On Fri, Oct 2, 2009 at 1:39 PM, Robert Haas <robertmhaas@gmail.com> wrote:
> On Fri, Oct 2, 2009 at 9:54 AM, Merlin Moncure <mmoncure@gmail.com> 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