Add tableoid junk column to processed_tlist only for top-level parent.

(Note that the column is added to RelOptInfo reltarget of all nodes in the
hierarchy anyway; but only tle with top-level varno must get to *main* tlist,
i.e. processed_tlist.)

Previously it was added for each parent in the tree, i.e. multiple times in case
of multi-level partitioning, leading to

ERROR: variable not found in subplan target lists

errors in setref.

As comments say, this code better be rewritten to actually let parent deal with
its isParent flag. And to recurce with toplever rc. Probably should be done if
adjacent bugs arise.

expected/pathman_subpartitions.out

@@ -424,6 +424,39 @@ UPDATE subpartitions.abc SET id1 = -1, id2 = -1 RETURNING tableoid::regclass, *;
 
 DROP TABLE subpartitions.abc CASCADE;
 NOTICE:  drop cascades to 9 other objects
+--- basic check how rowmark plays along with subparts; PGPRO-2755
+CREATE TABLE subpartitions.a1(n1 integer);
+CREATE TABLE subpartitions.a2(n1 integer not null, n2 integer not null);
+SELECT create_range_partitions('subpartitions.a2', 'n1', 1, 2, 0);
+ create_range_partitions 
+-------------------------
+                       0
+(1 row)
+
+SELECT add_range_partition('subpartitions.a2', 10, 20, 'subpartitions.a2_1020');
+  add_range_partition  
+-----------------------
+ subpartitions.a2_1020
+(1 row)
+
+SELECT create_range_partitions('subpartitions.a2_1020'::regclass, 'n2'::text, array[30,40], array['subpartitions.a2_1020_3040']);
+ create_range_partitions 
+-------------------------
+                       1
+(1 row)
+
+INSERT INTO subpartitions.a2 VALUES (10, 30), (11, 31), (12, 32), (19, 39);
+INSERT INTO subpartitions.a1 VALUES (12), (19), (20);
+SELECT a2.* FROM subpartitions.a1 JOIN subpartitions.a2 ON a2.n1=a1.n1 FOR UPDATE;
+ n1 | n2 
+----+----
+ 12 | 32
+ 19 | 39
+(2 rows)
+
+DROP TABLE subpartitions.a2 CASCADE;
+NOTICE:  drop cascades to 4 other objects
+DROP TABLE subpartitions.a1;
 DROP SCHEMA subpartitions CASCADE;
 NOTICE:  drop cascades to function subpartitions.partitions_tree(regclass,text)
 DROP EXTENSION pg_pathman;

sql/pathman_subpartitions.sql

@@ -139,8 +139,24 @@ SELECT tableoid::regclass, * FROM subpartitions.abc ORDER BY id1, id2, val;
 SET pg_pathman.enable_partitionrouter = ON;
 UPDATE subpartitions.abc SET id1 = -1, id2 = -1 RETURNING tableoid::regclass, *;
 
+DROP TABLE subpartitions.abc CASCADE;
+
+
+--- basic check how rowmark plays along with subparts; PGPRO-2755
+CREATE TABLE subpartitions.a1(n1 integer);
+CREATE TABLE subpartitions.a2(n1 integer not null, n2 integer not null);
+SELECT create_range_partitions('subpartitions.a2', 'n1', 1, 2, 0);
+
+SELECT add_range_partition('subpartitions.a2', 10, 20, 'subpartitions.a2_1020');
+SELECT create_range_partitions('subpartitions.a2_1020'::regclass, 'n2'::text, array[30,40], array['subpartitions.a2_1020_3040']);
+INSERT INTO subpartitions.a2 VALUES (10, 30), (11, 31), (12, 32), (19, 39);
+INSERT INTO subpartitions.a1 VALUES (12), (19), (20);
+
+SELECT a2.* FROM subpartitions.a1 JOIN subpartitions.a2 ON a2.n1=a1.n1 FOR UPDATE;
+
+DROP TABLE subpartitions.a2 CASCADE;
+DROP TABLE subpartitions.a1;
 
 
-DROP TABLE subpartitions.abc CASCADE;
 DROP SCHEMA subpartitions CASCADE;
 DROP EXTENSION pg_pathman;

src/include/rangeset.h

@@ -1,7 +1,6 @@
 /* ------------------------------------------------------------------------
  *
  * rangeset.h
- *		IndexRange functions
  *
  * Copyright (c) 2015-2016, Postgres Professional
  *
@@ -17,7 +16,10 @@
 
 
 /*
- * IndexRange contains a set of selected partitions.
+ * IndexRange is essentially a segment [lower; upper]. This module provides
+ * functions for efficient working (intersection, union) with Lists of
+ * IndexRange's; this is used for quick selection of partitions. Numbers are
+ * indexes of partitions in PartRelationInfo's children.
  */
 typedef struct {
 	/* lossy == should we use quals? */

src/pg_pathman.c

@@ -437,7 +437,7 @@ append_child_relation(PlannerInfo *root,
 	Relation		child_relation;
 	AppendRelInfo  *appinfo;
 	Index			child_rti;
-	PlanRowMark	   *child_rowmark;
+	PlanRowMark	   *child_rowmark = NULL;
 	Node		   *childqual;
 	List		   *childquals;
 	ListCell	   *lc1,
@@ -493,6 +493,10 @@ append_child_relation(PlannerInfo *root,
 
 
 	/* Create rowmarks required for child rels */
+	/*
+	 * XXX: vanilla recurses down with *top* rowmark, not immediate parent one.
+	 * Not sure about example where this matters though.
+	 */
 	if (parent_rowmark)
 	{
 		child_rowmark = makeNode(PlanRowMark);
@@ -511,6 +515,13 @@ append_child_relation(PlannerInfo *root,
 		root->rowMarks = lappend(root->rowMarks, child_rowmark);
 
 		/* Adjust tlist for RowMarks (see planner.c) */
+		/*
+		 * XXX Saner approach seems to
+		 *	1) Add tle to top parent and processed_tlist once in rel_pathlist_hook.
+		 *  2) Mark isParent = true
+		 *    *parent* knows it is parent, after all; why should child bother?
+		 *  3) Recursion (code executed in childs) starts at 2)
+		 */
 		if (!parent_rowmark->isParent && !root->parse->setOperations)
 		{
 			append_tle_for_rowmark(root, parent_rowmark);
@@ -636,6 +647,10 @@ append_child_relation(PlannerInfo *root,
 	if (parent_rte->relid != child_oid &&
 		child_relation->rd_rel->relhassubclass)
 	{
+		/* See XXX above */
+		if (child_rowmark)
+			child_rowmark->isParent = true;
+
 		pathman_rel_pathlist_hook(root,
 								  child_rel,
 								  child_rti,