postgres.git / summary / log / commit / refs

commit    5a1e1d83022b976ebdec5cfa8f255c4278b75b8e
Author:   Andres Freund <andres@anarazel.de>
Date:     Mon Jun 21 12:13:46 2021 +0000

    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 <pryzby@telsasoft.com>
    Diagnosed-By: Matthias van de Meent <boekewurm+postgres@gmail.com>
    Author: Matthias van de Meent <boekewurm+postgres@gmail.com>
    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 085bd1e4077..e4c008e443f 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;


[parent: 8d29d45d9b3c]