Re: Lucid statement of the MV vs RM position?
Date: 24 Apr 2006 06:28:21 -0700
Jon Heggland wrote:
> dawn wrote:
> > David Cressey wrote:
> >> I agree with you about the large number of crap designs, which I call
> >> "stupid database tricks". But I think the solution is to teach better
> >> design skills, and develop better platforms, rather than to dismiss the
> >> RM.
> > We can do both ;-) We ought not dismiss relations, nor modeling with
> > relations, but we do need to go beyond the RM to include lists, for
> > example, which the Information Principle (of the RM) does not permit.
> I think (hope?) you mean "we do want to go beyond SQL to include lists,
> for example, which SQL does not permit".
Well, no, I was sticking to the Information Principle for RM. Are you suggesting that attributes whos values are lists are now acceptable within the RM?
If so, then some of the big issues I originally had with the RM, including 1NF (normalization per Codd), 3VL (Codd's 3rd Rule), and lack of support for lists would all now be accepted as if they were the RM. If the IP is gone, then I'm in (there are still typing and constraints issues, but the RM takes a reasonable approach to those even if I can also see the value in other strategies).
Maybe the RM has been redefined so as to dump much of what has been taught as the RM and much of what has been implemented as the RM. Then what's left is to get the word out. I think the easiest way to do that would be to say that the RM is no longer the model -- let's give it a new name. It is much harder to get the word out that something has changed so drastically as to no longer be what it was and what people think it is if the terms and rules keep getting redefined. Changing 1NF to mean something altogether different (or nothing at all) does not help make it clear that the industry is moving on, for example.
So, let me know if the IP is no longer applicable and where there are any implementations of this new approach. Thanks. --dawn Received on Mon Apr 24 2006 - 15:28:21 CEST