Re: Review: Hot standby

+ /*
+ * Release locks, if any.
+ */
+ RelationReleaseRecoveryLocks(xlrec->slotId);

If I am reading the patch correctly, AccessExclusiveLocks acquired by a
transaction will be released when the transaction is committed or aborted.
If the transaction errors out with FATAL, the locks will be released when
the next transaction occupying the same slot is committed/aborted.

I smell some sort of deadlock condition here. What if the following events
happen:

- transaction A (slot 1) starts and acquires AEL lock on relation
- transaction A errors out with FATAL error
- transaction B (slot 1) starts and requests AEL lock on the same relation

Won't B deadlock with A ? Since B hasn't yet committed/aborted, the lock
held by A is not released and
relation_redo_lock() would indefinitely wait for the lock.

Thanks,
Pavan

--
Pavan Deolasee
EnterpriseDB http://www.enterprisedb.com