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

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
>
> http://tinyurl.com/68rbm
>
> (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. Are you a Mathematica user per chance ?

vc Received on Thu Jul 07 2005 - 19:51:40 CEST