Received: from malur.postgresql.org ([217.196.149.56])
	by arkaria.postgresql.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256)
	(Exim 4.89)
	(envelope-from <pgsql-performance-owner+archive@lists.postgresql.org>)
	id 1hAuaW-0003zT-CH
	for pgsql-performance@arkaria.postgresql.org; Mon, 01 Apr 2019 10:54:48 +0000
Received: from localhost ([127.0.0.1] helo=malur.postgresql.org)
	by malur.postgresql.org with esmtp (Exim 4.89)
	(envelope-from <pgsql-performance-owner+archive@lists.postgresql.org>)
	id 1hAuaU-0000Mu-AA
	for pgsql-performance@arkaria.postgresql.org; Mon, 01 Apr 2019 10:54:46 +0000
Received: from makus.postgresql.org ([2001:4800:3e1:1::229])
	by malur.postgresql.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256)
	(Exim 4.89)
	(envelope-from <cb@df7cb.de>)
	id 1hAuaT-0000Mm-Ud
	for pgsql-performance@lists.postgresql.org; Mon, 01 Apr 2019 10:54:46 +0000
Received: from feynman.df7cb.de ([195.49.152.168])
	by makus.postgresql.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256)
	(Exim 4.89)
	(envelope-from <cb@df7cb.de>)
	id 1hAuaM-0000GD-4h
	for pgsql-performance@lists.postgresql.org; Mon, 01 Apr 2019 10:54:44 +0000
Received: from msg.df7cb.de (unknown
 [IPv6:2003:5b:203b:100:7627:eaff:fe52:8e03])
	(using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits))
	(Client did not present a certificate)
	by feynman.df7cb.de (Postfix) with ESMTPSA id 44Xq3b34Z8z3F0x;
	Mon,  1 Apr 2019 12:54:35 +0200 (CEST)
Date: Mon, 1 Apr 2019 12:54:35 +0200
From: Christoph Berg <myon@debian.org>
To: Gavin Flower <GavinFlower@archidevsys.co.nz>
Cc: pgsql-performance@lists.postgresql.org
Subject: Re: Postgresql Sort cost Poor performance?
Message-ID: <20190401105435.GD13726@msg.df7cb.de>
References: <1554111914781-0.post@n3.nabble.com>
 <87d0m6uj5u.fsf@news-spur.riddles.org.uk>
 <3113f2f4-a4da-4862-8596-2e189398c988@archidevsys.co.nz>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <3113f2f4-a4da-4862-8596-2e189398c988@archidevsys.co.nz>
User-Agent: Mutt/1.10.1 (2018-07-13)
List-Id: <pgsql-performance.lists.postgresql.org>
List-Help: <https://lists.postgresql.org/manage/>
List-Subscribe: <https://lists.postgresql.org/manage/>
List-Post: <mailto:pgsql-performance@lists.postgresql.org>
List-Owner: <mailto:pgsql-performance-owner@lists.postgresql.org>
List-Archive: <https://www.postgresql.org/list/pgsql-performance>
Precedence: bulk

Re: Gavin Flower 2019-04-01 <3113f2f4-a4da-4862-8596-2e189398c988@archidevsys.co.nz>
> Would it be possible to optionally enable the system to create a hidden
> system column for the text field to be sorted, the new column would be the
> original column preprocessed to sort correctly & efficiently.

That's the idea behind the strxfrm(3) optimization that ultimately got
disabled again for non-C locales because glibc fails to implement it
correctly.

Christoph