Re: Inconsistent performance

On Mon, 15 Sep 2003, Joseph Bove wrote:

> Stephan,
>
> Actually, it's inconsistent with the exact same command. I've now
> replicated the problem by doing the following command:
>
> select count (*) from table;
>
> The table in question has 88899 rows.
>
> The response time is anywhere from 1 second to 12 seconds. Different
> response times can occur in the same minute of testing!

Well, that's really only got one valid plan right now (seqscan and
aggregate). It'd be mildly interesting to see what explain analyze says in
slow and fast states, although I'd be willing to bet that it's just going
to effectively show that the seqscan is taking more or less time.

I think we're going to need to see the configuration settings for the
server and possibly some info on how big the table is (say relpages for
the pg_class row associated with the table after a vacuum full).