Re: Dawn doesn't like 1NF

"Laconic2" <laconic2_at_comcast.net> wrote in message news:<sNGdne8i4MF0X_LcRVn-sQ_at_comcast.com>...
> "Dan" <guntermann_at_verizon.net> wrote in message
> news:3e68f717.0410141738.5a248ae2_at_posting.google.com...
>
> > Open any basic discrete mathematics textbook of your choosing. Next,
> > turn to the chapter on relations. I challenge you to produce an
> > example problem and solution where relational operators operate over
> > domains of set values, lists, or "non-simple types" with internals
> > exposed. I think you will find that almost all cases specify
> > relations over domains of elements - nothing more, nothing less.
> > Interestingly, this corresponds well with predicate and propositional
> > logic.
>
> ISTM that a textbook is going to begin with simple examples. If you are
> explaining relaional operators, for the first time,
> it seems to me that all the operands are goping to be sets of simple things.
> The absence of relations on domains of relations in introductory material
> doesn't prove that it isn't useful or powerful.

I don't doubt that introductory textbooks begin with simple examples. Even more than useful or powerful properties, however, one needs a mathematical/logical model that is consistent and complete. I'm simply asking for someone to show me this more powerful and useful model in mathematics that is also as consistent and complete as the "basic" definition of a relation. Sho' me the money.

It shouldn't be that hard to produce an example or "proof" to demonstrate one's assertion, right?

>
> I concur. IMO, I've gotten more power, with less complexity out of the RDM,
> even through the stimgmatic lens of SQL, than out of any other single topic
> in IT. I think, but I'm not sure, that Date has the answer to the
> question you raise.
> Why haven't I read it yet? Becasue I haven't needed to.

I've read Date's ideas on this, and I respect them immensely, but I am not entirely convinced that all the fundamental issues have been addressed, such as how calculii and algebra are affected by his model.

I noticed that Date and Co. have been researching lot's of books on logic these days.

Regards,

Dan Received on Fri Oct 15 2004 - 22:09:59 CEST