From: Jim C. Nasby <jnasby@pervasive.com>
To: Zoltan Boszormenyi <zboszor@dunaweb.hu>
Cc: Volkan YAZICI <yazicivo@ttnet.net.tr>
Cc: pgsql-performance@postgresql.org
Subject: Re: Precomputed constants?
Date: Thu, 15 Jun 2006 10:59:29 -0500
Message-ID: <20060615155929.GL34196@pervasive.com> (raw)
In-Reply-To: <4490E286.90004@dunaweb.hu>
References: <3167.213.163.11.81.1150282434.squirrel@www.dunaweb.hu>
<20060614110713.GA2277@alamut.tdm.local>
<3861.213.163.11.81.1150284610.squirrel@www.dunaweb.hu>
<20060614151804.GB34196@pervasive.com>
<4490E286.90004@dunaweb.hu>
On Thu, Jun 15, 2006 at 06:31:02AM +0200, Zoltan Boszormenyi wrote:
> Jim C. Nasby ?rta:
> >On Wed, Jun 14, 2006 at 01:30:10PM +0200, B?sz?rm?nyi Zolt?n wrote:
> >
> >>Replacing random() with a true constant gives me index scan
> >>even if it's hidden inside other function calls. E.g.:
> >>
> >
> >The database has no choice but to compute random() for every row; it's
> >marked VOLATILE.
> >
>
> I see now, docs about CREATE FUNCTION mentions random(),
> currval() and timeofday() as examples for VOLATILE.
> But where in the documentation can I find this info about all
> built-in functions? Thanks.
No, but you can query pg_proc for that info. The docs should have info
about that table.
--
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, zboszor@dunaweb.hu, yazicivo@ttnet.net.tr
Subject: Re: Precomputed constants?
In-Reply-To: <20060615155929.GL34196@pervasive.com>
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