On Sun, Jan 10, 2010 at 9:04 AM, Jeremy Harris <jgh@xxxxxxxxxxx> wrote: > On 01/10/2010 12:28 PM, Mathieu De Zutter wrote: >> >> Sort (cost=481763.31..485634.61 rows=1548520 width=338) (actual >> time=5423.628..6286.148 rows=1551923 loops=1) >> Sort Key: event_timestamp > > > Sort Method: external merge Disk: 90488kB >> >> -> Seq Scan on log_event (cost=0.00..79085.92 rows=1548520 width=338) >> (actual time=0.022..2195.527 rows=1551923 loops=1) >> Filter: (event_timestamp > (now() - '1 year'::interval)) >> Total runtime: 6407.377 ms > > Needing to use an external (on-disk) sort method, when taking > only 90MB, looks odd. > > - Jeremy Well, you'd need to have work_mem > 90 MB for that not to happen, and very few people can afford to set that setting that high. If you have a query with three or four sorts using 90 MB a piece, and five or ten users running them, you can quickly kill the box... ...Robert -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
