diff options
| author | Noah Misch <noah@leadboat.com> | 2024-09-24 15:25:18 -0700 |
|---|---|---|
| committer | Noah Misch <noah@leadboat.com> | 2024-09-24 15:25:23 -0700 |
| commit | 5c837f8fa022ff9d9ebced71fdcae273fe433570 (patch) | |
| tree | 95a912c65ea37cc8fab2ecab83619ba7575df11c /src/include/nodes/execnodes.h | |
| parent | 8590c942c1a6b861d0cf4fa5aa694ab3a65fa306 (diff) | |
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/include/nodes/execnodes.h')
| -rw-r--r-- | src/include/nodes/execnodes.h | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h index 8b4d38257fb..a1a6a564f19 100644 --- a/src/include/nodes/execnodes.h +++ b/src/include/nodes/execnodes.h @@ -556,6 +556,9 @@ typedef struct ResultRelInfo * one of its ancestors; see ExecCrossPartitionUpdateForeignKey(). */ List *ri_ancestorResultRels; + + /* updates do LockTuple() before oldtup read; see README.tuplock */ + bool ri_needLockTagTuple; } ResultRelInfo; /* |