Re: Waiting on a transaction

Wow, non-blocking lock failure?

Can I take this chance to say an overdue thanks to the Postgresql
developers? A truly commercial grade feature set in a free
database...

On 8/16/05, Matt Miller <mattm(at)epx(dot)com> wrote:
> On Tue, 2005-08-16 at 12:01 -0700, Bill Moseley wrote:
> > I wondered if my application should set an alarm and timeout
> > with an error if, by odd chance, an update hangs.
>
> Here's a way to handle this under the upcoming 8.1 release:
>
> Before you execute the update you can execute SELECT ... FOR UPDATE
> NOWAIT to select anything (e.g. dummy constant) from the row that you
> want to update. If no error is thrown then you have a lock on your row
> and you can confidently proceed with your update. Otherwise someone has
> that row locked. At that point you can loop and retry if you want.
>
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