From: andrew@pillette.com
To: valgog <valgog@gmail.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: multicolumn index column order
Date: Tue, 24 Jul 2007 00:10:30 -0700
Message-ID: <200707240710.l6O7AUu24090@pillette.com> (raw)
valgog <valgog@gmail.com> wrote ..
> On Jul 23, 7:00 pm, t...@sss.pgh.pa.us (Tom Lane) wrote:
> > valgog <val...@gmail.com> writes:
> > > how to build an multicolumn index with one column order ASCENDING and
> > > another column order DESCENDING?
> >
> > Use 8.3 ;-)
> >
> > In existing releases you could fake it with a custom reverse-sorting
> > operator class, but it's a pain in the neck to create one.
I've often gotten what I want by using a calculated index on (f1, -f2). ORDER BY will take an expression, e.g. ORDER BY f1, -f2. Simpler than a custom operator.
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To: pgsql-performance@postgresql.org
Cc: andrew@pillette.com, valgog@gmail.com
Subject: Re: multicolumn index column order
In-Reply-To: <200707240710.l6O7AUu24090@pillette.com>
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