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| author | Noah Misch <noah@leadboat.com> | 2024-06-27 19:21:05 -0700 |
|---|---|---|
| committer | Noah Misch <noah@leadboat.com> | 2024-06-27 19:21:12 -0700 |
| commit | b899cde0b86acfeb6310489ab6c478059075a8f4 (patch) | |
| tree | 098d9388b3dfff560dd75dc3c5c8c9b1cee56596 /src/backend | |
| parent | 1a6d65b64e8495280862f5757062eb844d134488 (diff) | |
| download | postgresql-b899cde0b86acfeb6310489ab6c478059075a8f4.tar.gz postgresql-b899cde0b86acfeb6310489ab6c478059075a8f4.zip | |
AccessExclusiveLock new relations just after assigning the OID.
This has no user-visible, important consequences, since other sessions'
catalog scans can't find the relation until we commit. However, this
unblocks introducing a rule about locks required to heap_update() a
pg_class row. CREATE TABLE has been acquiring this lock eventually, but
it can heap_update() pg_class.relchecks earlier. create_toast_table()
has been acquiring only ShareLock. Back-patch to v12 (all supported
versions), the plan for the commit relying on the new rule.
Reviewed (in an earlier version) by Robert Haas.
Discussion: https://postgr.es/m/20240611024525.9f.nmisch@google.com
Diffstat (limited to 'src/backend')
| -rw-r--r-- | src/backend/catalog/heap.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/src/backend/catalog/heap.c b/src/backend/catalog/heap.c index 6628ac1009b..987b53ba19d 100644 --- a/src/backend/catalog/heap.c +++ b/src/backend/catalog/heap.c @@ -1227,6 +1227,13 @@ heap_create_with_catalog(const char *relname, } /* + * Other sessions' catalog scans can't find this until we commit. Hence, + * it doesn't hurt to hold AccessExclusiveLock. Do it here so callers + * can't accidentally vary in their lock mode or acquisition timing. + */ + LockRelationOid(relid, AccessExclusiveLock); + + /* * Determine the relation's initial permissions. */ if (use_user_acl) |