From: Bill Moran <wmoran@collaborativefusion.com>
To: Alexander Staubo <alex@purefiction.net>
Cc: pgsql-performance@postgresql.org
Subject: Re: specific query (not all) on Pg8 MUCH slower than Pg7
Date: Tue, 8 May 2007 11:04:27 -0400
Message-ID: <20070508110427.c714d52f.wmoran@collaborativefusion.com> (raw)
In-Reply-To: <88daf38c0705080759o2e5771c3qdf1b34baa581fc53@mail.gmail.com>
References: <200705081418.l48EIY8V026360@larrys.harvard.edu>
<1160.1178635705@sss.pgh.pa.us>
<88daf38c0705080759o2e5771c3qdf1b34baa581fc53@mail.gmail.com>
In response to "Alexander Staubo" <alex@purefiction.net>:
> On 5/8/07, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> > You're not getting the indexscan optimization of the LIKE clause, which
> > is most likely due to having initdb'd the 8.1 installation in something
> > other than C locale. You can either redo the initdb in C locale (which
> > might be a good move to fix other inconsistencies from the 7.3 behavior
> > you're used to) or create a varchar_pattern_ops index on the column(s)
> > you're using LIKE with.
>
> Given the performance implications of setting the wrong locale, and
> the high probability of accidentally doing this (I run my shells with
> LANG=en_US.UTF-8, so all my databases have inherited this locale), why
> is there no support for changing the database locale after the fact?
>
> # alter database test set lc_collate = 'C';
> ERROR: parameter "lc_collate" cannot be changed
How would that command handle UTF data that could not be converted to C?
--
Bill Moran
Collaborative Fusion Inc.
http://people.collaborativefusion.com/~wmoran/
wmoran@collaborativefusion.com
Phone: 412-422-3463x4023
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To: pgsql-performance@postgresql.org
Cc: wmoran@collaborativefusion.com, alex@purefiction.net
Subject: Re: specific query (not all) on Pg8 MUCH slower than Pg7
In-Reply-To: <20070508110427.c714d52f.wmoran@collaborativefusion.com>
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