As Tom mentioned, it sounds like you're being bitten by the oom killer. If, for some reason, you cannot run with it turned off, then add a really big swap space so it delays the onset of sudden death by oom to something really big.
Is It possible your work_mem is set too high? -- Sent via pgsql-admin mailing list (pgsql-admin@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-admin
