From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Mon, 12 Oct 2020 22:01:34 +0000 (-0400)
Subject: Fix GiST buffering build to work when there are included columns.
X-Git-Tag: aio-before-rebase-2020-10-30~173
X-Git-Url: http://git.postgresql.org/gitweb/?a=commitdiff_plain;h=371668a8389d792279bd7aff8ca796e284f595df;p=users%2Fandresfreund%2Fpostgres.git

Fix GiST buffering build to work when there are included columns.

gistRelocateBuildBuffersOnSplit did not get the memo about which
attribute count to use.  This could lead to a crash if there were
included columns and buffering build was chosen.  (Because there
are random page-split decisions elsewhere in GiST index build,
the crashes are not entirely deterministic.)

Back-patch to v12 where GiST gained support for included columns.

Pavel Borisov

Discussion: https://postgr.es/m/CALT9ZEECCV5m7wvxg46PC-7x-EybUmnpupBGhSFMoAAay+r6HQ@mail.gmail.com
---

diff --git a/src/backend/access/gist/gistbuildbuffers.c b/src/backend/access/gist/gistbuildbuffers.c
index 4eab9bb83a..4ad67c88b4 100644
--- a/src/backend/access/gist/gistbuildbuffers.c
+++ b/src/backend/access/gist/gistbuildbuffers.c
@@ -666,7 +666,7 @@ gistRelocateBuildBuffersOnSplit(GISTBuildBuffers *gfbb, GISTSTATE *giststate,
 			zero_penalty = true;
 
 			/* Loop over index attributes. */
-			for (j = 0; j < r->rd_att->natts; j++)
+			for (j = 0; j < IndexRelationGetNumberOfKeyAttributes(r); j++)
 			{
 				float		usize;
 
@@ -692,7 +692,7 @@ gistRelocateBuildBuffersOnSplit(GISTBuildBuffers *gfbb, GISTSTATE *giststate,
 					which = i;
 					best_penalty[j] = usize;
 
-					if (j < r->rd_att->natts - 1)
+					if (j < IndexRelationGetNumberOfKeyAttributes(r) - 1)
 						best_penalty[j + 1] = -1;
 				}
 				else if (best_penalty[j] == usize)