On Fri, Oct 2, 2009 at 1:39 PM, Robert Haas <robertmhaas@xxxxxxxxx> wrote: > On Fri, Oct 2, 2009 at 9:54 AM, Merlin Moncure <mmoncure@xxxxxxxxx> wrote: >> it is ridiculous. your problem is almost definitely dead rows. I >> can't recall (and I can't find the info anywhere) if the 'hot' feature >> requires an index to be active -- I think it does. If so, creating a >> dummy field and indexing it should resolve the problem. Can you >> confirm the dead row issue by doing vacuum verbose and create the >> index? please respond with your results, I'm curious. Also, is >> autovacuum on? Have you measured iowait? > > Since he's updating all the fields in the table, an index will > certainly ensure that HOT does not apply, no? you're right...I missed that he put an index on value5 (why?). That's what's killing him. merlin -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance