquery_outputs(Query *subquery, RelOptInfo *rel);
-static bool apply_child_basequals(PlannerInfo *root, RelOptInfo *rel,
-					  RelOptInfo *childrel,
-					  RangeTblEntry *childRTE, AppendRelInfo *appinfo);
 
 
 /*
@@ -396,8 +393,9 @@ set_rel_size(PlannerInfo *root, RelOptInfo *rel,
 				else if (rte->relkind == RELKIND_PARTITIONED_TABLE)
 				{
 					/*
-					 * A partitioned table without any partitions is marked as
-					 * a dummy rel.
+					 * We could get here if asked to scan a partitioned table
+					 * with ONLY.  In that case we shouldn't scan any of the
+					 * partitions, so mark it as a dummy rel.
 					 */
 					set_dummy_rel_pathlist(rel);
 				}
@@ -946,8 +944,6 @@ set_append_rel_size(PlannerInfo *root, RelOptInfo *rel,
 	double	   *parent_attrsizes;
 	int			nattrs;
 	ListCell   *l;
-	Relids		live_children = NULL;
-	bool		did_pruning = false;
 
 	/* Guard against stack overflow due to overly deep inheritance tree. */
 	check_stack_depth();
@@ -965,21 +961,6 @@ set_append_rel_size(PlannerInfo *root, RelOptInfo *rel,
 	if (rte->relkind == RELKIND_PARTITIONED_TABLE)
 		rel->partitioned_child_rels = list_make1_int(rti);
 
-	/*
-	 * If the partitioned relation has any baserestrictinfo quals then we
-	 * attempt to use these quals to prune away partitions that cannot
-	 * possibly contain any tuples matching these quals.  In this case we'll
-	 * store the relids of all partitions which could possibly contain a
-	 * matching tuple, and skip anything else in the loop below.
-	 */
-	if (enable_partition_pruning &&
-		rte->relkind == RELKIND_PARTITIONED_TABLE &&
-		rel->baserestrictinfo != NIL)
-	{
-		live_children = prune_append_rel_partitions(rel);
-		did_pruning = true;
-	}
-
 	/*
 	 * If this is a partitioned baserel, set the consider_partitionwise_join
 	 * flag; currently, we only consider partitionwise joins with the baserel
@@ -1034,30 +1015,17 @@ set_append_rel_size(PlannerInfo *root, RelOptInfo *rel,
 		childrel = find_base_rel(root, childRTindex);
 		Assert(childrel->reloptkind == RELOPT_OTHER_MEMBER_REL);
 
-		if (did_pruning && !bms_is_member(appinfo->child_relid, live_children))
-		{
-			/* This partition was pruned; skip it. */
-			set_dummy_rel_pathlist(childrel);
+		/* We may have already proven the child to be dummy. */
+		if (IS_DUMMY_REL(childrel))
 			continue;
-		}
 
 		/*
 		 * We have to copy the parent's targetlist and quals to the child,
-		 * with appropriate substitution of variables.  If any constant false
-		 * or NULL clauses turn up, we can disregard the child right away. If
-		 * not, we can apply constraint exclusion with just the
-		 * baserestrictinfo quals.
+		 * with appropriate substitution of variables.  However, the
+		 * baserestrictinfo quals were already copied/substituted when the
+		 * child RelOptInfo was built.  So we don't need any additional setup
+		 * before applying constraint exclusion.
 		 */
-		if (!apply_child_basequals(root, rel, childrel, childRTE, appinfo))
-		{
-			/*
-			 * Some restriction clause reduced to constant FALSE or NULL after
-			 * substitution, so this child need not be scanned.
-			 */
-			set_dummy_rel_pathlist(childrel);
-			continue;
-		}
-
 		if (relation_excluded_by_constraints(root, childrel, childRTE))
 		{
 			/*
@@ -1069,7 +1037,8 @@ set_append_rel_size(PlannerInfo *root, RelOptInfo *rel,
 		}
 
 		/*
-		 * CE failed, so finish copying/modifying targetlist and join quals.
+		 * Constraint exclusion failed, so copy the parent's join quals and
+		 * targetlist to the child, with appropriate variable substitutions.
 		 *
 		 * NB: the resulting childrel->reltarget->exprs may contain arbitrary
 		 * expressions, which otherwise would not occur in a rel's targetlist.
@@ -3596,133 +3565,6 @@ generate_partitionwise_join_paths(PlannerInfo *root, RelOptInfo *rel)
 	list_free(live_children);
 }
 
-/*
- * apply_child_basequals
- *		Populate childrel's quals based on rel's quals, translating them using
- *		appinfo.
- *
- * If any of the resulting clauses evaluate to false or NULL, we return false
- * and don't apply any quals.  Caller can mark the relation as a dummy rel in
- * this case, since it needn't be scanned.
- *
- * If any resulting clauses evaluate to true, they're unnecessary and we don't
- * apply then.
- */
-static bool
-apply_child_basequals(PlannerInfo *root, RelOptInfo *rel,
-					  RelOptInfo *childrel, RangeTblEntry *childRTE,
-					  AppendRelInfo *appinfo)
-{
-	List	   *childquals;
-	Index		cq_min_security;
-	ListCell   *lc;
-
-	/*
-	 * The child rel's targetlist might contain non-Var expressions, which
-	 * means that substitution into the quals could produce opportunities for
-	 * const-simplification, and perhaps even pseudoconstant quals. Therefore,
-	 * transform each RestrictInfo separately to see if it reduces to a
-	 * constant or pseudoconstant.  (We must process them separately to keep
-	 * track of the security level of each qual.)
-	 */
-	childquals = NIL;
-	cq_min_security = UINT_MAX;
-	foreach(lc, rel->baserestrictinfo)
-	{
-		RestrictInfo *rinfo = (RestrictInfo *) lfirst(lc);
-		Node	   *childqual;
-		ListCell   *lc2;
-
-		Assert(IsA(rinfo, RestrictInfo));
-		childqual = adjust_appendrel_attrs(root,
-										   (Node *) rinfo->clause,
-										   1, &appinfo);
-		childqual = eval_const_expressions(root, childqual);
-		/* check for flat-out constant */
-		if (childqual && IsA(childqual, Const))
-		{
-			if (((Const *) childqual)->constisnull ||
-				!DatumGetBool(((Const *) childqual)->constvalue))
-			{
-				/* Restriction reduces to constant FALSE or NULL */
-				return false;
-			}
-			/* Restriction reduces to constant TRUE, so drop it */
-			continue;
-		}
-		/* might have gotten an AND clause, if so flatten it */
-		foreach(lc2, make_ands_implicit((Expr *) childqual))
-		{
-			Node	   *onecq = (Node *) lfirst(lc2);
-			bool		pseudoconstant;
-
-			/* check for pseudoconstant (no Vars or volatile functions) */
-			pseudoconstant =
-				!contain_vars_of_level(onecq, 0) &&
-				!contain_volatile_functions(onecq);
-			if (pseudoconstant)
-			{
-				/* tell createplan.c to check for gating quals */
-				root->hasPseudoConstantQuals = true;
-			}
-			/* reconstitute RestrictInfo with appropriate properties */
-			childquals = lappend(childquals,
-								 make_restrictinfo((Expr *) onecq,
-												   rinfo->is_pushed_down,
-												   rinfo->outerjoin_delayed,
-												   pseudoconstant,
-												   rinfo->security_level,
-												   NULL, NULL, NULL));
-			/* track minimum security level among child quals */
-			cq_min_security = Min(cq_min_security, rinfo->security_level);
-		}
-	}
-
-	/*
-	 * In addition to the quals inherited from the parent, we might have
-	 * securityQuals associated with this particular child node. (Currently
-	 * this can only happen in appendrels originating from UNION ALL;
-	 * inheritance child tables don't have their own securityQuals, see
-	 * expand_inherited_rtentry().)	Pull any such securityQuals up into the
-	 * baserestrictinfo for the child.  This is similar to
-	 * process_security_barrier_quals() for the parent rel, except that we
-	 * can't make any general deductions from such quals, since they don't
-	 * hold for the whole appendrel.
-	 */
-	if (childRTE->securityQuals)
-	{
-		Index		security_level = 0;
-
-		foreach(lc, childRTE->securityQuals)
-		{
-			List	   *qualset = (List *) lfirst(lc);
-			ListCell   *lc2;
-
-			foreach(lc2, qualset)
-			{
-				Expr	   *qual = (Expr *) lfirst(lc2);
-
-				/* not likely that we'd see constants here, so no check */
-				childquals = lappend(childquals,
-									 make_restrictinfo(qual,
-													   true, false, false,
-													   security_level,
-													   NULL, NULL, NULL));
-				cq_min_security = Min(cq_min_security, security_level);
-			}
-			security_level++;
-		}
-		Assert(security_level <= root->qual_security_level);
-	}
-
-	/*
-	 * OK, we've got all the baserestrictinfo quals for this child.
-	 */
-	childrel->baserestrictinfo = childquals;
-	childrel->baserestrict_min_security = cq_min_security;
-
-	return true;
-}
 
 /*****************************************************************************
  *			DEBUG SUPPORT

src/backend/optimizer/plan/initsplan.c

@@ -20,6 +20,7 @@
 #include "nodes/nodeFuncs.h"
 #include "optimizer/clauses.h"
 #include "optimizer/cost.h"
+#include "optimizer/inherit.h"
 #include "optimizer/joininfo.h"
 #include "optimizer/optimizer.h"
 #include "optimizer/pathnode.h"
@@ -159,12 +160,7 @@ add_other_rels_to_query(PlannerInfo *root)
 
 		/* If it's marked as inheritable, look for children. */
 		if (rte->inh)
-		{
-			/* Only relation and subquery RTEs can have children. */
-			Assert(rte->rtekind == RTE_RELATION ||
-				   rte->rtekind == RTE_SUBQUERY);
-			add_appendrel_other_rels(root, rel, rti);
-		}
+			expand_inherited_rtentry(root, rel, rte, rti);
 	}
 }
 

src/backend/optimizer/plan/planner.c

@@ -25,6 +25,7 @@
 #include "access/table.h"
 #include "access/xact.h"
 #include "catalog/pg_constraint.h"
+#include "catalog/pg_inherits.h"
 #include "catalog/pg_proc.h"
 #include "catalog/pg_type.h"
 #include "executor/executor.h"
@@ -679,12 +680,14 @@ subquery_planner(PlannerGlobal *glob, Query *parse,
 		flatten_simple_union_all(root);
 
 	/*
-	 * Detect whether any rangetable entries are RTE_JOIN kind; if not, we can
-	 * avoid the expense of doing flatten_join_alias_vars().  Likewise check
-	 * whether any are RTE_RESULT kind; if not, we can skip
-	 * remove_useless_result_rtes().  Also check for outer joins --- if none,
-	 * we can skip reduce_outer_joins().  And check for LATERAL RTEs, too.
-	 * This must be done after we have done pull_up_subqueries(), of course.
+	 * Survey the rangetable to see what kinds of entries are present.  We can
+	 * skip some later processing if relevant SQL features are not used; for
+	 * example if there are no JOIN RTEs we can avoid the expense of doing
+	 * flatten_join_alias_vars().  This must be done after we have finished
+	 * adding rangetable entries, of course.  (Note: actually, processing of
+	 * inherited or partitioned rels can cause RTEs for their child tables to
+	 * get added later; but those must all be RTE_RELATION entries, so they
+	 * don't invalidate the conclusions drawn here.)
 	 */
 	root->hasJoinRTEs = false;
 	root->hasLateralRTEs = false;
@@ -694,38 +697,48 @@ subquery_planner(PlannerGlobal *glob, Query *parse,
 	{
 		RangeTblEntry *rte = lfirst_node(RangeTblEntry, l);
 
-		if (rte->rtekind == RTE_JOIN)
+		switch (rte->rtekind)
 		{
-			root->hasJoinRTEs = true;
-			if (IS_OUTER_JOIN(rte->jointype))
-				hasOuterJoins = true;
-		}
-		else if (rte->rtekind == RTE_RESULT)
-		{
-			hasResultRTEs = true;
+			case RTE_RELATION:
+				if (rte->inh)
+				{
+					/*
+					 * Check to see if the relation actually has any children;
+					 * if not, clear the inh flag so we can treat it as a
+					 * plain base relation.
+					 *
+					 * Note: this could give a false-positive result, if the
+					 * rel once had children but no longer does.  We used to
+					 * be able to clear rte->inh later on when we discovered
+					 * that, but no more; we have to handle such cases as
+					 * full-fledged inheritance.
+					 */
+					rte->inh = has_subclass(rte->relid);
+				}
+				break;
+			case RTE_JOIN:
+				root->hasJoinRTEs = true;
+				if (IS_OUTER_JOIN(rte->jointype))
+					hasOuterJoins = true;
+				break;
+			case RTE_RESULT:
+				hasResultRTEs = true;
+				break;
+			default:
+				/* No work here for other RTE types */
+				break;
 		}
+
 		if (rte->lateral)
 			root->hasLateralRTEs = true;
 	}
 
 	/*
 	 * Preprocess RowMark information.  We need to do this after subquery
-	 * pullup (so that all non-inherited RTEs are present) and before
-	 * inheritance expansion (so that the info is available for
-	 * expand_inherited_tables to examine and modify).
+	 * pullup, so that all base relations are present.
 	 */
 	preprocess_rowmarks(root);
 
-	/*
-	 * Expand any rangetable entries that are inheritance sets into "append
-	 * relations".  This can add entries to the rangetable, but they must be
-	 * plain RTE_RELATION entries, so it's OK (and marginally more efficient)
-	 * to do it after checking for joins and other special RTEs.  We must do
-	 * this after pulling up subqueries, else we'd fail to handle inherited
-	 * tables in subqueries.
-	 */
-	expand_inherited_tables(root);
-
 	/*
 	 * Set hasHavingQual to remember if HAVING clause is present.  Needed
 	 * because preprocess_expression will reduce a constant-true condition to
@@ -1180,11 +1193,17 @@ inheritance_planner(PlannerInfo *root)
 {
 	Query	   *parse = root->parse;
 	int			top_parentRTindex = parse->resultRelation;
+	List	   *select_rtable;
+	List	   *select_appinfos;
+	List	   *child_appinfos;
+	List	   *old_child_rtis;
+	List	   *new_child_rtis;
 	Bitmapset  *subqueryRTindexes;
-	Bitmapset  *modifiableARIindexes;
+	Index		next_subquery_rti;
 	int			nominalRelation = -1;
 	Index		rootRelation = 0;
 	List	   *final_rtable = NIL;
+	List	   *final_rowmarks = NIL;
 	int			save_rel_array_size = 0;
 	RelOptInfo **save_rel_array = NULL;
 	AppendRelInfo **save_append_rel_array = NULL;
@@ -1196,14 +1215,15 @@ inheritance_planner(PlannerInfo *root)
 	List	   *rowMarks;
 	RelOptInfo *final_rel;
 	ListCell   *lc;
+	ListCell   *lc2;
 	Index		rti;
 	RangeTblEntry *parent_rte;
-	PlannerInfo *parent_root;
-	Query	   *parent_parse;
-	Bitmapset  *parent_relids = bms_make_singleton(top_parentRTindex);
-	PlannerInfo **parent_roots = NULL;
+	Bitmapset  *parent_relids;
+	Query	  **parent_parses;
 
-	Assert(parse->commandType != CMD_INSERT);
+	/* Should only get here for UPDATE or DELETE */
+	Assert(parse->commandType == CMD_UPDATE ||
+		   parse->commandType == CMD_DELETE);
 
 	/*
 	 * We generate a modified instance of the original Query for each target
@@ -1233,32 +1253,6 @@ inheritance_planner(PlannerInfo *root)
 		rti++;
 	}
 
-	/*
-	 * Next, we want to identify which AppendRelInfo items contain references
-	 * to any of the aforesaid subquery RTEs.  These items will need to be
-	 * copied and modified to adjust their subquery references; whereas the
-	 * other ones need not be touched.  It's worth being tense over this
-	 * because we can usually avoid processing most of the AppendRelInfo
-	 * items, thereby saving O(N^2) space and time when the target is a large
-	 * inheritance tree.  We can identify AppendRelInfo items by their
-	 * child_relid, since that should be unique within the list.
-	 */
-	modifiableARIindexes = NULL;
-	if (subqueryRTindexes != NULL)
-	{
-		foreach(lc, root->append_rel_list)
-		{
-			AppendRelInfo *appinfo = lfirst_node(AppendRelInfo, lc);
-
-			if (bms_is_member(appinfo->parent_relid, subqueryRTindexes) ||
-				bms_is_member(appinfo->child_relid, subqueryRTindexes) ||
-				bms_overlap(pull_varnos((Node *) appinfo->translated_vars),
-							subqueryRTindexes))
-				modifiableARIindexes = bms_add_member(modifiableARIindexes,
-													  appinfo->child_relid);
-		}
-	}
-
 	/*
 	 * If the parent RTE is a partitioned table, we should use that as the
 	 * nominal target relation, because the RTEs added for partitioned tables
@@ -1266,7 +1260,8 @@ inheritance_planner(PlannerInfo *root)
 	 * not appear anywhere else in the plan, so the confusion explained below
 	 * for non-partitioning inheritance cases is not possible.
 	 */
-	parent_rte = rt_fetch(top_parentRTindex, root->parse->rtable);
+	parent_rte = rt_fetch(top_parentRTindex, parse->rtable);
+	Assert(parent_rte->inh);
 	if (parent_rte->relkind == RELKIND_PARTITIONED_TABLE)
 	{
 		nominalRelation = top_parentRTindex;
@@ -1274,48 +1269,218 @@ inheritance_planner(PlannerInfo *root)
 	}
 
 	/*
-	 * The PlannerInfo for each child is obtained by translating the relevant
-	 * members of the PlannerInfo for its immediate parent, which we find
-	 * using the parent_relid in its AppendRelInfo.  We save the PlannerInfo
-	 * for each parent in an array indexed by relid for fast retrieval. Since
-	 * the maximum number of parents is limited by the number of RTEs in the
-	 * query, we use that number to allocate the array. An extra entry is
-	 * needed since relids start from 1.
+	 * Before generating the real per-child-relation plans, do a cycle of
+	 * planning as though the query were a SELECT.  The objective here is to
+	 * find out which child relations need to be processed, using the same
+	 * expansion and pruning logic as for a SELECT.  We'll then pull out the
+	 * RangeTblEntry-s generated for the child rels, and make use of the
+	 * AppendRelInfo entries for them to guide the real planning.  (This is
+	 * rather inefficient; we could perhaps stop short of making a full Path
+	 * tree.  But this whole function is inefficient and slated for
+	 * destruction, so let's not contort query_planner for that.)
+	 */
+	{
+		PlannerInfo *subroot;
+
+		/*
+		 * Flat-copy the PlannerInfo to prevent modification of the original.
+		 */
+		subroot = makeNode(PlannerInfo);
+		memcpy(subroot, root, sizeof(PlannerInfo));
+
+		/*
+		 * Make a deep copy of the parsetree for this planning cycle to mess
+		 * around with, and change it to look like a SELECT.  (Hack alert: the
+		 * target RTE still has updatedCols set if this is an UPDATE, so that
+		 * expand_partitioned_rtentry will correctly update
+		 * subroot->partColsUpdated.)
+		 */
+		subroot->parse = copyObject(root->parse);
+
+		subroot->parse->commandType = CMD_SELECT;
+		subroot->parse->resultRelation = 0;
+
+		/*
+		 * Ensure the subroot has its own copy of the original
+		 * append_rel_list, since it'll be scribbled on.  (Note that at this
+		 * point, the list only contains AppendRelInfos for flattened UNION
+		 * ALL subqueries.)
+		 */
+		subroot->append_rel_list = copyObject(root->append_rel_list);
+
+		/*
+		 * Better make a private copy of the rowMarks, too.
+		 */
+		subroot->rowMarks = copyObject(root->rowMarks);
+
+		/* There shouldn't be any OJ info to translate, as yet */
+		Assert(subroot->join_info_list == NIL);
+		/* and we haven't created PlaceHolderInfos, either */
+		Assert(subroot->placeholder_list == NIL);
+
+		/* Generate Path(s) for accessing this result relation */
+		grouping_planner(subroot, true, 0.0 /* retrieve all tuples */ );
+
+		/* Extract the info we need. */
+		select_rtable = subroot->parse->rtable;
+		select_appinfos = subroot->append_rel_list;
+
+		/*
+		 * We need to propagate partColsUpdated back, too.  (The later
+		 * planning cycles will not set this because they won't run
+		 * expand_partitioned_rtentry for the UPDATE target.)
+		 */
+		root->partColsUpdated = subroot->partColsUpdated;
+	}
+
+	/*----------
+	 * Since only one rangetable can exist in the final plan, we need to make
+	 * sure that it contains all the RTEs needed for any child plan.  This is
+	 * complicated by the need to use separate subquery RTEs for each child.
+	 * We arrange the final rtable as follows:
+	 * 1. All original rtable entries (with their original RT indexes).
+	 * 2. All the relation RTEs generated for children of the target table.
+	 * 3. Subquery RTEs for children after the first.  We need N * (K - 1)
+	 *    RT slots for this, if there are N subqueries and K child tables.
+	 * 4. Additional RTEs generated during the child planning runs, such as
+	 *    children of inheritable RTEs other than the target table.
+	 * We assume that each child planning run will create an identical set
+	 * of type-4 RTEs.
+	 *
+	 * So the next thing to do is append the type-2 RTEs (the target table's
+	 * children) to the original rtable.  We look through select_appinfos
+	 * to find them.
+	 *
+	 * To identify which AppendRelInfos are relevant as we thumb through
+	 * select_appinfos, we need to look for both direct and indirect children
+	 * of top_parentRTindex, so we use a bitmap of known parent relids.
+	 * expand_inherited_rtentry() always processes a parent before any of that
+	 * parent's children, so we should see an intermediate parent before its
+	 * children.
+	 *----------
+	 */
+	child_appinfos = NIL;
+	old_child_rtis = NIL;
+	new_child_rtis = NIL;
+	parent_relids = bms_make_singleton(top_parentRTindex);
+	foreach(lc, select_appinfos)
+	{
+		AppendRelInfo *appinfo = lfirst_node(AppendRelInfo, lc);
+		RangeTblEntry *child_rte;
+
+		/* append_rel_list contains all append rels; ignore others */
+		if (!bms_is_member(appinfo->parent_relid, parent_relids))
+			continue;
+
+		/* remember relevant AppendRelInfos for use below */
+		child_appinfos = lappend(child_appinfos, appinfo);
+
+		/* extract RTE for this child rel */
+		child_rte = rt_fetch(appinfo->child_relid, select_rtable);
+
+		/* and append it to the original rtable */
+		parse->rtable = lappend(parse->rtable, child_rte);
+
+		/* remember child's index in the SELECT rtable */
+		old_child_rtis = lappend_int(old_child_rtis, appinfo->child_relid);
+
+		/* and its new index in the final rtable */
+		new_child_rtis = lappend_int(new_child_rtis, list_length(parse->rtable));
+
+		/* if child is itself partitioned, update parent_relids */
+		if (child_rte->inh)
+		{
+			Assert(child_rte->relkind == RELKIND_PARTITIONED_TABLE);
+			parent_relids = bms_add_member(parent_relids, appinfo->child_relid);
+		}
+	}
+
+	/*
+	 * It's possible that the RTIs we just assigned for the child rels in the
+	 * final rtable are different from what they were in the SELECT query.
+	 * Adjust the AppendRelInfos so that they will correctly map RT indexes to
+	 * the final indexes.  We can do this left-to-right since no child rel's
+	 * final RT index could be greater than what it had in the SELECT query.
+	 */
+	forboth(lc, old_child_rtis, lc2, new_child_rtis)
+	{
+		int			old_child_rti = lfirst_int(lc);
+		int			new_child_rti = lfirst_int(lc2);
+
+		if (old_child_rti == new_child_rti)
+			continue;			/* nothing to do */
+
+		Assert(old_child_rti > new_child_rti);
+
+		ChangeVarNodes((Node *) child_appinfos,
+					   old_child_rti, new_child_rti, 0);
+	}
+
+	/*
+	 * Now set up rangetable entries for subqueries for additional children
+	 * (the first child will just use the original ones).  These all have to
+	 * look more or less real, or EXPLAIN will get unhappy; so we just make
+	 * them all clones of the original subqueries.
+	 */
+	next_subquery_rti = list_length(parse->rtable) + 1;
+	if (subqueryRTindexes != NULL)
+	{
+		int			n_children = list_length(child_appinfos);
+
+		while (n_children-- > 1)
+		{
+			int			oldrti = -1;
+
+			while ((oldrti = bms_next_member(subqueryRTindexes, oldrti)) >= 0)
+			{
+				RangeTblEntry *subqrte;
+
+				subqrte = rt_fetch(oldrti, parse->rtable);
+				parse->rtable = lappend(parse->rtable, copyObject(subqrte));
+			}
+		}
+	}
+
+	/*
+	 * The query for each child is obtained by translating the query for its
+	 * immediate parent, since the AppendRelInfo data we have shows deltas
+	 * between parents and children.  We use the parent_parses array to
+	 * remember the appropriate query trees.  This is indexed by parent relid.
+	 * Since the maximum number of parents is limited by the number of RTEs in
+	 * the SELECT query, we use that number to allocate the array.  An extra
+	 * entry is needed since relids start from 1.
 	 */
-	parent_roots = (PlannerInfo **) palloc0((list_length(parse->rtable) + 1) *
-											sizeof(PlannerInfo *));
-	parent_roots[top_parentRTindex] = root;
+	parent_parses = (Query **) palloc0((list_length(select_rtable) + 1) *
+									   sizeof(Query *));
+	parent_parses[top_parentRTindex] = parse;
 
 	/*
 	 * And now we can get on with generating a plan for each child table.
 	 */
-	foreach(lc, root->append_rel_list)
+	foreach(lc, child_appinfos)
 	{
 		AppendRelInfo *appinfo = lfirst_node(AppendRelInfo, lc);
+		Index		this_subquery_rti = next_subquery_rti;
+		Query	   *parent_parse;
 		PlannerInfo *subroot;
 		RangeTblEntry *child_rte;
 		RelOptInfo *sub_final_rel;
 		Path	   *subpath;
 
-		/* append_rel_list contains all append rels; ignore others */
-		if (!bms_is_member(appinfo->parent_relid, parent_relids))
-			continue;
-
 		/*
 		 * expand_inherited_rtentry() always processes a parent before any of
-		 * that parent's children, so the parent_root for this relation should
-		 * already be available.
+		 * that parent's children, so the parent query for this relation
+		 * should already be available.
 		 */
-		parent_root = parent_roots[appinfo->parent_relid];
-		Assert(parent_root != NULL);
-		parent_parse = parent_root->parse;
+		parent_parse = parent_parses[appinfo->parent_relid];
+		Assert(parent_parse != NULL);
 
 		/*
 		 * We need a working copy of the PlannerInfo so that we can control
 		 * propagation of information back to the main copy.
 		 */
 		subroot = makeNode(PlannerInfo);
-		memcpy(subroot, parent_root, sizeof(PlannerInfo));
+		memcpy(subroot, root, sizeof(PlannerInfo));
 
 		/*
 		 * Generate modified query with this rel as target.  We first apply
@@ -1324,7 +1489,7 @@ inheritance_planner(PlannerInfo *root)
 		 * then fool around with subquery RTEs.
 		 */
 		subroot->parse = (Query *)
-			adjust_appendrel_attrs(parent_root,
+			adjust_appendrel_attrs(subroot,
 								   (Node *) parent_parse,
 								   1, &appinfo);
 
@@ -1360,9 +1525,7 @@ inheritance_planner(PlannerInfo *root)
 		if (child_rte->inh)
 		{
 			Assert(child_rte->relkind == RELKIND_PARTITIONED_TABLE);
-			parent_relids = bms_add_member(parent_relids, appinfo->child_relid);
-			parent_roots[appinfo->child_relid] = subroot;
-
+			parent_parses[appinfo->child_relid] = subroot->parse;
 			continue;
 		}
 
@@ -1383,108 +1546,38 @@ inheritance_planner(PlannerInfo *root)
 		 * is used elsewhere in the plan, so using the original parent RTE
 		 * would give rise to confusing use of multiple aliases in EXPLAIN
 		 * output for what the user will think is the "same" table.  OTOH,
-		 * it's not a problem in the partitioned inheritance case, because the
-		 * duplicate child RTE added for the parent does not appear anywhere
-		 * else in the plan tree.
+		 * it's not a problem in the partitioned inheritance case, because
+		 * there is no duplicate RTE for the parent.
 		 */
 		if (nominalRelation < 0)
 			nominalRelation = appinfo->child_relid;
 
 		/*
-		 * The rowMarks list might contain references to subquery RTEs, so
-		 * make a copy that we can apply ChangeVarNodes to.  (Fortunately, the
-		 * executor doesn't need to see the modified copies --- we can just
-		 * pass it the original rowMarks list.)
-		 */
-		subroot->rowMarks = copyObject(parent_root->rowMarks);
-
-		/*
-		 * The append_rel_list likewise might contain references to subquery
-		 * RTEs (if any subqueries were flattenable UNION ALLs).  So prepare
-		 * to apply ChangeVarNodes to that, too.  As explained above, we only
-		 * want to copy items that actually contain such references; the rest
-		 * can just get linked into the subroot's append_rel_list.
-		 *
-		 * If we know there are no such references, we can just use the outer
-		 * append_rel_list unmodified.
-		 */
-		if (modifiableARIindexes != NULL)
-		{
-			ListCell   *lc2;
-
-			subroot->append_rel_list = NIL;
-			foreach(lc2, parent_root->append_rel_list)
-			{
-				AppendRelInfo *appinfo2 = lfirst_node(AppendRelInfo, lc2);
-
-				if (bms_is_member(appinfo2->child_relid, modifiableARIindexes))
-					appinfo2 = copyObject(appinfo2);
-
-				subroot->append_rel_list = lappend(subroot->append_rel_list,
-												   appinfo2);
-			}
-		}
-
-		/*
-		 * Add placeholders to the child Query's rangetable list to fill the
-		 * RT indexes already reserved for subqueries in previous children.
-		 * These won't be referenced, so there's no need to make them very
-		 * valid-looking.
+		 * As above, each child plan run needs its own append_rel_list and
+		 * rowmarks, which should start out as pristine copies of the
+		 * originals.  There can't be any references to UPDATE/DELETE target
+		 * rels in them; but there could be subquery references, which we'll
+		 * fix up in a moment.
 		 */
-		while (list_length(subroot->parse->rtable) < list_length(final_rtable))
-			subroot->parse->rtable = lappend(subroot->parse->rtable,
-											 makeNode(RangeTblEntry));
+		subroot->append_rel_list = copyObject(root->append_rel_list);
+		subroot->rowMarks = copyObject(root->rowMarks);
 
 		/*
-		 * If this isn't the first child Query, generate duplicates of all
-		 * subquery RTEs, and adjust Var numbering to reference the
-		 * duplicates. To simplify the loop logic, we scan the original rtable
-		 * not the copy just made by adjust_appendrel_attrs; that should be OK
-		 * since subquery RTEs couldn't contain any references to the target
-		 * rel.
+		 * If this isn't the first child Query, adjust Vars and jointree
+		 * entries to reference the appropriate set of subquery RTEs.
 		 */
 		if (final_rtable != NIL && subqueryRTindexes != NULL)
 		{
-			ListCell   *lr;
+			int			oldrti = -1;
 
-			rti = 1;
-			foreach(lr, parent_parse->rtable)
+			while ((oldrti = bms_next_member(subqueryRTindexes, oldrti)) >= 0)
 			{
-				RangeTblEntry *rte = lfirst_node(RangeTblEntry, lr);
-
-				if (bms_is_member(rti, subqueryRTindexes))
-				{
-					Index		newrti;
-
-					/*
-					 * The RTE can't contain any references to its own RT
-					 * index, except in its securityQuals, so we can save a
-					 * few cycles by applying ChangeVarNodes to the rest of
-					 * the rangetable before we append the RTE to it.
-					 */
-					newrti = list_length(subroot->parse->rtable) + 1;
-					ChangeVarNodes((Node *) subroot->parse, rti, newrti, 0);
-					ChangeVarNodes((Node *) subroot->rowMarks, rti, newrti, 0);
-					/* Skip processing unchanging parts of append_rel_list */
-					if (modifiableARIindexes != NULL)
-					{
-						ListCell   *lc2;
-
-						foreach(lc2, subroot->append_rel_list)
-						{
-							AppendRelInfo *appinfo2 = lfirst_node(AppendRelInfo, lc2);
+				Index		newrti = next_subquery_rti++;
 
-							if (bms_is_member(appinfo2->child_relid,
-											  modifiableARIindexes))
-								ChangeVarNodes((Node *) appinfo2, rti, newrti, 0);
-						}
-					}
-					rte = copyObject(rte);
-					ChangeVarNodes((Node *) rte->securityQuals, rti, newrti, 0);
-					subroot->parse->rtable = lappend(subroot->parse->rtable,
-													 rte);
-				}
-				rti++;
+				ChangeVarNodes((Node *) subroot->parse, oldrti, newrti, 0);
+				ChangeVarNodes((Node *) subroot->append_rel_list,
+							   oldrti, newrti, 0);
+				ChangeVarNodes((Node *) subroot->rowMarks, oldrti, newrti, 0);
 			}
 		}
 
@@ -1514,22 +1607,43 @@ inheritance_planner(PlannerInfo *root)
 
 		/*
 		 * If this is the first non-excluded child, its post-planning rtable
-		 * becomes the initial contents of final_rtable; otherwise, append
-		 * just its modified subquery RTEs to final_rtable.
+		 * becomes the initial contents of final_rtable; otherwise, copy its
+		 * modified subquery RTEs into final_rtable, to ensure we have sane
+		 * copies of those.  Also save the first non-excluded child's version
+		 * of the rowmarks list; we assume all children will end up with
+		 * equivalent versions of that.
 		 */
 		if (final_rtable == NIL)
+		{
 			final_rtable = subroot->parse->rtable;
+			final_rowmarks = subroot->rowMarks;
+		}
 		else
-			final_rtable = list_concat(final_rtable,
-									   list_copy_tail(subroot->parse->rtable,
-													  list_length(final_rtable)));
+		{
+			Assert(list_length(final_rtable) ==
+				   list_length(subroot->parse->rtable));
+			if (subqueryRTindexes != NULL)
+			{
+				int			oldrti = -1;
+
+				while ((oldrti = bms_next_member(subqueryRTindexes, oldrti)) >= 0)
+				{
+					Index		newrti = this_subquery_rti++;
+					RangeTblEntry *subqrte;
+					ListCell   *newrticell;
+
+					subqrte = rt_fetch(newrti, subroot->parse->rtable);
+					newrticell = list_nth_cell(final_rtable, newrti - 1);
+					lfirst(newrticell) = subqrte;
+				}
+			}
+		}
 
 		/*
 		 * We need to collect all the RelOptInfos from all child plans into
 		 * the main PlannerInfo, since setrefs.c will need them.  We use the
-		 * last child's simple_rel_array (previous ones are too short), so we
-		 * have to propagate forward the RelOptInfos that were already built
-		 * in previous children.
+		 * last child's simple_rel_array, so we have to propagate forward the
+		 * RelOptInfos that were already built in previous children.
 		 */
 		Assert(subroot->simple_rel_array_size >= save_rel_array_size);
 		for (rti = 1; rti < save_rel_array_size; rti++)
@@ -1543,7 +1657,11 @@ inheritance_planner(PlannerInfo *root)
 		save_rel_array = subroot->simple_rel_array;
 		save_append_rel_array = subroot->append_rel_array;
 
-		/* Make sure any initplans from this rel get into the outer list */
+		/*
+		 * Make sure any initplans from this rel get into the outer list. Note
+		 * we're effectively assuming all children generate the same
+		 * init_plans.
+		 */
 		root->init_plans = subroot->init_plans;
 
 		/* Build list of sub-paths */
@@ -1626,6 +1744,9 @@ inheritance_planner(PlannerInfo *root)
 
 			root->simple_rte_array[rti++] = rte;
 		}
+
+		/* Put back adjusted rowmarks, too */
+		root->rowMarks = final_rowmarks;
 	}
 
 	/*
@@ -6127,9 +6248,10 @@ plan_create_index_workers(Oid tableOid, Oid indexOid)
 	/*
 	 * Build a minimal RTE.
 	 *
-	 * Set the target's table to be an inheritance parent.  This is a kludge
-	 * that prevents problems within get_relation_info(), which does not
-	 * expect that any IndexOptInfo is currently undergoing REINDEX.
+	 * Mark the RTE with inh = true.  This is a kludge to prevent
+	 * get_relation_info() from fetching index info, which is necessary
+	 * because it does not expect that any IndexOptInfo is currently
+	 * undergoing REINDEX.
 	 */
 	rte = makeNode(RangeTblEntry);
 	rte->rtekind = RTE_RELATION;

src/backend/optimizer/prep/preptlist.c

@@ -121,7 +121,9 @@ preprocess_targetlist(PlannerInfo *root)
 	/*
 	 * Add necessary junk columns for rowmarked rels.  These values are needed
 	 * for locking of rels selected FOR UPDATE/SHARE, and to do EvalPlanQual
-	 * rechecking.  See comments for PlanRowMark in plannodes.h.
+	 * rechecking.  See comments for PlanRowMark in plannodes.h.  If you
+	 * change this stanza, see also expand_inherited_rtentry(), which has to
+	 * be able to add on junk columns equivalent to these.
 	 */
 	foreach(lc, root->rowMarks)
 	{

src/backend/optimizer/util/inherit.c

@@ -18,110 +18,90 @@
 #include "access/table.h"
 #include "catalog/partition.h"
 #include "catalog/pg_inherits.h"
+#include "catalog/pg_type.h"
 #include "miscadmin.h"
+#include "nodes/makefuncs.h"
 #include "optimizer/appendinfo.h"
 #include "optimizer/inherit.h"
+#include "optimizer/optimizer.h"
+#include "optimizer/pathnode.h"
+#include "optimizer/planmain.h"
 #include "optimizer/planner.h"
 #include "optimizer/prep.h"
+#include "optimizer/restrictinfo.h"
+#include "parser/parsetree.h"
 #include "partitioning/partdesc.h"
+#include "partitioning/partprune.h"
 #include "utils/rel.h"
 
 
-static void expand_inherited_rtentry(PlannerInfo *root, RangeTblEntry *rte,
-						 Index rti);
-static void expand_partitioned_rtentry(PlannerInfo *root,
+static void expand_partitioned_rtentry(PlannerInfo *root, RelOptInfo *relinfo,
 						   RangeTblEntry *parentrte,
 						   Index parentRTindex, Relation parentrel,
-						   PlanRowMark *top_parentrc, LOCKMODE lockmode,
-						   List **appinfos);
+						   PlanRowMark *top_parentrc, LOCKMODE lockmode);
 static void expand_single_inheritance_child(PlannerInfo *root,
 								RangeTblEntry *parentrte,
 								Index parentRTindex, Relation parentrel,
 								PlanRowMark *top_parentrc, Relation childrel,
-								List **appinfos, RangeTblEntry **childrte_p,
+								RangeTblEntry **childrte_p,
 								Index *childRTindex_p);
 static Bitmapset *translate_col_privs(const Bitmapset *parent_privs,
 					List *translated_vars);
+static void expand_appendrel_subquery(PlannerInfo *root, RelOptInfo *rel,
+						  RangeTblEntry *rte, Index rti);
 
 
-/*
- * expand_inherited_tables
- *		Expand each rangetable entry that represents an inheritance set
- *		into an "append relation".  At the conclusion of this process,
- *		the "inh" flag is set in all and only those RTEs that are append
- *		relation parents.
- */
-void
-expand_inherited_tables(PlannerInfo *root)
-{
-	Index		nrtes;
-	Index		rti;
-	ListCell   *rl;
-
-	/*
-	 * expand_inherited_rtentry may add RTEs to parse->rtable. The function is
-	 * expected to recursively handle any RTEs that it creates with inh=true.
-	 * So just scan as far as the original end of the rtable list.
-	 */
-	nrtes = list_length(root->parse->rtable);
-	rl = list_head(root->parse->rtable);
-	for (rti = 1; rti <= nrtes; rti++)
-	{
-		RangeTblEntry *rte = (RangeTblEntry *) lfirst(rl);
-
-		expand_inherited_rtentry(root, rte, rti);
-		rl = lnext(rl);
-	}
-}
-
 /*
  * expand_inherited_rtentry
- *		Check whether a rangetable entry represents an inheritance set.
- *		If so, add entries for all the child tables to the query's
- *		rangetable, and build AppendRelInfo nodes for all the child tables
- *		and add them to root->append_rel_list.  If not, clear the entry's
- *		"inh" flag to prevent later code from looking for AppendRelInfos.
+ *		Expand a rangetable entry that has the "inh" bit set.
+ *
+ * "inh" is only allowed in two cases: RELATION and SUBQUERY RTEs.
  *
- * Note that the original RTE is considered to represent the whole
- * inheritance set.  The first of the generated RTEs is an RTE for the same
- * table, but with inh = false, to represent the parent table in its role
- * as a simple member of the inheritance set.
+ * "inh" on a plain RELATION RTE means that it is a partitioned table or the
+ * parent of a traditional-inheritance set.  In this case we must add entries
+ * for all the interesting child tables to the query's rangetable, and build
+ * additional planner data structures for them, including RelOptInfos,
+ * AppendRelInfos, and possibly PlanRowMarks.
  *
- * A childless table is never considered to be an inheritance set. For
- * regular inheritance, a parent RTE must always have at least two associated
- * AppendRelInfos: one corresponding to the parent table as a simple member of
- * the inheritance set and one or more corresponding to the actual children.
- * (But a partitioned table might have only one associated AppendRelInfo,
- * since it's not itself scanned and hence doesn't need a second RTE to
- * represent itself as a member of the set.)
+ * Note that the original RTE is considered to represent the whole inheritance
+ * set.  In the case of traditional inheritance, the first of the generated
+ * RTEs is an RTE for the same table, but with inh = false, to represent the
+ * parent table in its role as a simple member of the inheritance set.  For
+ * partitioning, we don't need a second RTE because the partitioned table
+ * itself has no data and need not be scanned.
+ *
+ * "inh" on a SUBQUERY RTE means that it's the parent of a UNION ALL group,
+ * which is treated as an appendrel similarly to inheritance cases; however,
+ * we already made RTEs and AppendRelInfos for the subqueries.  We only need
+ * to build RelOptInfos for them, which is done by expand_appendrel_subquery.
  */
-static void
-expand_inherited_rtentry(PlannerInfo *root, RangeTblEntry *rte, Index rti)
+void
+expand_inherited_rtentry(PlannerInfo *root, RelOptInfo *rel,
+						 RangeTblEntry *rte, Index rti)
 {
 	Oid			parentOID;
-	PlanRowMark *oldrc;
 	Relation	oldrelation;
 	LOCKMODE	lockmode;
-	List	   *inhOIDs;
-	ListCell   *l;
+	PlanRowMark *oldrc;
+	bool		old_isParent = false;
+	int			old_allMarkTypes = 0;
 
-	/* Does RT entry allow inheritance? */
-	if (!rte->inh)
-		return;
-	/* Ignore any already-expanded UNION ALL nodes */
-	if (rte->rtekind != RTE_RELATION)
+	Assert(rte->inh);			/* else caller error */
+
+	if (rte->rtekind == RTE_SUBQUERY)
 	{
-		Assert(rte->rtekind == RTE_SUBQUERY);
+		expand_appendrel_subquery(root, rel, rte, rti);
 		return;
 	}
-	/* Fast path for common case of childless table */
+
+	Assert(rte->rtekind == RTE_RELATION);
+
 	parentOID = rte->relid;
-	if (!has_subclass(parentOID))
-	{
-		/* Clear flag before returning */
-		rte->inh = false;
-		return;
-	}
+
+	/*
+	 * We used to check has_subclass() here, but there's no longer any need
+	 * to, because subquery_planner already did.
+	 */
 
 	/*
 	 * The rewriter should already have obtained an appropriate lock on each
@@ -141,7 +121,12 @@ expand_inherited_rtentry(PlannerInfo *root, RangeTblEntry *rte, Index rti)
 	 */
 	oldrc = get_plan_rowmark(root->rowMarks, rti);
 	if (oldrc)
+	{
+		old_isParent = oldrc->isParent;
 		oldrc->isParent = true;
+		/* Save initial value of allMarkTypes before children add to it */
+		old_allMarkTypes = oldrc->allMarkTypes;
+	}
 
 	/* Scan the inheritance set and expand it */
 	if (oldrelation->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
@@ -151,17 +136,12 @@ expand_inherited_rtentry(PlannerInfo *root, RangeTblEntry *rte, Index rti)
 		 */
 		Assert(rte->relkind == RELKIND_PARTITIONED_TABLE);
 
-		if (root->glob->partition_directory == NULL)
-			root->glob->partition_directory =
-				CreatePartitionDirectory(CurrentMemoryContext);
-
 		/*
-		 * If this table has partitions, recursively expand and lock them.
-		 * While at it, also extract the partition key columns of all the
-		 * partitioned tables.
+		 * Recursively expand and lock the partitions.  While at it, also
+		 * extract the partition key columns of all the partitioned tables.
 		 */
-		expand_partitioned_rtentry(root, rte, rti, oldrelation, oldrc,
-								   lockmode, &root->append_rel_list);
+		expand_partitioned_rtentry(root, rel, rte, rti,
+								   oldrelation, oldrc, lockmode);
 	}
 	else
 	{
@@ -170,25 +150,25 @@ expand_inherited_rtentry(PlannerInfo *root, RangeTblEntry *rte, Index rti)
 		 * that partitioned tables are not allowed to have inheritance
 		 * children, so it's not possible for both cases to apply.)
 		 */
-		List	   *appinfos = NIL;
-		RangeTblEntry *childrte;
-		Index		childRTindex;
+		List	   *inhOIDs;
+		ListCell   *l;
 
 		/* Scan for all members of inheritance set, acquire needed locks */
 		inhOIDs = find_all_inheritors(parentOID, lockmode, NULL);
 
 		/*
-		 * Check that there's at least one descendant, else treat as no-child
-		 * case.  This could happen despite above has_subclass() check, if the
-		 * table once had a child but no longer does.
+		 * We used to special-case the situation where the table no longer has
+		 * any children, by clearing rte->inh and exiting.  That no longer
+		 * works, because this function doesn't get run until after decisions
+		 * have been made that depend on rte->inh.  We have to treat such
+		 * situations as normal inheritance.  The table itself should always
+		 * have been found, though.
 		 */
-		if (list_length(inhOIDs) < 2)
-		{
-			/* Clear flag before returning */
-			rte->inh = false;
-			heap_close(oldrelation, NoLock);
-			return;
-		}
+		Assert(inhOIDs != NIL);
+		Assert(linitial_oid(inhOIDs) == parentOID);
+
+		/* Expand simple_rel_array and friends to hold child objects. */
+		expand_planner_arrays(root, list_length(inhOIDs));
 
 		/*
 		 * Expand inheritance children in the order the OIDs were returned by
@@ -198,6 +178,8 @@ expand_inherited_rtentry(PlannerInfo *root, RangeTblEntry *rte, Index rti)
 		{
 			Oid			childOID = lfirst_oid(l);
 			Relation	newrelation;
+			RangeTblEntry *childrte;
+			Index		childRTindex;
 
 			/* Open rel if needed; we already have required locks */
 			if (childOID != parentOID)
@@ -217,29 +199,78 @@ expand_inherited_rtentry(PlannerInfo *root, RangeTblEntry *rte, Index rti)
 				continue;
 			}
 
-			expand_single_inheritance_child(root, rte, rti, oldrelation, oldrc,
-											newrelation,
-											&appinfos, &childrte,
-											&childRTindex);
+			/* Create RTE and AppendRelInfo, plus PlanRowMark if needed. */
+			expand_single_inheritance_child(root, rte, rti, oldrelation,
+											oldrc, newrelation,
+											&childrte, &childRTindex);
+
+			/* Create the otherrel RelOptInfo too. */
+			(void) build_simple_rel(root, childRTindex, rel);
 
 			/* Close child relations, but keep locks */
 			if (childOID != parentOID)
 				table_close(newrelation, NoLock);
 		}
+	}
+
+	/*
+	 * Some children might require different mark types, which would've been
+	 * reported into oldrc.  If so, add relevant entries to the top-level
+	 * targetlist and update parent rel's reltarget.  This should match what
+	 * preprocess_targetlist() would have added if the mark types had been
+	 * requested originally.
+	 */
+	if (oldrc)
+	{
+		int			new_allMarkTypes = oldrc->allMarkTypes;
+		Var		   *var;
+		TargetEntry *tle;
+		char		resname[32];
+		List	   *newvars = NIL;
+
+		/* The old PlanRowMark should already have necessitated adding TID */
+		Assert(old_allMarkTypes & ~(1 << ROW_MARK_COPY));
+
+		/* Add whole-row junk Var if needed, unless we had it already */
+		if ((new_allMarkTypes & (1 << ROW_MARK_COPY)) &&
+			!(old_allMarkTypes & (1 << ROW_MARK_COPY)))
+		{
+			var = makeWholeRowVar(planner_rt_fetch(oldrc->rti, root),
+								  oldrc->rti,
+								  0,
+								  false);
+			snprintf(resname, sizeof(resname), "wholerow%u", oldrc->rowmarkId);
+			tle = makeTargetEntry((Expr *) var,
+								  list_length(root->processed_tlist) + 1,
+								  pstrdup(resname),
+								  true);
+			root->processed_tlist = lappend(root->processed_tlist, tle);
+			newvars = lappend(newvars, var);
+		}
+
+		/* Add tableoid junk Var, unless we had it already */
+		if (!old_isParent)
+		{
+			var = makeVar(oldrc->rti,
+						  TableOidAttributeNumber,
+						  OIDOID,
+						  -1,
+						  InvalidOid,
+						  0);
+			snprintf(resname, sizeof(resname), "tableoid%u", oldrc->rowmarkId);
+			tle = makeTargetEntry((Expr *) var,
+								  list_length(root->processed_tlist) + 1,
+								  pstrdup(resname),
+								  true);
+			root->processed_tlist = lappend(root->processed_tlist, tle);
+			newvars = lappend(newvars, var);
+		}
 
 		/*
-		 * If all the children were temp tables, pretend it's a
-		 * non-inheritance situation; we don't need Append node in that case.
-		 * The duplicate RTE we added for the parent table is harmless, so we
-		 * don't bother to get rid of it; ditto for the useless PlanRowMark
-		 * node.
+		 * Add the newly added Vars to parent's reltarget.  We needn't worry
+		 * about the children's reltargets, they'll be made later.
 		 */
-		if (list_length(appinfos) < 2)
-			rte->inh = false;
-		else
-			root->append_rel_list = list_concat(root->append_rel_list,
-												appinfos);
-
+		add_vars_to_targetlist(root, newvars, bms_make_singleton(0), false);
 	}
 
 	table_close(oldrelation, NoLock);
@@ -250,26 +281,26 @@ expand_inherited_rtentry(PlannerInfo *root, RangeTblEntry *rte, Index rti)
  *		Recursively expand an RTE for a partitioned table.
  */
 static void
-expand_partitioned_rtentry(PlannerInfo *root, RangeTblEntry *parentrte,
+expand_partitioned_rtentry(PlannerInfo *root, RelOptInfo *relinfo,
+						   RangeTblEntry *parentrte,
 						   Index parentRTindex, Relation parentrel,
-						   PlanRowMark *top_parentrc, LOCKMODE lockmode,
-						   List **appinfos)
+						   PlanRowMark *top_parentrc, LOCKMODE lockmode)
 {
-	int			i;
-	RangeTblEntry *childrte;
-	Index		childRTindex;
 	PartitionDesc partdesc;
+	Bitmapset  *live_parts;
+	int			num_live_parts;
+	int			i;
+
+	check_stack_depth();
+
+	Assert(parentrte->inh);
 
 	partdesc = PartitionDirectoryLookup(root->glob->partition_directory,
 										parentrel);
 
-	check_stack_depth();
-
 	/* A partitioned table should always have a partition descriptor. */
 	Assert(partdesc);
 
-	Assert(parentrte->inh);
-
 	/*
 	 * Note down whether any partition key cols are being updated. Though it's
 	 * the root partitioned table's updatedCols we are interested in, we
@@ -285,25 +316,45 @@ expand_partitioned_rtentry(PlannerInfo *root, RangeTblEntry *parentrte,
 	 */
 	Assert(!has_partition_attrs(parentrel, parentrte->extraUpdatedCols, NULL));
 
-	/*
-	 * If the partitioned table has no partitions, treat this as the
-	 * non-inheritance case.
-	 */
+	/* Nothing further to do here if there are no partitions. */
 	if (partdesc->nparts == 0)
-	{
-		parentrte->inh = false;
 		return;
-	}
 
 	/*
-	 * Create a child RTE for each partition.  Note that unlike traditional
-	 * inheritance, we don't need a child RTE for the partitioned table
-	 * itself, because it's not going to be scanned.
+	 * Perform partition pruning using restriction clauses assigned to parent
+	 * relation.  live_parts will contain PartitionDesc indexes of partitions
+	 * that survive pruning.  Below, we will initialize child objects for the
+	 * surviving partitions.
 	 */
-	for (i = 0; i < partdesc->nparts; i++)
+	live_parts = prune_append_rel_partitions(relinfo);
+
+	/* Expand simple_rel_array and friends to hold child objects. */
+	num_live_parts = bms_num_members(live_parts);
+	if (num_live_parts > 0)
+		expand_planner_arrays(root, num_live_parts);
+
+	/*
+	 * We also store partition RelOptInfo pointers in the parent relation.
+	 * Since we're palloc0'ing, slots corresponding to pruned partitions will
+	 * contain NULL.
+	 */
+	Assert(relinfo->part_rels == NULL);
+	relinfo->part_rels = (RelOptInfo **)
+		palloc0(relinfo->nparts * sizeof(RelOptInfo *));
+
+	/*
+	 * Create a child RTE for each live partition.  Note that unlike
+	 * traditional inheritance, we don't need a child RTE for the partitioned
+	 * table itself, because it's not going to be scanned.
+	 */
+	i = -1;
+	while ((i = bms_next_member(live_parts, i)) >= 0)
 	{
 		Oid			childOID = partdesc->oids[i];
 		Relation	childrel;
+		RangeTblEntry *childrte;
+		Index		childRTindex;
+		RelOptInfo *childrelinfo;
 
 		/* Open rel, acquiring required locks */
 		childrel = table_open(childOID, lockmode);
@@ -316,15 +367,20 @@ expand_partitioned_rtentry(PlannerInfo *root, RangeTblEntry *parentrte,
 		if (RELATION_IS_OTHER_TEMP(childrel))
 			elog(ERROR, "temporary relation from another session found as partition");
 
+		/* Create RTE and AppendRelInfo, plus PlanRowMark if needed. */
 		expand_single_inheritance_child(root, parentrte, parentRTindex,
 										parentrel, top_parentrc, childrel,
-										appinfos, &childrte, &childRTindex);
+										&childrte, &childRTindex);
+
+		/* Create the otherrel RelOptInfo too. */
+		childrelinfo = build_simple_rel(root, childRTindex, relinfo);
+		relinfo->part_rels[i] = childrelinfo;
 
 		/* If this child is itself partitioned, recurse */
 		if (childrel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
-			expand_partitioned_rtentry(root, childrte, childRTindex,
-									   childrel, top_parentrc, lockmode,
-									   appinfos);
+			expand_partitioned_rtentry(root, childrelinfo,
+									   childrte, childRTindex,
+									   childrel, top_parentrc, lockmode);
 
 		/* Close child relation, but keep locks */
 		table_close(childrel, NoLock);
@@ -355,7 +411,7 @@ static void
 expand_single_inheritance_child(PlannerInfo *root, RangeTblEntry *parentrte,
 								Index parentRTindex, Relation parentrel,
 								PlanRowMark *top_parentrc, Relation childrel,
-								List **appinfos, RangeTblEntry **childrte_p,
+								RangeTblEntry **childrte_p,
 								Index *childRTindex_p)
 {
 	Query	   *parse = root->parse;
@@ -367,8 +423,8 @@ expand_single_inheritance_child(PlannerInfo *root, RangeTblEntry *parentrte,
 
 	/*
 	 * Build an RTE for the child, and attach to query's rangetable list. We
-	 * copy most fields of the parent's RTE, but replace relation OID and
-	 * relkind, and set inh = false.  Also, set requiredPerms to zero since
+	 * copy most fields of the parent's RTE, but replace relation OID,
+	 * relkind, and inh for the child.  Also, set requiredPerms to zero since
 	 * all required permissions checks are done on the original RTE. Likewise,
 	 * set the child's securityQuals to empty, because we only want to apply
 	 * the parent's RLS conditions regardless of what RLS properties
@@ -400,7 +456,7 @@ expand_single_inheritance_child(PlannerInfo *root, RangeTblEntry *parentrte,
 	 */
 	appinfo = make_append_rel_info(parentrel, childrel,
 								   parentRTindex, childRTindex);
-	*appinfos = lappend(*appinfos, appinfo);
+	root->append_rel_list = lappend(root->append_rel_list, appinfo);
 
 	/*
 	 * Translate the column permissions bitmaps to the child's attnums (we
@@ -423,6 +479,16 @@ expand_single_inheritance_child(PlannerInfo *root, RangeTblEntry *parentrte,
 														 appinfo->translated_vars);
 	}
 
+	/*
+	 * Store the RTE and appinfo in the respective PlannerInfo arrays, which
+	 * the caller must already have allocated space for.
+	 */
+	Assert(childRTindex < root->simple_rel_array_size);
+	Assert(root->simple_rte_array[childRTindex] == NULL);
+	root->simple_rte_array[childRTindex] = childrte;
+	Assert(root->append_rel_array[childRTindex] == NULL);
+	root->append_rel_array[childRTindex] = appinfo;
+
 	/*
 	 * Build a PlanRowMark if parent is marked FOR UPDATE/SHARE.
 	 */
@@ -443,7 +509,7 @@ expand_single_inheritance_child(PlannerInfo *root, RangeTblEntry *parentrte,
 		/*
 		 * We mark RowMarks for partitioned child tables as parent RowMarks so
 		 * that the executor ignores them (except their existence means that
-		 * the child tables be locked using appropriate mode).
+		 * the child tables will be locked using the appropriate mode).
 		 */
 		childrc->isParent = (childrte->relkind == RELKIND_PARTITIONED_TABLE);
 
@@ -505,3 +571,169 @@ translate_col_privs(const Bitmapset *parent_privs,
 
 	return child_privs;
 }
+
+/*
+ * expand_appendrel_subquery
+ *		Add "other rel" RelOptInfos for the children of an appendrel baserel
+ *
+ * "rel" is a subquery relation that has the rte->inh flag set, meaning it
+ * is a UNION ALL subquery that's been flattened into an appendrel, with
+ * child subqueries listed in root->append_rel_list.  We need to build
+ * a RelOptInfo for each child relation so that we can plan scans on them.
+ */
+static void
+expand_appendrel_subquery(PlannerInfo *root, RelOptInfo *rel,
+						  RangeTblEntry *rte, Index rti)
+{
+	ListCell   *l;
+
+	foreach(l, root->append_rel_list)
+	{
+		AppendRelInfo *appinfo = (AppendRelInfo *) lfirst(l);
+		Index		childRTindex = appinfo->child_relid;
+		RangeTblEntry *childrte;
+		RelOptInfo *childrel;
+
+		/* append_rel_list contains all append rels; ignore others */
+		if (appinfo->parent_relid != rti)
+			continue;
+
+		/* find the child RTE, which should already exist */
+		Assert(childRTindex < root->simple_rel_array_size);
+		childrte = root->simple_rte_array[childRTindex];
+		Assert(childrte != NULL);
+
+		/* Build the child RelOptInfo. */
+		childrel = build_simple_rel(root, childRTindex, rel);
+
+		/* Child may itself be an inherited rel, either table or subquery. */
+		if (childrte->inh)
+			expand_inherited_rtentry(root, childrel, childrte, childRTindex);
+	}
+}
+
+
+/*
+ * apply_child_basequals
+ *		Populate childrel's base restriction quals from parent rel's quals,
+ *		translating them using appinfo.
+ *
+ * If any of the resulting clauses evaluate to constant false or NULL, we
+ * return false and don't apply any quals.  Caller should mark the relation as
+ * a dummy rel in this case, since it doesn't need to be scanned.
+ */
+bool
+apply_child_basequals(PlannerInfo *root, RelOptInfo *parentrel,
+					  RelOptInfo *childrel, RangeTblEntry *childRTE,
+					  AppendRelInfo *appinfo)
+{
+	List	   *childquals;
+	Index		cq_min_security;
+	ListCell   *lc;
+
+	/*
+	 * The child rel's targetlist might contain non-Var expressions, which
+	 * means that substitution into the quals could produce opportunities for
+	 * const-simplification, and perhaps even pseudoconstant quals. Therefore,
+	 * transform each RestrictInfo separately to see if it reduces to a
+	 * constant or pseudoconstant.  (We must process them separately to keep
+	 * track of the security level of each qual.)
+	 */
+	childquals = NIL;
+	cq_min_security = UINT_MAX;
+	foreach(lc, parentrel->baserestrictinfo)
+	{
+		RestrictInfo *rinfo = (RestrictInfo *) lfirst(lc);
+		Node	   *childqual;
+		ListCell   *lc2;
+
+		Assert(IsA(rinfo, RestrictInfo));
+		childqual = adjust_appendrel_attrs(root,
+										   (Node *) rinfo->clause,
+										   1, &appinfo);
+		childqual = eval_const_expressions(root, childqual);
+		/* check for flat-out constant */
+		if (childqual && IsA(childqual, Const))
+		{
+			if (((Const *) childqual)->constisnull ||
+				!DatumGetBool(((Const *) childqual)->constvalue))
+			{
+				/* Restriction reduces to constant FALSE or NULL */
+				return false;
+			}
+			/* Restriction reduces to constant TRUE, so drop it */
+			continue;
+		}
+		/* might have gotten an AND clause, if so flatten it */
+		foreach(lc2, make_ands_implicit((Expr *) childqual))
+		{
+			Node	   *onecq = (Node *) lfirst(lc2);
+			bool		pseudoconstant;
+
+			/* check for pseudoconstant (no Vars or volatile functions) */
+			pseudoconstant =
+				!contain_vars_of_level(onecq, 0) &&
+				!contain_volatile_functions(onecq);
+			if (pseudoconstant)
+			{
+				/* tell createplan.c to check for gating quals */
+				root->hasPseudoConstantQuals = true;
+			}
+			/* reconstitute RestrictInfo with appropriate properties */
+			childquals = lappend(childquals,
+								 make_restrictinfo((Expr *) onecq,
+												   rinfo->is_pushed_down,
+												   rinfo->outerjoin_delayed,
+												   pseudoconstant,
+												   rinfo->security_level,
+												   NULL, NULL, NULL));
+			/* track minimum security level among child quals */
+			cq_min_security = Min(cq_min_security, rinfo->security_level);
+		}
+	}
+
+	/*
+	 * In addition to the quals inherited from the parent, we might have
+	 * securityQuals associated with this particular child node.  (Currently
+	 * this can only happen in appendrels originating from UNION ALL;
+	 * inheritance child tables don't have their own securityQuals, see
+	 * expand_single_inheritance_child().)  Pull any such securityQuals up
+	 * into the baserestrictinfo for the child.  This is similar to
+	 * process_security_barrier_quals() for the parent rel, except that we
+	 * can't make any general deductions from such quals, since they don't
+	 * hold for the whole appendrel.
+	 */
+	if (childRTE->securityQuals)
+	{
+		Index		security_level = 0;
+
+		foreach(lc, childRTE->securityQuals)
+		{
+			List	   *qualset = (List *) lfirst(lc);
+			ListCell   *lc2;
+
+			foreach(lc2, qualset)
+			{
+				Expr	   *qual = (Expr *) lfirst(lc2);
+
+				/* not likely that we'd see constants here, so no check */
+				childquals = lappend(childquals,
+									 make_restrictinfo(qual,
+													   true, false, false,
+													   security_level,
+													   NULL, NULL, NULL));
+				cq_min_security = Min(cq_min_security, security_level);
+			}
+			security_level++;
+		}
+		Assert(security_level <= root->qual_security_level);
+	}
+
+	/*
+	 * OK, we've got all the baserestrictinfo quals for this child.
+	 */
+	childrel->baserestrictinfo = childquals;
+	childrel->baserestrict_min_security = cq_min_security;
+
+	return true;
+}

src/backend/optimizer/util/plancat.c

@@ -2113,7 +2113,10 @@ set_relation_partition_info(PlannerInfo *root, RelOptInfo *rel,
 {
 	PartitionDesc partdesc;
 
-	Assert(relation->rd_rel->relkind == RELKIND_PARTITIONED_TABLE);
+	/* Create the PartitionDirectory infrastructure if we didn't already */
+	if (root->glob->partition_directory == NULL)
+		root->glob->partition_directory =
+			CreatePartitionDirectory(CurrentMemoryContext);
 
 	partdesc = PartitionDirectoryLookup(root->glob->partition_directory,
 										relation);

src/backend/optimizer/util/relnode.c

@@ -20,11 +20,11 @@
 #include "optimizer/appendinfo.h"
 #include "optimizer/clauses.h"
 #include "optimizer/cost.h"
+#include "optimizer/inherit.h"
 #include "optimizer/pathnode.h"
 #include "optimizer/paths.h"
 #include "optimizer/placeholder.h"
 #include "optimizer/plancat.h"
-#include "optimizer/prep.h"
 #include "optimizer/restrictinfo.h"
 #include "optimizer/tlist.h"
 #include "partitioning/partbounds.h"
@@ -131,6 +131,49 @@ setup_append_rel_array(PlannerInfo *root)
 	}
 }
 
+/*
+ * expand_planner_arrays
+ *		Expand the PlannerInfo's per-RTE arrays by add_size members
+ *		and initialize the newly added entries to NULLs
+ */
+void
+expand_planner_arrays(PlannerInfo *root, int add_size)
+{
+	int			new_size;
+
+	Assert(add_size > 0);
+
+	new_size = root->simple_rel_array_size + add_size;
+
+	root->simple_rte_array = (RangeTblEntry **)
+		repalloc(root->simple_rte_array,
+				 sizeof(RangeTblEntry *) * new_size);
+	MemSet(root->simple_rte_array + root->simple_rel_array_size,
+		   0, sizeof(RangeTblEntry *) * add_size);
+
+	root->simple_rel_array = (RelOptInfo **)
+		repalloc(root->simple_rel_array,
+				 sizeof(RelOptInfo *) * new_size);
+	MemSet(root->simple_rel_array + root->simple_rel_array_size,
+		   0, sizeof(RelOptInfo *) * add_size);
+
+	if (root->append_rel_array)
+	{
+		root->append_rel_array = (AppendRelInfo **)
+			repalloc(root->append_rel_array,
+					 sizeof(AppendRelInfo *) * new_size);
+		MemSet(root->append_rel_array + root->simple_rel_array_size,
+			   0, sizeof(AppendRelInfo *) * add_size);
+	}
+	else
+	{
+		root->append_rel_array = (AppendRelInfo **)
+			palloc0(sizeof(AppendRelInfo *) * new_size);
+	}
+
+	root->simple_rel_array_size = new_size;
+}
+
 /*
  * build_simple_rel
  *	  Construct a new RelOptInfo for a base relation or 'other' relation.
@@ -281,93 +324,42 @@ build_simple_rel(PlannerInfo *root, int relid, RelOptInfo *parent)
 			break;
 	}
 
-	/* Save the finished struct in the query's simple_rel_array */
-	root->simple_rel_array[relid] = rel;
-
 	/*
 	 * This is a convenient spot at which to note whether rels participating
 	 * in the query have any securityQuals attached.  If so, increase
 	 * root->qual_security_level to ensure it's larger than the maximum
-	 * security level needed for securityQuals.
+	 * security level needed for securityQuals.  (Must do this before we call
+	 * apply_child_basequals, else we'll hit an Assert therein.)
 	 */
 	if (rte->securityQuals)
 		root->qual_security_level = Max(root->qual_security_level,
 										list_length(rte->securityQuals));
 
-	return rel;
-}
-
-/*
- * add_appendrel_other_rels
- *		Add "other rel" RelOptInfos for the children of an appendrel baserel
- *
- * "rel" is a relation that (still) has the rte->inh flag set, meaning it
- * has appendrel children listed in root->append_rel_list.  We need to build
- * a RelOptInfo for each child relation so that we can plan scans on them.
- * (The parent relation might be a partitioned table, a table with
- * traditional inheritance children, or a flattened UNION ALL subquery.)
- */
-void
-add_appendrel_other_rels(PlannerInfo *root, RelOptInfo *rel, Index rti)
-{
-	int			cnt_parts = 0;
-	ListCell   *l;
-
 	/*
-	 * If rel is a partitioned table, then we also need to build a part_rels
-	 * array so that the child RelOptInfos can be conveniently accessed from
-	 * the parent.
+	 * Copy the parent's quals to the child, with appropriate substitution of
+	 * variables.  If any constant false or NULL clauses turn up, we can mark
+	 * the child as dummy right away.  (We must do this immediately so that
+	 * pruning works correctly when recursing in expand_partitioned_rtentry.)
 	 */
-	if (rel->part_scheme != NULL)
-	{
-		Assert(rel->nparts > 0);
-		rel->part_rels = (RelOptInfo **)
-			palloc0(sizeof(RelOptInfo *) * rel->nparts);
-	}
-
-	foreach(l, root->append_rel_list)
+	if (parent)
 	{
-		AppendRelInfo *appinfo = (AppendRelInfo *) lfirst(l);
-		Index		childRTindex = appinfo->child_relid;
-		RangeTblEntry *childrte;
-		RelOptInfo *childrel;
-
-		/* append_rel_list contains all append rels; ignore others */
-		if (appinfo->parent_relid != rti)
-			continue;
-
-		/* find the child RTE, which should already exist */
-		Assert(childRTindex < root->simple_rel_array_size);
-		childrte = root->simple_rte_array[childRTindex];
-		Assert(childrte != NULL);
+		AppendRelInfo *appinfo = root->append_rel_array[relid];
 
-		/* build child RelOptInfo, and add to main query data structures */
-		childrel = build_simple_rel(root, childRTindex, rel);
-
-		/*
-		 * If rel is a partitioned table, fill in the part_rels array.  The
-		 * order in which child tables appear in append_rel_list is the same
-		 * as the order in which they appear in the parent's PartitionDesc, so
-		 * assigning partitions like this works.
-		 */
-		if (rel->part_scheme != NULL)
-		{
-			Assert(cnt_parts < rel->nparts);
-			rel->part_rels[cnt_parts++] = childrel;
-		}
-
-		/* Child may itself be an inherited relation. */
-		if (childrte->inh)
+		Assert(appinfo != NULL);
+		if (!apply_child_basequals(root, parent, rel, rte, appinfo))
 		{
-			/* Only relation and subquery RTEs can have children. */
-			Assert(childrte->rtekind == RTE_RELATION ||
-				   childrte->rtekind == RTE_SUBQUERY);
-			add_appendrel_other_rels(root, childrel, childRTindex);
+			/*
+			 * Some restriction clause reduced to constant FALSE or NULL after
+			 * substitution, so this child need not be scanned.
+			 */
+			mark_dummy_rel(rel);
 		}
 	}
 
-	/* We should have filled all of the part_rels array if it's partitioned */
-	Assert(cnt_parts == rel->nparts);
+	/* Save the finished struct in the query's simple_rel_array */
+	root->simple_rel_array[relid] = rel;
+
+	return rel;
 }
 
 /*

src/backend/partitioning/partprune.c

@@ -45,6 +45,7 @@
 #include "nodes/makefuncs.h"
 #include "nodes/nodeFuncs.h"
 #include "optimizer/appendinfo.h"
+#include "optimizer/cost.h"
 #include "optimizer/optimizer.h"
 #include "optimizer/pathnode.h"
 #include "parser/parsetree.h"
@@ -474,18 +475,24 @@ make_partitionedrel_pruneinfo(PlannerInfo *root, RelOptInfo *parentrel,
 		 * is, not pruned already).
 		 */
 		subplan_map = (int *) palloc(nparts * sizeof(int));
+		memset(subplan_map, -1, nparts * sizeof(int));
 		subpart_map = (int *) palloc(nparts * sizeof(int));
-		relid_map = (Oid *) palloc(nparts * sizeof(Oid));
+		memset(subpart_map, -1, nparts * sizeof(int));
+		relid_map = (Oid *) palloc0(nparts * sizeof(Oid));
 		present_parts = NULL;
 
 		for (i = 0; i < nparts; i++)
 		{
 			RelOptInfo *partrel = subpart->part_rels[i];
-			int			subplanidx = relid_subplan_map[partrel->relid] - 1;
-			int			subpartidx = relid_subpart_map[partrel->relid] - 1;
+			int			subplanidx;
+			int			subpartidx;
 
-			subplan_map[i] = subplanidx;
-			subpart_map[i] = subpartidx;
+			/* Skip processing pruned partitions. */
+			if (partrel == NULL)
+				continue;
+
+			subplan_map[i] = subplanidx = relid_subplan_map[partrel->relid] - 1;
+			subpart_map[i] = subpartidx = relid_subpart_map[partrel->relid] - 1;
 			relid_map[i] = planner_rt_fetch(partrel->relid, root)->relid;
 			if (subplanidx >= 0)
 			{
@@ -567,29 +574,33 @@ gen_partprune_steps(RelOptInfo *rel, List *clauses, bool *contradictory)
 
 /*
  * prune_append_rel_partitions
- *		Returns RT indexes of the minimum set of child partitions which must
- *		be scanned to satisfy rel's baserestrictinfo quals.
+ *		Returns indexes into rel->part_rels of the minimum set of child
+ *		partitions which must be scanned to satisfy rel's baserestrictinfo
+ *		quals.
  *
  * Callers must ensure that 'rel' is a partitioned table.
  */
-Relids
+Bitmapset *
 prune_append_rel_partitions(RelOptInfo *rel)
 {
-	Relids		result;
 	List	   *clauses = rel->baserestrictinfo;
 	List	   *pruning_steps;
 	bool		contradictory;
 	PartitionPruneContext context;
-	Bitmapset  *partindexes;
-	int			i;
 
-	Assert(clauses != NIL);
 	Assert(rel->part_scheme != NULL);
 
 	/* If there are no partitions, return the empty set */
 	if (rel->nparts == 0)
 		return NULL;
 
+	/*
+	 * If pruning is disabled or if there are no clauses to prune with, return
+	 * all partitions.
+	 */
+	if (!enable_partition_pruning || clauses == NIL)
+		return bms_add_range(NULL, 0, rel->nparts - 1);
+
 	/*
 	 * Process clauses.  If the clauses are found to be contradictory, we can
 	 * return the empty set.
@@ -617,15 +628,7 @@ prune_append_rel_partitions(RelOptInfo *rel)
 	context.evalexecparams = false;
 
 	/* Actual pruning happens here. */
-	partindexes = get_matching_partitions(&context, pruning_steps);
-
-	/* Add selected partitions' RT indexes to result. */
-	i = -1;
-	result = NULL;
-	while ((i = bms_next_member(partindexes, i)) >= 0)
-		result = bms_add_member(result, rel->part_rels[i]->relid);
-
-	return result;
+	return get_matching_partitions(&context, pruning_steps);
 }
 
 /*

src/include/nodes/plannodes.h

@@ -1103,6 +1103,7 @@ typedef struct PartitionPruneInfo
  * it is -1 if the partition is a leaf or has been pruned.  Note that subplan
  * indexes, as stored in 'subplan_map', are global across the parent plan
  * node, but partition indexes are valid only within a particular hierarchy.
+ * relid_map[p] contains the partition's OID, or 0 if the partition was pruned.
  */
 typedef struct PartitionedRelPruneInfo
 {
@@ -1115,7 +1116,7 @@ typedef struct PartitionedRelPruneInfo
 	int			nexprs;			/* Length of hasexecparam[] */
 	int		   *subplan_map;	/* subplan index by partition index, or -1 */
 	int		   *subpart_map;	/* subpart index by partition index, or -1 */
-	Oid		   *relid_map;		/* relation OID by partition index, or -1 */
+	Oid		   *relid_map;		/* relation OID by partition index, or 0 */
 	bool	   *hasexecparam;	/* true if corresponding pruning_step contains
 								 * any PARAM_EXEC Params. */
 	bool		do_initial_prune;	/* true if pruning should be performed

src/include/optimizer/inherit.h

@@ -17,6 +17,11 @@
 #include "nodes/pathnodes.h"
 
 
-extern void expand_inherited_tables(PlannerInfo *root);
+extern void expand_inherited_rtentry(PlannerInfo *root, RelOptInfo *rel,
+						 RangeTblEntry *rte, Index rti);
+
+extern bool apply_child_basequals(PlannerInfo *root, RelOptInfo *parentrel,
+					  RelOptInfo *childrel, RangeTblEntry *childRTE,
+					  AppendRelInfo *appinfo);
 
 #endif							/* INHERIT_H */

src/include/optimizer/pathnode.h

@@ -277,10 +277,9 @@ extern Path *reparameterize_path_by_child(PlannerInfo *root, Path *path,
  */
 extern void setup_simple_rel_arrays(PlannerInfo *root);
 extern void setup_append_rel_array(PlannerInfo *root);
+extern void expand_planner_arrays(PlannerInfo *root, int add_size);
 extern RelOptInfo *build_simple_rel(PlannerInfo *root, int relid,
 				 RelOptInfo *parent);
-extern void add_appendrel_other_rels(PlannerInfo *root, RelOptInfo *rel,
-						 Index rti);
 extern RelOptInfo *find_base_rel(PlannerInfo *root, int relid);
 extern RelOptInfo *find_join_rel(PlannerInfo *root, Relids relids);
 extern RelOptInfo *build_join_rel(PlannerInfo *root,

src/test/regress/expected/partition_aggregate.out

@@ -144,7 +144,7 @@ SELECT c, sum(a) FROM pagg_tab WHERE 1 = 2 GROUP BY c;
            QUERY PLAN           
 --------------------------------
  HashAggregate
-   Group Key: pagg_tab.c
+   Group Key: c
    ->  Result
          One-Time Filter: false
 (4 rows)
@@ -159,7 +159,7 @@ SELECT c, sum(a) FROM pagg_tab WHERE c = 'x' GROUP BY c;
            QUERY PLAN           
 --------------------------------
  GroupAggregate
-   Group Key: pagg_tab.c
+   Group Key: c
    ->  Result
          One-Time Filter: false
 (4 rows)

src/test/regress/expected/partition_prune.out

@@ -2568,6 +2568,60 @@ table ab;
  1 | 3
 (1 row)
 
+-- Test UPDATE where source relation has run-time pruning enabled
+truncate ab;
+insert into ab values (1, 1), (1, 2), (1, 3), (2, 1);
+explain (analyze, costs off, summary off, timing off)
+update ab_a1 set b = 3 from ab_a2 where ab_a2.b = (select 1);
+                              QUERY PLAN                              
+----------------------------------------------------------------------
+ Update on ab_a1 (actual rows=0 loops=1)
+   Update on ab_a1_b1
+   Update on ab_a1_b2
+   Update on ab_a1_b3
+   InitPlan 1 (returns $0)
+     ->  Result (actual rows=1 loops=1)
+   ->  Nested Loop (actual rows=1 loops=1)
+         ->  Seq Scan on ab_a1_b1 (actual rows=1 loops=1)
+         ->  Materialize (actual rows=1 loops=1)
+               ->  Append (actual rows=1 loops=1)
+                     ->  Seq Scan on ab_a2_b1 (actual rows=1 loops=1)
+                           Filter: (b = $0)
+                     ->  Seq Scan on ab_a2_b2 (never executed)
+                           Filter: (b = $0)
+                     ->  Seq Scan on ab_a2_b3 (never executed)
+                           Filter: (b = $0)
+   ->  Nested Loop (actual rows=1 loops=1)
+         ->  Seq Scan on ab_a1_b2 (actual rows=1 loops=1)
+         ->  Materialize (actual rows=1 loops=1)
+               ->  Append (actual rows=1 loops=1)
+                     ->  Seq Scan on ab_a2_b1 (actual rows=1 loops=1)
+                           Filter: (b = $0)
+                     ->  Seq Scan on ab_a2_b2 (never executed)
+                           Filter: (b = $0)
+                     ->  Seq Scan on ab_a2_b3 (never executed)
+                           Filter: (b = $0)
+   ->  Nested Loop (actual rows=1 loops=1)
+         ->  Seq Scan on ab_a1_b3 (actual rows=1 loops=1)
+         ->  Materialize (actual rows=1 loops=1)
+               ->  Append (actual rows=1 loops=1)
+                     ->  Seq Scan on ab_a2_b1 (actual rows=1 loops=1)
+                           Filter: (b = $0)
+                     ->  Seq Scan on ab_a2_b2 (never executed)
+                           Filter: (b = $0)
+                     ->  Seq Scan on ab_a2_b3 (never executed)
+                           Filter: (b = $0)
+(36 rows)
+
+select tableoid::regclass, * from ab;
+ tableoid | a | b 
+----------+---+---
+ ab_a1_b3 | 1 | 3
+ ab_a1_b3 | 1 | 3
+ ab_a1_b3 | 1 | 3
+ ab_a2_b1 | 2 | 1
+(4 rows)
+
 drop table ab, lprt_a;
 -- Join
 create table tbl1(col1 int);

src/test/regress/sql/partition_prune.sql

@@ -588,6 +588,13 @@ explain (analyze, costs off, summary off, timing off)
 update ab_a1 set b = 3 from ab where ab.a = 1 and ab.a = ab_a1.a;
 table ab;
 
+-- Test UPDATE where source relation has run-time pruning enabled
+truncate ab;
+insert into ab values (1, 1), (1, 2), (1, 3), (2, 1);
+explain (analyze, costs off, summary off, timing off)
+update ab_a1 set b = 3 from ab_a2 where ab_a2.b = (select 1);
+select tableoid::regclass, * from ab;
+
 drop table ab, lprt_a;
 
 -- Join