Re: updating a row in a table with only one row

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