From: Gábriel Ákos <akos.gabriel@i-logic.hu>
To: pgsql-performance@postgresql.org
Subject: Re: count(*) performance
Date: Mon, 27 Mar 2006 20:05:31 +0200
Message-ID: <4428296B.9040505@i-logic.hu> (raw)
In-Reply-To: <20060327134103.GI80726@pervasive.com>
References: <4427E9E8.9030806@i-logic.hu>
<20060327134103.GI80726@pervasive.com>
Jim C. Nasby wrote:
> But in this case, I'd bet money that if it's taking 4 minutes something
> else is wrong. Have you been vacuuming that table frequently enough?
That gave me an idea. I thought that autovacuum is doing it right, but I
issued a vacuum full analyze verbose , and it worked all the day.
After that I've tweaked memory settings a bit too (more fsm_pages)
Now:
staging=# SELECT count(*) from infx.infx_product;
count
---------
3284997
(1 row)
Time: 1301.049 ms
As I saw the output, the database was compressed to 10% of its size :)
This table has quite big changes every 4 hour, let's see how it works.
Maybe I'll have to issue full vacuums from cron regularly.
> What's SELECT relpages FROM pg_class WHERE relname='tablename' show?
This went to 10% as well, now it's around 156000 pages.
Regards,
Akos
--
Üdvözlettel,
Gábriel Ákos
-=E-Mail :akos.gabriel@i-logic.hu|Web: http://www.i-logic.hu=-
-=Tel/fax:+3612367353 |Mobil:+36209278894 =-
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To: pgsql-performance@postgresql.org
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Subject: Re: count(*) performance
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