From 4abf411e2328f57fd2547b5c2187a2159e97a606 Mon Sep 17 00:00:00 2001 From: Melanie Plageman Date: Wed, 24 Jun 2026 14:51:31 -0400 Subject: [PATCH] pg_stat_io: Don't flag extends by autovacuum launcher pg_stat_io asserts on unexpected combinations of backend type and IOOp. These combinations were meant to help detect bugs given our current understanding of the system -- not serve as a set of rules for what is allowed. The autovacuum launcher scans catalog tables and may on-access prune them. This previously wouldn't have led to any extends of the relation, but now that on-access pruning may pin a page of the visibility map (4f7ecca84ddacbce27), scanning tables may lead to extending the visibility map. This would cause the launcher to trip an assert. Since there is no reason to forbid the launcher from doing extends, remove it from the list of backend type pgstat_tracks_io_op flags for doing IOOP_EXTEND. Read-only catalog scans still don't let pruning set the VM; doing so needs table AM API changes and is left for the future. Reported-by: Ewan Young Discussion: https://postgr.es/m/CAON2xHNOyaN9MCZohhD_NL6as3QVhGA0SOn2Hyi9w6+Y-_1bFA@mail.gmail.com --- src/backend/utils/activity/pgstat_io.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/src/backend/utils/activity/pgstat_io.c b/src/backend/utils/activity/pgstat_io.c index 13a5d8e6440..38bae7b15d2 100644 --- a/src/backend/utils/activity/pgstat_io.c +++ b/src/backend/utils/activity/pgstat_io.c @@ -497,8 +497,8 @@ pgstat_tracks_io_op(BackendType bktype, IOObject io_object, (io_op == IOOP_EVICT || io_op == IOOP_HIT))) return false; - if ((bktype == B_AUTOVAC_LAUNCHER || bktype == B_BG_WRITER || - bktype == B_CHECKPOINTER) && io_op == IOOP_EXTEND) + if ((bktype == B_BG_WRITER || bktype == B_CHECKPOINTER) && + io_op == IOOP_EXTEND) return false; /*