"Pavan Deolasee" <[EMAIL PROTECTED]> writes: > On Wed, Mar 12, 2008 at 9:27 PM, Tom Lane <[EMAIL PROTECTED]> wrote: >> and it would have problems with a slow transaction >> generating a sparse set of subtransaction XIDs.
> I agree thats the worst case. But is that common ? Thats what I > was thinking when I proposed the alternate solution. I thought that can > happen only if most of the subtransactions abort, which again I thought > is not a normal case. No, I was thinking of the case where other sessions are chewing up XIDs while the lots-of-subtransactions transaction runs. If it's slow enough, there could be very large gaps between the XIDs it acquires for its subtransactions. So you'd have a situation where the exact same transaction processing might or might not run out of memory depending on what else happened meanwhile. Not a very pleasant property. regards, tom lane -- Sent via pgsql-patches mailing list (email@example.com) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-patches