Received: from malur.postgresql.org ([217.196.149.56])
 by arkaria.postgresql.org with esmtp (Exim 4.80) (envelope-from
 <pgsql-performance-owner+M53710=pgsql-performance-ar@postgresql.org>)
 id 1a36FK-0004N0-9A
 for pgsql-performance@arkaria.postgresql.org; Sun, 29 Nov 2015 17:58:46 +0000
Received: from localhost ([127.0.0.1] helo=postgresql.org)
 by malur.postgresql.org with smtp (Exim 4.84) (envelope-from
 <pgsql-performance-owner+M53710=pgsql-performance-ar@postgresql.org>)
 id 1a36FJ-0004Iu-S6
 for pgsql-performance@arkaria.postgresql.org; Sun, 29 Nov 2015 17:58:45 +0000
Received: from makus.postgresql.org ([2001:4800:1501:1::229])
 by malur.postgresql.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA384:256)
 (Exim 4.84) (envelope-from <tgl@sss.pgh.pa.us>) id 1a36FJ-0004HL-Dw
 for pgsql-performance@postgresql.org; Sun, 29 Nov 2015 17:58:45 +0000
Received: from sss.pgh.pa.us ([66.207.139.130])
 by makus.postgresql.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA384:256)
 (Exim 4.84) (envelope-from <tgl@sss.pgh.pa.us>) id 1a36FH-0002g8-1s
 for pgsql-performance@postgresql.org; Sun, 29 Nov 2015 17:58:44 +0000
Received: from sss1.sss.pgh.pa.us (localhost [127.0.0.1])
 by sss.pgh.pa.us (8.14.4/8.14.4) with ESMTP id tATHwanM006980;
 Sun, 29 Nov 2015 12:58:36 -0500
From: Tom Lane <tgl@sss.pgh.pa.us>
To: "Peter J. Holzer" <hjp-pgsql@hjp.at>
cc: pgsql-performance@postgresql.org
Subject: Re: Query that took a lot of time in Postgresql when not using trim
 in order by
In-reply-to: <20151129132323.GA29654@hjp.at>
References: 
 <CANL=RnsS-VFKwV0-PGRZwvV6boFRZ9CSBGvDFDm3TLts-SUHVQ@mail.gmail.com>
 <5655E044.6070207@postgrespro.ru>
 <855510F3-CAF0-4C52-848E-54EC61F10DE6@gmail.com>
 <20151129132323.GA29654@hjp.at>
Comments: In-reply-to "Peter J. Holzer" <hjp-pgsql@hjp.at>
 message dated "Sun, 29 Nov 2015 14:23:23 +0100"
Date: Sun, 29 Nov 2015 12:58:36 -0500
Message-ID: <6979.1448819916@sss.pgh.pa.us>
X-Pg-Spam-Score: -1.9 (-)
List-Archive: <http://archives.postgresql.org/pgsql-performance>
List-Help: <mailto:majordomo@postgresql.org?body=help>
List-ID: <pgsql-performance.postgresql.org>
List-Owner: <mailto:pgsql-performance-owner@postgresql.org>
List-Post: <mailto:pgsql-performance@postgresql.org>
List-Subscribe: <mailto:majordomo@postgresql.org?body=sub%20pgsql-performance>
List-Unsubscribe: 
 <mailto:majordomo@postgresql.org?body=unsub%20pgsql-performance>
X-Mailing-List: pgsql-performance
Precedence: bulk
Sender: pgsql-performance-owner@postgresql.org

"Peter J. Holzer" <hjp-pgsql@hjp.at> writes:
> Seems plausible. Also I'm wondering what CPU this is: 36 seconds for an
> in-memory sort of 900k rows seems slow to me.

I'm wondering if it's textual data in some locale whose strcoll() behavior
is exceptionally slow.

			regards, tom lane


-- 
Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-performance