From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Tue, 8 Mar 2016 21:50:32 +0000 (-0500)
Subject: Fix minor thinko in pathification code.
X-Git-Tag: REL9_6_BETA1~561
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=61fd218930db53079e5f001dd4ea2fd53afd1b95;p=postgresql

Fix minor thinko in pathification code.

I passed the wrong "root" struct to create_pathtarget in build_minmax_path.
Since the subroot is a clone of the outer root, this would not cause any
serious problems, but it would waste some cycles because
set_pathtarget_cost_width would not have access to Var width estimates
set up while running query_planner on the subroot.
---

diff --git a/src/backend/optimizer/plan/planagg.c b/src/backend/optimizer/plan/planagg.c
index 9d6c181e36..cefec7bdf1 100644
--- a/src/backend/optimizer/plan/planagg.c
+++ b/src/backend/optimizer/plan/planagg.c
@@ -465,7 +465,7 @@ build_minmax_path(PlannerInfo *root, MinMaxAggInfo *mminfo,
 	 * cheapest path.)
 	 */
 	sorted_path = apply_projection_to_path(subroot, final_rel, sorted_path,
-										   create_pathtarget(root, tlist));
+										   create_pathtarget(subroot, tlist));
 
 	/*
 	 * Determine cost to get just the first row of the presorted path.