On 22 Feb 2010, at 19:35, Yang Zhang wrote: > I also wouldn't have imagined an external merge-sort as being very Where's that external merge-sort coming from? Can you show an explain analyze? If your work-mem is too low there's a good chance that Postgres has to use your disks for sorting, which will obviously be quite slow. Alban Hertroys -- If you can't see the forest for the trees, cut the trees and you'll see there is no forest. !DSPAM:737,4b82d18510442035320951! -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
