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authorNoah Misch <noah@leadboat.com>2024-09-24 15:25:18 -0700
committerNoah Misch <noah@leadboat.com>2024-09-24 15:25:23 -0700
commit5c837f8fa022ff9d9ebced71fdcae273fe433570 (patch)
tree95a912c65ea37cc8fab2ecab83619ba7575df11c /src/backend/executor/execReplication.c
parent8590c942c1a6b861d0cf4fa5aa694ab3a65fa306 (diff)
downloadpostgresql-5c837f8fa022ff9d9ebced71fdcae273fe433570.tar.gz
postgresql-5c837f8fa022ff9d9ebced71fdcae273fe433570.zip
For inplace update durability, make heap_update() callers wait.
The previous commit fixed some ways of losing an inplace update. It remained possible to lose one when a backend working toward a heap_update() copied a tuple into memory just before inplace update of that tuple. In catalogs eligible for inplace update, use LOCKTAG_TUPLE to govern admission to the steps of copying an old tuple, modifying it, and issuing heap_update(). This includes MERGE commands. To avoid changing most of the pg_class DDL, don't require LOCKTAG_TUPLE when holding a relation lock sufficient to exclude inplace updaters. Back-patch to v12 (all supported versions). In v13 and v12, "UPDATE pg_class" or "UPDATE pg_database" can still lose an inplace update. The v14+ UPDATE fix needs commit 86dc90056dfdbd9d1b891718d2e5614e3e432f35, and it wasn't worth reimplementing that fix without such infrastructure. Reviewed by Nitin Motiani and (in earlier versions) Heikki Linnakangas. Discussion: https://postgr.es/m/20231027214946.79.nmisch@google.com
Diffstat (limited to 'src/backend/executor/execReplication.c')
-rw-r--r--src/backend/executor/execReplication.c7
1 files changed, 6 insertions, 1 deletions
diff --git a/src/backend/executor/execReplication.c b/src/backend/executor/execReplication.c
index 125f1367d1a..3ecb7efe365 100644
--- a/src/backend/executor/execReplication.c
+++ b/src/backend/executor/execReplication.c
@@ -19,6 +19,7 @@
#include "access/tableam.h"
#include "access/transam.h"
#include "access/xact.h"
+#include "catalog/catalog.h"
#include "commands/trigger.h"
#include "executor/executor.h"
#include "executor/nodeModifyTable.h"
@@ -483,8 +484,12 @@ ExecSimpleRelationUpdate(ResultRelInfo *resultRelInfo,
Relation rel = resultRelInfo->ri_RelationDesc;
ItemPointer tid = &(searchslot->tts_tid);
- /* For now we support only tables. */
+ /*
+ * We support only non-system tables, with
+ * check_publication_add_relation() accountable.
+ */
Assert(rel->rd_rel->relkind == RELKIND_RELATION);
+ Assert(!IsCatalogRelation(rel));
CheckCmdReplicaIdentity(rel, CMD_UPDATE);