Message-ID: <48C8E507.1090100@gmx.net>
Date: Thu, 11 Sep 2008 12:29:43 +0300
From: Peter Eisentraut <peter_e@gmx.net>
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To: Axel Rau <Axel.Rau@chaos1.de>
CC: PostgreSQL Performance <pgsql-performance@postgresql.org>
Subject: Re: performance impact of non-C locale
References: <47B44B1F-2DE2-4E7F-97C6-1599510AD8F1@Chaos1.DE>
In-Reply-To: <47B44B1F-2DE2-4E7F-97C6-1599510AD8F1@Chaos1.DE>
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Axel Rau wrote:
> some erp software requires a change of my pgsql cluster from
>     locale C        encoding UTF-8
> to
>     locale de_DE.UTF-8    encoding UTF-8
> 
> Most of my databases have only ASCII text data (8 bit UTF8 code range) 
> in the text columns.
> Does the above change influence index performance on such columns?

Yes.

> Does postmaster keep track on any multibyte characters being inserted in 
> such columns, so that the planner can adapt?

No.

> What other performance impacts can be expected?

The performance impact is mainly with string comparisons and sorts.  I 
suggest you run your own tests to find out what is acceptable in your 
scenario.