Re: [HACKERS] It sorta works, but I'm confused about locking

Massimo Dal Zotto <dz(at)cs(dot)unitn(dot)it> writes:
>> it's not at all clear whether I should call RelationUnsetLockForWrite
>> at the end of the routine or not; some existing code does, some doesn't.

> It is not done where there is an immediate CommitTransactionCommand which
> already releases the locks.

Hmm. OK, but I guess I don't really understand why it's ever valid to
release a lock before the end of the transaction --- and
CommitTransactionCommand isn't necessarily the end of the transaction
anyway, if you're inside a transaction block.

Basically: it seems to me it's a bug to call UnsetLock (any flavor)
from *anywhere* except transaction commit. If this is not so, why not?

regards, tom lane