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Re: Do Data Models Need to built on a Mathematical Concept?

From: Paul Vernon <paul.vernon_at_ukk.ibmm.comm>
Date: Wed, 7 May 2003 17:15:16 +0100
Message-ID: <b9be8k$1vs0$2@gazette.almaden.ibm.com>


"Neo" <neo55592_at_hotmail.com> wrote in message news:4b45d3ad.0305061301.5a821adb_at_posting.google.com... [snip]
> I would say it is even better to see a relation as a a set of things.
> The fact that the thing belongs to the set is all the fact that is
> required.
> The fact that the thing belongs to the set is all the truth that is
> required.

Neo, you did well in explaining your understanding. I understand your understanding. However your understanding is an incorrect understanding of the meaning of relations. A tuple in a relation is a statement about things in the world, it is not (in general) a 'thing' itself. The things are the values in a domain. I
very strongly suggest you read at least slides 17 to 20 from C. J. Date's VLDB'02 keynote:

http://www.cs.ust.hk/vldb2002/program-info/keynotes.html#Keynote%202 http://www.cs.ust.hk/vldb2002/VLDB2002-proceedings/slides/S01P02slides.pdf

Regards
Paul Vernon
Business Intelligence, IBM Global Services Received on Wed May 07 2003 - 11:15:16 CDT

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