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

From: David Cressey <>
Date: Sun, 12 Jun 2005 03:16:34 GMT
Message-ID: <mONqe.2617$>

"Jan Hidders" <> wrote in message news:jDyqe.116442$

> The relational model is more a *prescriptive* theory than a
> *descriptive* theory. In such a context these words are not that far
> apart. Moreover, as a mathematical statement it would simply be wrong to
> say that nested relations are impossible.

This makes a lot of sense to me. But then, I consider most of "computer science" to be more aptly called "computer engineering".

> I think one needs to be careful about reading the article too much from
> a modern perspective. The question about what is exactly *the*
> relational model that some here are so obsessed about, wouldn't have
> made much sense to Codd at the time. In fact, it still doesn't.

Yes. I only got involved with that obsession when I got involved in some of the discussions here.

When I learned 1NF, 2NF, 3NF, it was more in the nature of "try it, you'll like it" than some kind of holy grail of computing. I tried it, and I liked it. It was never that much of a deal. Learning when and how to do something other than normalize took a little longer.

> > What I'd be curious to know is whether it's an undesirable burden to
> > on the DBMS implementor, an undesirable alternative to place in the
hands of
> > the database designer, an undesirable avenue for further exploration of
> > theory, or something else.
> They tend to lead away from the goal that is so important in large
> shared databases: data independence.

I'm very curious about this. In what way do simple domains lead towards the goal of data independence and/or relational domains lead away from the same goal? Or am I misconstruing your comment? Received on Sun Jun 12 2005 - 05:16:34 CEST

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