From: Heikki Linnakangas Date: Mon, 21 Oct 2024 11:28:43 +0000 (+0300) Subject: Update outdated comment on WAL-logged locks with invalid XID X-Git-Tag: REL_18_BETA1~1668 X-Git-Url: http://git.postgresql.org/gitweb/?a=commitdiff_plain;h=3c7d78427ea9d92d346ee9aada4fa483bd1059e8;p=postgresql.git Update outdated comment on WAL-logged locks with invalid XID We haven't generated those for a long time. Discussion: https://www.postgresql.org/message-id/b439edfc-c5e5-43a9-802d-4cb51ec20646@iki.fi --- diff --git a/src/backend/storage/ipc/standby.c b/src/backend/storage/ipc/standby.c index 872679ca447..25267f0f85d 100644 --- a/src/backend/storage/ipc/standby.c +++ b/src/backend/storage/ipc/standby.c @@ -1121,6 +1121,9 @@ StandbyReleaseAllLocks(void) * StandbyReleaseOldLocks * Release standby locks held by top-level XIDs that aren't running, * as long as they're not prepared transactions. + * + * This is needed to prune the locks of crashed transactions, which didn't + * write an ABORT/COMMIT record. */ void StandbyReleaseOldLocks(TransactionId oldxid) @@ -1266,13 +1269,6 @@ standby_redo(XLogReaderState *record) * transactions already committed, since those commits raced ahead when * making WAL entries. * - * The loose timing also means that locks may be recorded that have a - * zero xid, since xids are removed from procs before locks are removed. - * So we must prune the lock list down to ensure we hold locks only for - * currently running xids, performed by StandbyReleaseOldLocks(). - * Zero xids should no longer be possible, but we may be replaying WAL - * from a time when they were possible. - * * For logical decoding only the running xacts information is needed; * there's no need to look at the locking information, but it's logged anyway, * as there's no independent knob to just enable logical decoding. For