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author | Noah Misch <noah@leadboat.com> | 2024-09-24 15:25:18 -0700 |
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committer | Noah Misch <noah@leadboat.com> | 2024-09-24 15:25:18 -0700 |
commit | aac2c9b4fde889d13f859c233c2523345e72d32b (patch) | |
tree | 65d5e1b73059d4c423dee459bcf58bc0c47b8a9a /src/include/nodes/execnodes.h | |
parent | a07e03fd8fa7daf4d1356f7cb501ffe784ea6257 (diff) | |
download | postgresql-aac2c9b4fde889d13f859c233c2523345e72d32b.tar.gz postgresql-aac2c9b4fde889d13f859c233c2523345e72d32b.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/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 88467977f89..aab59d681cf 100644 --- a/src/include/nodes/execnodes.h +++ b/src/include/nodes/execnodes.h @@ -485,6 +485,9 @@ typedef struct ResultRelInfo /* Have the projection and the slots above been initialized? */ bool ri_projectNewInfoValid; + /* updates do LockTuple() before oldtup read; see README.tuplock */ + bool ri_needLockTagTuple; + /* triggers to be fired, if any */ TriggerDesc *ri_TrigDesc; |