postgres.git / summary / log / commit / refs
commit 3cd504254f604a37adefc2bd9d43a0a6041463fd
Author: Tom Lane <tgl@sss.pgh.pa.us>
Date: Thu Oct 13 23:45:58 2016 +0000
Fix handling of pgstat counters for TRUNCATE in a prepared transaction.
pgstat_twophase_postcommit is supposed to duplicate the math in
AtEOXact_PgStat, but it had missed out the bit about clearing
t_delta_live_tuples/t_delta_dead_tuples for a TRUNCATE.
It's harder than you might think to replicate the issue here, because
those counters would only be nonzero when a previous transaction in
the same backend had added/deleted tuples in the truncated table,
and those counts hadn't been sent to the stats collector yet.
Evident oversight in commit d42358efb. I've not added a regression
test for this; we tried to add one in d42358efb, and had to revert it
because it was too timing-sensitive for the buildfarm.
Back-patch to 9.5 where d42358efb came in.
Stas Kelvich
Discussion: <EB57BF68-C06D-4737-BDDC-4BA778F4E62B@postgrespro.ru>
src/backend/postmaster/pgstat.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/src/backend/postmaster/pgstat.c b/src/backend/postmaster/pgstat.c
index 0440f4a1d45..8f5e90be2a9 100644
--- a/src/backend/postmaster/pgstat.c
+++ b/src/backend/postmaster/pgstat.c
@@ -2227,7 +2227,12 @@ pgstat_twophase_postcommit(TransactionId xid, uint16 info,
pgstat_info->t_counts.t_tuples_updated += rec->tuples_updated;
pgstat_info->t_counts.t_tuples_deleted += rec->tuples_deleted;
pgstat_info->t_counts.t_truncated = rec->t_truncated;
-
+ if (rec->t_truncated)
+ {
+ /* forget live/dead stats seen by backend thus far */
+ pgstat_info->t_counts.t_delta_live_tuples = 0;
+ pgstat_info->t_counts.t_delta_dead_tuples = 0;
+ }
pgstat_info->t_counts.t_delta_live_tuples +=
rec->tuples_inserted - rec->tuples_deleted;
pgstat_info->t_counts.t_delta_dead_tuples +=
[parent: 3217ac3a9867]