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| author | Tomas Vondra <tomas.vondra@postgresql.org> | 2023-02-22 15:24:09 +0100 |
|---|---|---|
| committer | Tomas Vondra <tomas.vondra@postgresql.org> | 2023-02-22 16:25:45 +0100 |
| commit | 8b9cbd42b61ff55e5519631bada5d310159e3a5f (patch) | |
| tree | 407843fdfe9fa116f03a7a5d04db1cc0a39488a7 /src/backend/replication/logical/reorderbuffer.c | |
| parent | 482ab3e4f9e0a2fcef96bdcbe7a719858fae8f79 (diff) | |
| download | postgresql-8b9cbd42b61ff55e5519631bada5d310159e3a5f.tar.gz postgresql-8b9cbd42b61ff55e5519631bada5d310159e3a5f.zip | |
Fix snapshot handling in logicalmsg_decode
Whe decoding a transactional logical message, logicalmsg_decode called
SnapBuildGetOrBuildSnapshot. But we may not have a consistent snapshot
yet at that point. We don't actually need the snapshot in this case
(during replay we'll have the snapshot from the transaction), so in
practice this is harmless. But in assert-enabled build this crashes.
Fixed by requesting the snapshot only in non-transactional case, where
we are guaranteed to have SNAPBUILD_CONSISTENT.
Backpatch to 11. The issue exists since 9.6.
Backpatch-through: 11
Reviewed-by: Andres Freund
Discussion: https://postgr.es/m/84d60912-6eab-9b84-5de3-41765a5449e8@enterprisedb.com
Diffstat (limited to 'src/backend/replication/logical/reorderbuffer.c')
| -rw-r--r-- | src/backend/replication/logical/reorderbuffer.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/src/backend/replication/logical/reorderbuffer.c b/src/backend/replication/logical/reorderbuffer.c index 709365fc8c6..721fa652d25 100644 --- a/src/backend/replication/logical/reorderbuffer.c +++ b/src/backend/replication/logical/reorderbuffer.c @@ -821,6 +821,13 @@ ReorderBufferQueueMessage(ReorderBuffer *rb, TransactionId xid, Assert(xid != InvalidTransactionId); + /* + * We don't expect snapshots for transactional changes - we'll use the + * snapshot derived later during apply (unless the change gets + * skipped). + */ + Assert(!snapshot); + oldcontext = MemoryContextSwitchTo(rb->context); change = ReorderBufferGetChange(rb); @@ -839,6 +846,9 @@ ReorderBufferQueueMessage(ReorderBuffer *rb, TransactionId xid, ReorderBufferTXN *txn = NULL; volatile Snapshot snapshot_now = snapshot; + /* Non-transactional changes require a valid snapshot. */ + Assert(snapshot_now); + if (xid != InvalidTransactionId) txn = ReorderBufferTXNByXid(rb, xid, true, NULL, lsn, true); |