postgres.git / summary / log / commit / refs

commit    8776c15c85322612b9bf79daf50f74be71c12e05
Author:   Tom Lane <tgl@sss.pgh.pa.us>
Date:     Wed Mar 09 15:56:36 2016 +0000
First released in: 9.6.0

    Fix incorrect tlist generation in create_gather_plan().
    
    This function is written as though Gather doesn't project; but it does.
    Even if it did not project, though, we must use build_path_tlist to ensure
    that the output columns receive correct sortgroupref labeling.
    
    Per report from Amit Kapila.


 src/backend/optimizer/plan/createplan.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/src/backend/optimizer/plan/createplan.c b/src/backend/optimizer/plan/createplan.c
index 0c2d593499d..5c06547931b 100644
--- a/src/backend/optimizer/plan/createplan.c
+++ b/src/backend/optimizer/plan/createplan.c
@@ -1360,11 +1360,17 @@ create_gather_plan(PlannerInfo *root, GatherPath *best_path)
 {
 	Gather	   *gather_plan;
 	Plan	   *subplan;
+	List	   *tlist;
 
-	/* Must insist that all children return the same tlist */
+	/*
+	 * Although the Gather node can project, we prefer to push down such work
+	 * to its child node, so demand an exact tlist from the child.
+	 */
 	subplan = create_plan_recurse(root, best_path->subpath, CP_EXACT_TLIST);
 
-	gather_plan = make_gather(subplan->targetlist,
+	tlist = build_path_tlist(root, &best_path->path);
+
+	gather_plan = make_gather(tlist,
 							  NIL,
 							  best_path->path.parallel_degree,
 							  best_path->single_copy,


[parent: aa09cd242fa7]