From: Tomas Vondra <tomas@2ndquadrant.com>
Date: Sun, 22 Jan 2017 17:57:40 +0000 (+0100)
Subject: add a redistribution missing in create_distinct_paths
X-Git-Tag: XL_10_R1BETA1~410
X-Git-Url: http://git.postgresql.org/gitweb/static/gitweb.js?a=commitdiff_plain;h=7178df974a057d005c1977c6a714923d83bbf273;p=postgres-xl.git

add a redistribution missing in create_distinct_paths

A redistribution was missing in the loop handling paths already
sorted for the DISTINCT case. So add it there.
---

diff --git a/src/backend/optimizer/plan/planner.c b/src/backend/optimizer/plan/planner.c
index 2f1dc845b8..4ea83f0b0d 100644
--- a/src/backend/optimizer/plan/planner.c
+++ b/src/backend/optimizer/plan/planner.c
@@ -4929,6 +4929,16 @@ create_distinct_paths(PlannerInfo *root,
 
 			if (pathkeys_contained_in(needed_pathkeys, path->pathkeys))
 			{
+				/*
+				 * Make sure the distribution matches the distinct clause,
+				 * needed by the UNIQUE path.
+				 *
+				 * FIXME This could probably benefit from pushing a UNIQUE
+				 * to the remote side, and only doing a merge locally.
+				 */
+				if (!grouping_distribution_match(root, parse, path, parse->distinctClause))
+					path = create_remotesubplan_path(root, path, NULL);
+
 				add_path(distinct_rel, (Path *)
 						 create_upper_unique_path(root, distinct_rel,
 												  path,