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

From: Mikito Harakiri <>
Date: 7 Jul 2005 11:10:43 -0700
Message-ID: <>

vc wrote:
> Mikito Harakiri wrote:
> > Jon Heggland wrote:
> > > Because it isn't. Temperature is not the union of double, double and
> > > double, or even of fahrenheit, celsius and kelvin. Point is not the
> > > union of cartesian points and polar points. It does not even make sense
> > > to speak of such a union, because the set of cartesian points and the
> > > set of polar points is the same set---the set of 2D points. (0,4) and
> > > (4,90) is the same point, just like 14 and 0xE is the same int.
> >
> > User defined types present rather archaic approach to units. Modern
> > approach is symbolic manipulation
> >
> >
> >
> > (This is well known technique, BTW that has been posted many times on
> > sci.math).
> My impression is that you've got no clue as to what you are talking
> about The impression, of course, can be reversed by trying to present
> your thoughts in a coherent manner.

I have an admirable theory, but the margins of this group are too narrow to accomodate it.

Seriously, if I had better idea, then I would write an article. The best I can suggest is googling "units group:sci.math". First few hits are pretty good ones. Perhaps, in this context that writing would have more sence to you.

> Are you a Mathematica user per
> chance ?

Maple Received on Thu Jul 07 2005 - 20:10:43 CEST

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