Fix segfault on DELETE .. USING with joins of partitioned tables

Author: ildus

expected/pathman_upd_del.out

@@ -13,6 +13,13 @@ SET enable_seqscan = OFF;
 /* Temporary table for JOINs */
 CREATE TABLE test.tmp (id INTEGER NOT NULL, value INTEGER NOT NULL);
 INSERT INTO test.tmp VALUES (1, 1), (2, 2);
+CREATE TABLE test.tmp2 (id INTEGER NOT NULL, value INTEGER NOT NULL);
+SELECT pathman.create_range_partitions('test.tmp2', 'id', 1, 1, 10);
+ create_range_partitions 
+-------------------------
+                      10
+(1 row)
+
 /* Partition table by RANGE */
 CREATE TABLE test.range_rel (
 	id		SERIAL PRIMARY KEY,
@@ -258,7 +265,10 @@ WITH q AS (DELETE FROM test.tmp t
 		   RETURNING *)
 DELETE FROM test.tmp USING q;
 ROLLBACK;
+/* Test special rule for CTE; DELETE + USING with partitioned table */
+DELETE FROM test.range_rel r USING test.tmp2 t WHERE t.id = r.id;
+ERROR:  pg_pathman doesn't support DELETE queries with joining of partitioned tables
 DROP SCHEMA test CASCADE;
-NOTICE:  drop cascades to 15 other objects
+NOTICE:  drop cascades to 27 other objects
 DROP EXTENSION pg_pathman CASCADE;
 DROP SCHEMA pathman CASCADE;

sql/pathman_upd_del.sql

@@ -21,6 +21,9 @@ SET enable_seqscan = OFF;
 CREATE TABLE test.tmp (id INTEGER NOT NULL, value INTEGER NOT NULL);
 INSERT INTO test.tmp VALUES (1, 1), (2, 2);
 
+CREATE TABLE test.tmp2 (id INTEGER NOT NULL, value INTEGER NOT NULL);
+SELECT pathman.create_range_partitions('test.tmp2', 'id', 1, 1, 10);
+
 
 /* Partition table by RANGE */
 CREATE TABLE test.range_rel (
@@ -164,7 +167,8 @@ WITH q AS (DELETE FROM test.tmp t
 DELETE FROM test.tmp USING q;
 ROLLBACK;
 
-
+/* Test special rule for CTE; DELETE + USING with partitioned table */
+DELETE FROM test.range_rel r USING test.tmp2 t WHERE t.id = r.id;
 
 DROP SCHEMA test CASCADE;
 DROP EXTENSION pg_pathman CASCADE;

src/hooks.c

@@ -99,6 +99,23 @@ pathman_join_pathlist_hook(PlannerInfo *root,
 	if (innerrel->reloptkind != RELOPT_BASEREL)
 		return;
 
+	/* check if query DELETE FROM .. USING .. */
+	if (root->parse->commandType == CMD_DELETE && jointype == JOIN_INNER)
+	{
+		int x = -1;
+		int count = 0;
+
+		while ((x = bms_next_member(joinrel->relids, x)) >= 0)
+			if (get_pathman_relation_info(root->simple_rte_array[x]->relid))
+				count += 1;
+
+		if (count > 1)
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("pg_pathman doesn't support DELETE queries with "\
+							"joining of partitioned tables")));
+	}
+
 	/* We shouldn't process tables with active children */
 	if (inner_rte->inh)
 		return;

src/pg_pathman.c

@@ -1916,6 +1916,9 @@ set_append_rel_pathlist(PlannerInfo *root, RelOptInfo *rel, Index rti,
 		childRTE = root->simple_rte_array[childRTindex];
 		childrel = root->simple_rel_array[childRTindex];
 
+		if (!childrel)
+			elog(ERROR, "could not make access paths to a relation");
+
 #if PG_VERSION_NUM >= 90600
 		/*
 		 * If parallelism is allowable for this query in general and for parent