Re: Very poor performance

"Aaron Burnett" <aburnett@bzzagent.com> wrote:

> Postgres Version 8.25

Do you mean 8.2.5?  (There is no PostgreSQL version 8.25.)

If you're concerned about performance and you're still on 8.2, you
might want to consider updating to a new major version.

> 16 Gig RAM
> 192MB work_mem  (increasing to 400MB didn't change the outcome)

What other non-default settings do you have?

> explain analyze select distinct(id) from member  where id in
> (select memberid from answerselectinstance where   nswerid =
> 127443  OR answerid = 127444  OR  answerid = 127445  OR  answerid
> = 127446  OR  answerid = 127447  OR  answerid = 127448   ) ;

How does this do?:

explain analyze
select distinct(m.id)
  from answerselectinstance a
  join member m
    on m.id = a.memberid
  where a.answerid between 127443 and 127448
;

-Kevin