Re: md5() sorting

From: Lew <lew(at)lwsc(dot)ehost-services(dot)com>
To: pgsql-general(at)postgresql(dot)org
Subject: Re: md5() sorting
Date: 2007-11-12 19:53:55
Message-ID: 4oSdncY2-KHOMqXanZ2dnUVZ_ufinZ2d@comcast.com
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-general

Karsten Hilbert wrote:
> On Wed, Nov 07, 2007 at 05:36:47PM +0200, Marko Kreen wrote:
>
>>>> I'm wondering if you cast the md5sum as a bytea instead of text and
>>>> then sort, if that would solve it simply.
>>> Along the lines of
>>>
>>> ... ORDER BY decode(md5('...'), 'hex');
>>>
>> Maybe using digest(.., 'md5') function from pgcrypto would be better?
>> It gives bytea immidiately.
>
> Sounds better at first, yes, but requires pgcrypto to be
> installed on machines onto which GNUmed is to be deployed.
>
> Thanks for the suggestion, though.

Since an MD5 hash is a byte array, using text (or any locale-encoded
representation) of it is a mistake. Hashes are not strings and shouldn't be
treated as such.

--
Lew

In response to

Responses

Browse pgsql-general by date

  From Date Subject
Next Message Lew 2007-11-12 19:54:37 Re: float to int
Previous Message Scott Marlowe 2007-11-12 19:52:43 Re: WAL segments size