Date: Fri, 1 Nov 2002 16:10:57 -0500
From: Andrew Sullivan <andrew@libertyrms.info>
To: pgsql-performance@postgresql.org
Subject: Re: Does this matter?
Message-ID: <20021101161057.V5799@mail.libertyrms.com>
Mail-Followup-To: Andrew Sullivan <andrew@libertyrms.info>,
	pgsql-performance@postgresql.org
References: <200211011223.48962.josh@agliodbs.com>
	<20021101125052.Y6303-100000@cypress.adhesivemedia.com>
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	from philip@adhesivemedia.com on Fri, Nov 01, 2002 at 12:53:29PM
	-0800

On Fri, Nov 01, 2002 at 12:53:29PM -0800, Philip Hallstrom wrote:

> > is padded out to the specified length.  Therefore the index on a char(36)
> > column will be a little larger, and thus a little slower, than the char(20).
> >
> 
> Really?  According to this url (search for "Tip") there is no performance
> difference just a space difference.  I don't know for sure either way, but
> if there is a difference the manual needs updating.

Hmm.  Maybe a clarification, but I don't think this is quite what the
tip is talking about.  The tip points out that part of the cost is
"the increased storage" from the blank-padded type (char) as
contrasted with non-padded types (like text).  The tip isn't talking
about whether a length of 20 is faster than a length of 36.  Anyway,
I can't really believe the length would be a big deal except on
really huge tables.

A

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