From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Fri, 27 Aug 2021 23:42:42 +0000 (-0400)
Subject: Count SP-GiST index scans in pg_stat statistics.
X-Git-Tag: REL_14_RC1~78
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=e84d4810cd47d83a6a864fa33db74bcc5570dd76;p=thirdparty%2Fpostgresql.git

Count SP-GiST index scans in pg_stat statistics.

Somehow, spgist overlooked the need to call pgstat_count_index_scan().
Hence, pg_stat_all_indexes.idx_scan and equivalent columns never
became nonzero for an SP-GiST index, although the related per-tuple
counters worked fine.

This fix works a bit differently from other index AMs, in that the
counter increment occurs in spgrescan not spggettuple/spggetbitmap.
It looks like this won't make the user-visible semantics noticeably
different, so I won't go to the trouble of introducing an is-this-
the-first-call flag just to make the counter bumps happen in the
same places.

Per bug #17163 from Christian Quest.  Back-patch to all supported
versions.

Discussion: https://postgr.es/m/17163-b8c5cc88322a5e92@postgresql.org
---

diff --git a/src/backend/access/spgist/spgscan.c b/src/backend/access/spgist/spgscan.c
index e14b9fa573a..401a1a83432 100644
--- a/src/backend/access/spgist/spgscan.c
+++ b/src/backend/access/spgist/spgscan.c
@@ -19,6 +19,7 @@
 #include "access/relscan.h"
 #include "access/spgist_private.h"
 #include "miscadmin.h"
+#include "pgstat.h"
 #include "storage/bufmgr.h"
 #include "utils/datum.h"
 #include "utils/float.h"
@@ -419,6 +420,9 @@ spgrescan(IndexScanDesc scan, ScanKey scankey, int nscankeys,
 
 	/* set up starting queue entries */
 	resetSpGistScanOpaque(so);
+
+	/* count an indexscan for stats */
+	pgstat_count_index_scan(scan->indexRelation);
 }
 
 void