diff options
Diffstat (limited to 'src/backend/access/transam/xact.c')
| -rw-r--r-- | src/backend/access/transam/xact.c | 26 |
1 files changed, 8 insertions, 18 deletions
diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 54f1058da31..12854dfad84 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -1247,24 +1247,14 @@ RecordTransactionCommit(void) /* * Transactions without an assigned xid can contain invalidation - * messages. While inplace updates do this, this is not known to be - * necessary; see comment at inplace CacheInvalidateHeapTuple(). - * Extensions might still rely on this capability, and standbys may - * need to process those invals. We can't emit a commit record - * without an xid, and we don't want to force assigning an xid, - * because that'd be problematic for e.g. vacuum. Hence we emit a - * bespoke record for the invalidations. We don't want to use that in - * case a commit record is emitted, so they happen synchronously with - * commits (besides not wanting to emit more WAL records). - * - * XXX Every known use of this capability is a defect. Since an XID - * isn't controlling visibility of the change that prompted invals, - * other sessions need the inval even if this transactions aborts. - * - * ON COMMIT DELETE ROWS does a nontransactional index_build(), which - * queues a relcache inval, including in transactions without an xid - * that had read the (empty) table. Standbys don't need any ON COMMIT - * DELETE ROWS invals, but we've not done the work to withhold them. + * messages (e.g. explicit relcache invalidations or catcache + * invalidations for inplace updates); standbys need to process those. + * We can't emit a commit record without an xid, and we don't want to + * force assigning an xid, because that'd be problematic for e.g. + * vacuum. Hence we emit a bespoke record for the invalidations. We + * don't want to use that in case a commit record is emitted, so they + * happen synchronously with commits (besides not wanting to emit more + * WAL records). */ if (nmsgs != 0) { |