Re: Update / Lock (and ShareLock) question

Augustin Amann <augustin(at)waw(dot)com> writes:
> Tom Lane a crit :
>> What that really means is that the first process is waiting for a row
>> lock that's held by the second one --- that is, it's trying to update a
>> row that the second transaction has updated and not yet committed.

> I understand. But a dead lock is for me, a situation that sould not
> appear, event if the storage is slow ... I'm wrong ?

If you're getting deadlocks on these, then what you have is two
concurrent transactions trying to update the same two tuples in
different orders. Which is a classic deadlock case, and the only
fix is to fix your app so that multiple updates are done in some
consistent order --- or broken into multiple transactions.

regards, tom lane