Re: Transaction-scope advisory locks

On Tue, Dec 14, 2010 at 9:51 AM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> Merlin Moncure <mmoncure@gmail.com> writes:
>> Not that I'm necessarily against the proposal, but what does this do
>> that can't already be done by locking a table or a table's row?
>
> I agree with Andres' point about this: sometimes it'd be more convenient
> for an advisory lock to be released automatically at transaction end.
> If you have a mix of clients that want that behavior with others that
> want a persistent hold on the same locks, you can't do it with regular
> locks.

right, plus 4:

automatic lock release on error.  right now if I'm grabbing
in-transaction lock inside a function, I have to put in sub
transaction handler to guarantee release if anything non trivial
happens mid lock.

merlin