From: Jim C. Nasby <jnasby@pervasive.com>
To: Andrus <eetasoft@online.ee>
Cc: pgsql-performance@postgresql.org
Subject: Re: Query runs 38 seconds for small database!
Date: Mon, 8 May 2006 12:46:04 -0500
Message-ID: <20060508174604.GX99570@pervasive.com> (raw)
In-Reply-To: <e3nvmo$181j$1@news.hub.org>
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<20060508172816.GU99570@pervasive.com>
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On Mon, May 08, 2006 at 08:36:42PM +0300, Andrus wrote:
> > BTW, you might want to cut all the autovac thresholds in half; that's
> > what I typically do.
>
> I added ANALYZE command to my procedure which creates and loads data to
> postgres database
> from other DBMS. This runs only onvce after installing my application. I
> hope this is sufficient.
> If default threshold is so conservative values I expect there is some reason
> for it.
The only reason for being so conservative that I'm aware of was that it
was a best guess. Everyone I've talked to cuts the defaults down by at
least a factor of 2, sometimes even more.
BTW, these parameters are already tweaked from what we started with in
contrib/pg_autovacuum. It would allow a table to grow to 2x larger than
it should be before vacuuming, as opposed to the 40% that the current
settings allow. But even there, is there any real reason you want to
have 40% bloat? To make matters worse, those settings ensure that all
but the smallest databases will suffer runaway bloat unless you bump up
the FSM settings.
--
Jim C. Nasby, Sr. Engineering Consultant jnasby@pervasive.com
Pervasive Software http://pervasive.com work: 512-231-6117
vcard: http://jim.nasby.net/pervasive.vcf cell: 512-569-9461
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To: pgsql-performance@postgresql.org
Cc: jnasby@pervasive.com, eetasoft@online.ee
Subject: Re: Query runs 38 seconds for small database!
In-Reply-To: <20060508174604.GX99570@pervasive.com>
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