diff options
| author | Heikki Linnakangas <heikki.linnakangas@iki.fi> | 2024-12-21 23:42:39 +0200 |
|---|---|---|
| committer | Heikki Linnakangas <heikki.linnakangas@iki.fi> | 2024-12-21 23:45:56 +0200 |
| commit | 9c1afd3447ffee157422564280df87e59a164476 (patch) | |
| tree | e49cd1b78fdd310674595de0031337be1fb724c0 /src | |
| parent | 2280912165d62a8b1de477818a405a76ffc66b2e (diff) | |
Update TransactionXmin when MyProc->xmin is updated
GetSnapshotData() set TransactionXmin = MyProc->xmin, but when
SnapshotResetXmin() advanced MyProc->xmin, it did not advance
TransactionXmin correspondingly. That meant that TransactionXmin could
be older than MyProc->xmin, and XIDs between than TransactionXmin and
the real MyProc->xmin could be vacuumed away. One known consequence is
in pg_subtrans lookups: we might try to look up the status of an XID
that was already truncated away.
Back-patch to all supported versions.
Reviewed-by: Andres Freund
Discussion: https://www.postgresql.org/message-id/d27a046d-a1e4-47d1-a95c-fbabe41debb4@iki.fi
Diffstat (limited to 'src')
| -rw-r--r-- | src/backend/utils/time/snapmgr.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/src/backend/utils/time/snapmgr.c b/src/backend/utils/time/snapmgr.c index 85b5d5cdb9e..dc13b231de5 100644 --- a/src/backend/utils/time/snapmgr.c +++ b/src/backend/utils/time/snapmgr.c @@ -1045,7 +1045,7 @@ SnapshotResetXmin(void) if (pairingheap_is_empty(&RegisteredSnapshots)) { - MyPgXact->xmin = InvalidTransactionId; + MyPgXact->xmin = TransactionXmin = InvalidTransactionId; return; } @@ -1053,7 +1053,7 @@ SnapshotResetXmin(void) pairingheap_first(&RegisteredSnapshots)); if (TransactionIdPrecedes(MyPgXact->xmin, minSnapshot->xmin)) - MyPgXact->xmin = minSnapshot->xmin; + MyPgXact->xmin = TransactionXmin = minSnapshot->xmin; } /* |