| From: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
|---|---|
| To: | Oleg Lebedev <oleg(dot)lebedev(at)waterford(dot)org> |
| Cc: | "pgsql-performance(at)postgresql(dot)org" <pgsql-performance(at)postgresql(dot)org> |
| Subject: | Re: Slow query |
| Date: | 2003-03-24 22:08:50 |
| Message-ID: | 20749.1048543730@sss.pgh.pa.us |
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| Lists: | pgsql-performance |
Oleg Lebedev <oleg(dot)lebedev(at)waterford(dot)org> writes:
> I just ran the query you sent me and attached the output of EXPLAIN
> ANALYZE as TOMs_plan.txt
> It did not speed up the query significantly.
Nope. I was hoping to see a faster-start plan, but given the number of
rows involved I guess it won't change its mind. You're going to have to
think about a more intelligent approach, rather than minor tweaks.
One question: since objectid is evidently a primary key, why are you
doing a subselect for the first part? Wouldn't it give the same result
just to say "m.activity = '347667'" in the top-level WHERE?
As for the second part, I think you'll have to try to rewrite it as a
join with the media table.
regards, tom lane
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