Re: md5() sorting

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