Hello >> >> I'm not understanding why it is sorting on disk if it would fit within >> a work_mem segment - by a fairly wide margin. Is there something else >> I can do to get that sort to happen in memory? >> Planner working with estimations. So there is some probability so planner expected a larger result set and used a external sort. Probably quick sort takes more memory too. Your statistic are probably out of range - system expecting 0.5 mil rec and get 2 mil rec. Regards Pavel -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance