Re: Extending my question. Was: The relational model and relational

"Steve Kass" <skass_at_drew.edu> wrote in message news:b328t6$5s6$1_at_slb9.atl.mindspring.net...
> Bob,
>
> First of all, we clearly disagree on what makes a model useful, as well
as
> on boundaries. You separate things into logical, physical and conceptual.
> I think we're pretty close on what the physical is (implementation), but
> it ends
> there. My logical model is the mathematical one, and I don't require it
to
> have suitability for machine processing (I imagine you see my logic that
> way).

Mathematics are suitable for machine processing.

My usage of conceptual, logical and physical comes directly from the ISO/IEC standard vocabularies for computer science and data processing. Since this newsgroup starts with comp.databases, I suggest we stick with the standard definitions for computer science and data processing.

Perhaps, your usage would be conventional and standard in sci.math. I doubt it, but it is possible.

> You and Date insist that cardinality can only be determined by counting,
> which
> requires distinguishability. I have a scale that allows me to determine
> the cardinality
> of a multiset of tuna cans by their collective weight.

If you cannot identify the cans of tuna, how do you place them on the scale? And before you can calculate a count from a weight, you must first count identifiable cans then weigh them.

> Believe it or not, I think there are reasons why some
> tables work well
> with duplicates and others do not. A supplier-parts table should not have
> duplicate rows, for reasons that are clear to me.

Well, if those reasons are clear, you should be able to communicate them clearly instead of just claiming they exist.

> For the record, I'm a proponent of ketchup, too. Please dump some in
> my coffee, since there shouldn't be anything wrong with that. With any
> luck, Ill object, and you can patent the brilliant proof of the
once-elusive
> theorem that ketchup serves no useful purpose.

More handwaving nonsense.

> I think other things work even better for some purposes, that's all, but
you
> or Date or anyone else are welcome to stick to the tried and true, and it
> won't offend me in the least. You can use Roman numerals and shells,
> for all I care.

It's interesting how you are trying to mischaracterize Date as using primitive technology. Multisets are demonstrably more primitive than relations--simply from the fact that they rely on physical location. You are the one promoting the use of "Roman numerals and shells". Received on Fri Feb 21 2003 - 08:13:20 CET