From 5a1e1d83022b976ebdec5cfa8f255c4278b75b8e Mon Sep 17 00:00:00 2001 From: Andres Freund Date: Mon, 21 Jun 2021 05:13:46 -0700 Subject: [PATCH] Use correct horizon when vacuuming catalog relations. In dc7420c2c92 I (Andres) accidentally used RelationIsAccessibleInLogicalDecoding() as the sole condition to use the non-shared catalog horizon in GetOldestNonRemovableTransactionId(). That is incorrect, as RelationIsAccessibleInLogicalDecoding() checks whether wal_level is logical. The correct check, as done e.g. in GlobalVisTestFor(), is to check IsCatalogRelation() and RelationIsAccessibleInLogicalDecoding(). The observed misbehavior of this bug was that there could be an endless loop in lazy_scan_prune(), because the horizons used in heap_page_prune() and the individual tuple liveliness checks did not match. Likely there are other potential consequences as well. A later commit will unify the determination which horizon has to be used, and add additional assertions to make it easier to catch a bug like this. Reported-By: Justin Pryzby Diagnosed-By: Matthias van de Meent Author: Matthias van de Meent Discussion: https://postgr.es/m/CAEze2Wg32Y9+WJfw=aofkRx1ZRFt_Ev6bNPc4PSaz7PjSFtZgQ@mail.gmail.com --- src/backend/storage/ipc/procarray.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/src/backend/storage/ipc/procarray.c b/src/backend/storage/ipc/procarray.c index 085bd1e407..e4c008e443 100644 --- a/src/backend/storage/ipc/procarray.c +++ b/src/backend/storage/ipc/procarray.c @@ -1971,9 +1971,10 @@ GetOldestNonRemovableTransactionId(Relation rel) ComputeXidHorizons(&horizons); /* select horizon appropriate for relation */ - if (rel == NULL || rel->rd_rel->relisshared) + if (rel == NULL || rel->rd_rel->relisshared || RecoveryInProgress()) return horizons.shared_oldest_nonremovable; - else if (RelationIsAccessibleInLogicalDecoding(rel)) + else if (IsCatalogRelation(rel) || + RelationIsAccessibleInLogicalDecoding(rel)) return horizons.catalog_oldest_nonremovable; else if (RELATION_IS_LOCAL(rel)) return horizons.temp_oldest_nonremovable;