Date: Tue, 28 Aug 2007 11:19:08 -0400
From: Andrew Sullivan <ajs@crankycanuck.ca>
To: pgsql-sql@postgresql.org
Subject: Re: Database normalization
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On Tue, Aug 28, 2007 at 04:15:01PM +0100, Sebastian Ritter wrote:
> > I'd put it in its own table, probably, unless you're going to use it
> > frequently.
> 
>   Why would frequency of use change whether or not I use one or two tables?

If you have a possibly-large field that does not get used very much,
you have to pay the I/O for it every time you look at that row, even
if it's not used.  Also, it sounds like it might not be used by every
row?  In that case, normalization calls for it to be pushed out too.

A

-- 
Andrew Sullivan  | ajs@crankycanuck.ca
However important originality may be in some fields, restraint and 
adherence to procedure emerge as the more significant virtues in a 
great many others.   --Alain de Botton