Re: Does Codd's view of a relational database differ from that of Date & Darwin? [M.Gittens]

From: David Cressey <>
Date: Sat, 11 Jun 2005 08:44:55 GMT
Message-ID: <bwxqe.2732$>

"Jan Hidders" <> wrote in message news:Bkkqe.115913$
> I'm not sure what it means to be an "inherent part of the theory" but
> Codd describes non-simple domains as "undesirable" and in section 1.5 he
> argues in favour of flat relations. This becomes even more clear if you
> look at the articles that followed because, for example, the notion of
> "relational completeness" (and the relationship with first-order logic)
> doesn't make much sense if you allow nested relations.

I may be reading more out of the 1970 paper than Codd intended to say, but the word "undesirable" suggests something far different to me than the word "impossible".

What I'd be curious to know is whether it's an undesirable burden to place on the DBMS implementor, an undesirable alternative to place in the hands of the database designer, an undesirable avenue for further exploration of the theory, or something else. Received on Sat Jun 11 2005 - 10:44:55 CEST

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