4 files changed, 63 insertions, 46 deletions

diff --git a/src/backend/optimizer/plan/planmain.c b/src/backend/optimizer/plan/planmain.c
index 7a34abca048..b05adc70c4a 100644
--- a/src/backend/optimizer/plan/planmain.c
+++ b/src/backend/optimizer/plan/planmain.c
@@ -125,6 +125,12 @@ query_planner(PlannerInfo *root, List *tlist,
 	setup_simple_rel_arrays(root);
 
 	/*
+	 * Populate append_rel_array with each AppendRelInfo to allow direct
+	 * lookups by child relid.
+	 */
+	setup_append_rel_array(root);
+
+	/*
 	 * Construct RelOptInfo nodes for all base relations in query, and
 	 * indirectly for all appendrel member relations ("other rels").  This
 	 * will give us a RelOptInfo for every "simple" (non-join) rel involved in
diff --git a/src/backend/optimizer/plan/planner.c b/src/backend/optimizer/plan/planner.c
index 1f09fb6e6ad..fd45c9767df 100644
--- a/src/backend/optimizer/plan/planner.c
+++ b/src/backend/optimizer/plan/planner.c
@@ -1163,6 +1163,7 @@ inheritance_planner(PlannerInfo *root)
 	List	   *final_rtable = NIL;
 	int			save_rel_array_size = 0;
 	RelOptInfo **save_rel_array = NULL;
+	AppendRelInfo **save_append_rel_array = NULL;
 	List	   *subpaths = NIL;
 	List	   *subroots = NIL;
 	List	   *resultRelations = NIL;
@@ -1529,6 +1530,7 @@ inheritance_planner(PlannerInfo *root)
 		}
 		save_rel_array_size = subroot->simple_rel_array_size;
 		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 */
 		root->init_plans = subroot->init_plans;
@@ -1579,6 +1581,8 @@ inheritance_planner(PlannerInfo *root)
 	parse->rtable = final_rtable;
 	root->simple_rel_array_size = save_rel_array_size;
 	root->simple_rel_array = save_rel_array;
+	root->append_rel_array = save_append_rel_array;
+
 	/* Must reconstruct master's simple_rte_array, too */
 	root->simple_rte_array = (RangeTblEntry **)
 		palloc0((list_length(final_rtable) + 1) * sizeof(RangeTblEntry *));
diff --git a/src/backend/optimizer/prep/prepunion.c b/src/backend/optimizer/prep/prepunion.c
index 0ab4014be6d..2d470240d5d 100644
--- a/src/backend/optimizer/prep/prepunion.c
+++ b/src/backend/optimizer/prep/prepunion.c
@@ -167,6 +167,12 @@ plan_set_operations(PlannerInfo *root)
 	setup_simple_rel_arrays(root);
 
 	/*
+	 * Populate append_rel_array with each AppendRelInfo to allow direct
+	 * lookups by child relid.
+	 */
+	setup_append_rel_array(root);
+
+	/*
 	 * Find the leftmost component Query.  We need to use its column names for
 	 * all generated tlists (else SELECT INTO won't work right).
 	 */
@@ -2617,29 +2623,22 @@ build_child_join_sjinfo(PlannerInfo *root, SpecialJoinInfo *parent_sjinfo,
 AppendRelInfo **
 find_appinfos_by_relids(PlannerInfo *root, Relids relids, int *nappinfos)
 {
-	ListCell   *lc;
 	AppendRelInfo **appinfos;
 	int			cnt = 0;
+	int			i;
 
 	*nappinfos = bms_num_members(relids);
 	appinfos = (AppendRelInfo **) palloc(sizeof(AppendRelInfo *) * *nappinfos);
 
-	foreach(lc, root->append_rel_list)
+	i = -1;
+	while ((i = bms_next_member(relids, i)) >= 0)
 	{
-		AppendRelInfo *appinfo = lfirst(lc);
+		AppendRelInfo *appinfo = root->append_rel_array[i];
 
-		if (bms_is_member(appinfo->child_relid, relids))
-		{
-			appinfos[cnt] = appinfo;
-			cnt++;
+		if (!appinfo)
+			elog(ERROR, "child rel %d not found in append_rel_array", i);
 
-			/* Stop when we have gathered all the AppendRelInfos. */
-			if (cnt == *nappinfos)
-				return appinfos;
-		}
+		appinfos[cnt++] = appinfo;
 	}
-
-	/* Should have found the entries ... */
-	elog(ERROR, "did not find all requested child rels in append_rel_list");
-	return NULL;				/* not reached */
+	return appinfos;
 }
diff --git a/src/backend/optimizer/util/relnode.c b/src/backend/optimizer/util/relnode.c
index 82b78420e79..c69740eda6c 100644
--- a/src/backend/optimizer/util/relnode.c
+++ b/src/backend/optimizer/util/relnode.c
@@ -89,6 +89,43 @@ setup_simple_rel_arrays(PlannerInfo *root)
 }
 
 /*
+ * setup_append_rel_array
+ *		Populate the append_rel_array to allow direct lookups of
+ *		AppendRelInfos by child relid.
+ *
+ * The array remains unallocated if there are no AppendRelInfos.
+ */
+void
+setup_append_rel_array(PlannerInfo *root)
+{
+	ListCell   *lc;
+	int			size = list_length(root->parse->rtable) + 1;
+
+	if (root->append_rel_list == NIL)
+	{
+		root->append_rel_array = NULL;
+		return;
+	}
+
+	root->append_rel_array = (AppendRelInfo **)
+		palloc0(size * sizeof(AppendRelInfo *));
+
+	foreach(lc, root->append_rel_list)
+	{
+		AppendRelInfo *appinfo = lfirst_node(AppendRelInfo, lc);
+		int			child_relid = appinfo->child_relid;
+
+		/* Sanity check */
+		Assert(child_relid < size);
+
+		if (root->append_rel_array[child_relid])
+			elog(ERROR, "child relation already exists");
+
+		root->append_rel_array[child_relid] = appinfo;
+	}
+}
+
+/*
  * build_simple_rel
  *	  Construct a new RelOptInfo for a base relation or 'other' relation.
  */
@@ -1185,36 +1222,6 @@ fetch_upper_rel(PlannerInfo *root, UpperRelationKind kind, Relids relids)
 
 
 /*
- * find_childrel_appendrelinfo
- *		Get the AppendRelInfo associated with an appendrel child rel.
- *
- * This search could be eliminated by storing a link in child RelOptInfos,
- * but for now it doesn't seem performance-critical.  (Also, it might be
- * difficult to maintain such a link during mutation of the append_rel_list.)
- */
-AppendRelInfo *
-find_childrel_appendrelinfo(PlannerInfo *root, RelOptInfo *rel)
-{
-	Index		relid = rel->relid;
-	ListCell   *lc;
-
-	/* Should only be called on child rels */
-	Assert(rel->reloptkind == RELOPT_OTHER_MEMBER_REL);
-
-	foreach(lc, root->append_rel_list)
-	{
-		AppendRelInfo *appinfo = (AppendRelInfo *) lfirst(lc);
-
-		if (appinfo->child_relid == relid)
-			return appinfo;
-	}
-	/* should have found the entry ... */
-	elog(ERROR, "child rel %d not found in append_rel_list", relid);
-	return NULL;				/* not reached */
-}
-
-
-/*
  * find_childrel_parents
  *		Compute the set of parent relids of an appendrel child rel.
  *
@@ -1228,10 +1235,11 @@ find_childrel_parents(PlannerInfo *root, RelOptInfo *rel)
 	Relids		result = NULL;
 
 	Assert(rel->reloptkind == RELOPT_OTHER_MEMBER_REL);
+	Assert(rel->relid > 0 && rel->relid < root->simple_rel_array_size);
 
 	do
 	{
-		AppendRelInfo *appinfo = find_childrel_appendrelinfo(root, rel);
+		AppendRelInfo *appinfo = root->append_rel_array[rel->relid];
 		Index		prelid = appinfo->parent_relid;
 
 		result = bms_add_member(result, prelid);