From: Michael Paquier Date: Thu, 1 Feb 2024 08:13:09 +0000 (+0900) Subject: Fix stats_fetch_consistency with stats for fixed-numbered objects X-Git-Tag: REL_16_2~17 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=781bc121de897c235ae731ad9f58dfd4075a1008;p=thirdparty%2Fpostgresql.git Fix stats_fetch_consistency with stats for fixed-numbered objects This impacts the statistics retrieved in transactions for the following views when updating the value of stats_fetch_consistency, leading to behaviors contrary to what is documented since 605994651b6a as an update of this parameter should discard all statistics snapshot data: - pg_stat_archiver - pg_stat_bgwriter - pg_stat_checkpointer - pg_stat_io - pg_stat_slru - pg_stat_wal For example, updating stats_fetch_consistency from "snapshot" to "cache" in a transaction did not re-fetch any fresh data, using data cached from the time when "snapshot" was in use. Author: Shinya Kato Discussion: https://postgr.es/m/d77fc5190d4dbe1738d77231488e768b@oss.nttdata.com Backpatch-through: 15 --- diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c index d743fc0b289..a220cb876d8 100644 --- a/src/backend/utils/activity/pgstat.c +++ b/src/backend/utils/activity/pgstat.c @@ -943,6 +943,9 @@ pgstat_snapshot_fixed(PgStat_Kind kind) Assert(pgstat_is_kind_valid(kind)); Assert(pgstat_get_kind_info(kind)->fixed_amount); + if (force_stats_snapshot_clear) + pgstat_clear_snapshot(); + if (pgstat_fetch_consistency == PGSTAT_FETCH_CONSISTENCY_SNAPSHOT) pgstat_build_snapshot(); else