Re: help optimizing query

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От Scott Marlowe
Тема Re: help optimizing query
Дата
Msg-id dcc563d10802092242v7309c860he337f4dcd4476927@mail.gmail.com
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Ответ на help optimizing query  (rihad <rihad@mail.ru>)
Список pgsql-general
On Feb 9, 2008 8:04 PM, Adam Rich <adam.r@sbcglobal.net> wrote:
> > It seems to do the job, but how good is it in the long run? Any way I
> > could tweak it?
>
>
> I think this form will work the best:
>
>
> SELECT u.login, MAX(s.stop_time) AS last_use_time
> FROM users u, stats s
> WHERE u.id=s.user_id
> AND u.status='3' AND u.next_plan_id IS NULL

If only ba small number of fields have next_plan as null, an they
correlate to the status normally, then an index on state where
next_plan_id is null might help here.

> GROUP BY u.login
> HAVING MAX(s.stop_time) < (now() - interval '1 month')
> ORDER BY last_use_time;

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