| From: | "Joshua D(dot) Drake" <jd(at)commandprompt(dot)com> |
|---|---|
| To: | Ogden <lists(at)darkstatic(dot)com> |
| Cc: | Jesper Krogh <jesper(at)krogh(dot)cc>, Kenneth Marshall <ktm(at)rice(dot)edu>, pgsql-performance(at)postgresql(dot)org |
| Subject: | Re: Query much faster with enable_seqscan=0 |
| Date: | 2010-09-21 19:07:11 |
| Message-ID: | 1285096031.15919.68.camel@jd-desktop.unknown.charter.com |
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| Thread: | |
| Lists: | pgsql-performance |
On Tue, 2010-09-21 at 14:02 -0500, Ogden wrote:
> How odd, I set the following:
>
> seq_page_cost = 1.0
> random_page_cost = 2.0
>
> And now the query runs in milliseconds as opposed to 14 seconds. Could this really be the change? I am running ANALYZE now - how often is it recommended to do this?
PostgreSQL's defaults are based on extremely small and some would say
(non production) size databases. As a matter of course I always
recommend bringing seq_page_cost and random_page_cost more in line.
However, you may want to try moving random_page_cost back to 4 and try
increasing cpu_tuple_cost instead.
Sincerely,
Joshua D. Drake
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