X-Original-To: pgsql-performance-postgresql.org@postgresql.org Received: from localhost (mx1.hub.org [200.46.208.251]) by postgresql.org (Postfix) with ESMTP id 7562B9FA5E9 for ; Thu, 15 Jun 2006 01:31:26 -0300 (ADT) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.208.251]) (amavisd-new, port 10024) with ESMTP id 44021-02 for ; Thu, 15 Jun 2006 01:31:17 -0300 (ADT) X-Greylist: from auto-whitelisted by SQLgrey- Received: from linux.dunaweb.hu (linux.dunaweb.hu [62.77.196.1]) by postgresql.org (Postfix) with ESMTP id DFCF19FA4A6 for ; Thu, 15 Jun 2006 01:31:16 -0300 (ADT) Received: from localhost (linux.dunaweb.hu [127.0.0.1]) by linux.dunaweb.hu (Postfix) with ESMTP id 057D68E097A; Thu, 15 Jun 2006 06:31:15 +0200 (CEST) Received: from linux.dunaweb.hu ([127.0.0.1]) by localhost (linux.dunaweb.hu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 28101-05; Thu, 15 Jun 2006 06:31:14 +0200 (CEST) Received: from [81.17.177.202] (host-81-17-177-202.dunaweb.hu [81.17.177.202]) by linux.dunaweb.hu (Postfix) with ESMTP id F1EB18E0955; Thu, 15 Jun 2006 06:31:10 +0200 (CEST) Message-ID: <4490E286.90004@dunaweb.hu> Date: Thu, 15 Jun 2006 06:31:02 +0200 From: Zoltan Boszormenyi User-Agent: Thunderbird 1.5.0.2 (X11/20060501) MIME-Version: 1.0 To: "Jim C. Nasby" Cc: Volkan YAZICI , pgsql-performance@postgresql.org Subject: Re: Precomputed constants? 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> In-Reply-To: <20060614151804.GB34196@pervasive.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 8bit X-Virus-Scanned: amavisd-new at dunaweb.hu X-Virus-Scanned: Maia Mailguard 1.0.1 X-Archive-Number: 200606/285 X-Sequence-Number: 19642 Jim C. Nasby írta: > 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. Best regards, Zoltán Böszörményi