From: Samuel Gendler <sgendler@ideasculptor.com>
To: Pavel Stehule <pavel.stehule@gmail.com>
Cc: Peter Eisentraut <peter_e@gmx.net>
Cc: Eyal Wilde <eyal@impactsoft.co.il>
Cc: pgsql-sql@postgresql.org
Subject: Re: a strange order by behavior
Date: Wed, 22 Jun 2011 21:34:34 -0700
Message-ID: <BANLkTikCX59HXnvom_LQDT7eYf3OeCQMDg@mail.gmail.com> (raw)
In-Reply-To: <BANLkTimUpGu04LW4ohAjvyU6Kkpee_2Y6Q@mail.gmail.com>
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<BANLkTi=PXV+FrAJHHX56D41Xo4DzG7vADA@mail.gmail.com>
<BANLkTim9sFLt3e2+auF_oTr68UETiW83VA@mail.gmail.com>
<BANLkTi=7Lqyj4LbRPHp1mLo_0-mFN5XPmA@mail.gmail.com>
<1308773527.10498.7.camel@vanquo.pezone.net>
<BANLkTimUpGu04LW4ohAjvyU6Kkpee_2Y6Q@mail.gmail.com>
On Wed, Jun 22, 2011 at 8:57 PM, Pavel Stehule <pavel.stehule@gmail.com>wrote:
> 2011/6/22 Peter Eisentraut <peter_e@gmx.net>:
> > On ons, 2011-06-22 at 02:39 -0700, Samuel Gendler wrote:
> >> Pavel suggested using a collation of ucs_basic, but I get an error
> >> when I
> >> try that on linux:
> >>
> >> $ createdb -U u1 --lc-collate=ucs_basic -E UTF-8 test
> >> createdb: database creation failed: ERROR: invalid locale name
> ucs_basic
> >
> > ucs_basic is a collation name, which is an SQL object. The argument of
> > createdb --lc-collate is an operating system locale name. You can't mix
> > the two, even though they are similar.
> >
>
> ok, what I can to select, when I would to use a C like default order?
>
>
You can specify 'order by f1 using ~<~' or 'order by f1 using ~>~' in your
query. If you want your queries to use an index when ordering or comparing
strings via LIKE, then you need to create a separate index that uses
varchar_pattern_ops instead of the default varchar_ops. The db will
automatically use the varchar_pattern_ops index when appropriate.
varchar_pattern_ops uses C-like collation.
create index t1_f1_pattern on t1 (f1 varchar_pattern_ops)
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To: pgsql-sql@postgresql.org
Cc: sgendler@ideasculptor.com, pavel.stehule@gmail.com, peter_e@gmx.net, eyal@impactsoft.co.il
Subject: Re: a strange order by behavior
In-Reply-To: <BANLkTikCX59HXnvom_LQDT7eYf3OeCQMDg@mail.gmail.com>
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