Date: Sun, 22 Jan 2012 19:41:24 +0000
From: David W Noon <dwnoon@ntlworld.com>
To: pgsql-general@postgresql.org
Subject: Re: [GENERAL] hash options
Message-ID: <20120122194124.30c5c19b@karnak.local>
In-Reply-To: <8585BA53443004458E0BAA6134C5A7FB9CD327F6@EGEXCMB01.oww.root.lcl>
References: <8585BA53443004458E0BAA6134C5A7FB9CD327F6@EGEXCMB01.oww.root.lcl>
Organization: Luton Operatic Society
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On Sun, 22 Jan 2012 09:59:55 -0600, Little, Douglas wrote about
[GENERAL] hash options:

>I'm working on a data warehouse dimensionalization process   where I
>need to hash a text string to use as the key. I've implemented with
>MD5.  It works fine,  the problem I have is the size of the md5 (32
>bytes) is often longer than the original string - thus not
>accomplishing what I want - space savings.
>
>Does anybody have alternative hash function recommendations?

Try CRC32, possibly augmented by a CRC16 in a separate attribute.

I have CRC functions for PostgreSQL, written in C, and will make them
available to anybody who wants them.
--=20
Regards,

Dave  [RLU #314465]
*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*
dwnoon@ntlworld.com (David W Noon)
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