| From: | Richard Huxton <dev(at)archonet(dot)com> |
|---|---|
| To: | Gary Stainburn <gary(dot)stainburn(at)ringways(dot)co(dot)uk> |
| Cc: | pgsql-sql(at)postgresql(dot)org |
| Subject: | Re: Speed up slow select - was gone blind |
| Date: | 2005-04-01 13:00:46 |
| Message-ID: | 424D45FE.3010808@archonet.com |
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| Thread: | |
| Lists: | pgsql-sql |
Gary Stainburn wrote:
> Hi folks.
>
> I've got my select working now, but I haven't received the speed
> increase I'd expected. It replaced an earlier select which combined a
> single explicit join with multiple froms.
>
> The first select is the old one, the second one is the new one (with a
> new join). The new one takes 24 seconds to run while the old one took
> 29.
>
> How can I redo the select to improve the speed, or what else can I do to
> optimaise the database?
You'll want to compare the output of EXPLAIN ANALYSE for each version.
Post them here, or on the performance list.
Also, make sure your basic PG tuning is ok.
http://www.powerpostgresql.com/PerfList
--
Richard Huxton
Archonet Ltd
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