diff options
| author | Michael P | 2011-07-14 04:56:00 +0000 |
|---|---|---|
| committer | Michael P | 2011-07-14 04:56:00 +0000 |
| commit | fb2a3a864dee367f2cfe76a3a4fff5e02cb94fc1 (patch) | |
| tree | ca7f3807510fde2895da757f3bf72986fd009f6e /src/backend | |
| parent | f0f4ae5fddf646b1a41dd4d512fccdf9c9587254 (diff) | |
Performance issue with snapshot processing
This commit solves an issue with snapshot processing in the case
where cluster was used under multiple Coordinators.
When a Coordinator/Coordinator connection was initialized,
backend coordinator initialized a transaction to GTM that was never
committed. A consequence of that was Snapshot xmin that remained
to a constant value. Another consequence was recent global Xmin
value set to a lower value, making autovacuum having absolutely no effects.
This fix improves performance of the whole cluster by making autovacuum
remove correctly old tuples for long-period runs.
Diffstat (limited to 'src/backend')
| -rw-r--r-- | src/backend/access/transam/varsup.c | 3 | ||||
| -rw-r--r-- | src/backend/storage/ipc/procarray.c | 3 |
2 files changed, 4 insertions, 2 deletions
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index a5ff7537b3..1c684f5dfc 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -203,7 +203,8 @@ GetNewTransactionId(bool isSubXact) increment_xid = false; elog(DEBUG1, "xid (%d) does not follow ShmemVariableCache->nextXid (%d)", xid, ShmemVariableCache->nextXid); - } else + } + else ShmemVariableCache->nextXid = xid; } else diff --git a/src/backend/storage/ipc/procarray.c b/src/backend/storage/ipc/procarray.c index 2de6db4511..5477df663b 100644 --- a/src/backend/storage/ipc/procarray.c +++ b/src/backend/storage/ipc/procarray.c @@ -1234,7 +1234,8 @@ GetSnapshotData(Snapshot snapshot) if (GetSnapshotDataDataNode(snapshot)) return snapshot; /* else fallthrough */ - } else if (IS_PGXC_COORDINATOR && !IsConnFromCoord()) + } + else if (IS_PGXC_COORDINATOR && !IsConnFromCoord() && IsNormalProcessingMode()) { /* Snapshot has ever been received from remote Coordinator */ if (GetSnapshotDataCoordinator(snapshot)) |