Re: Little question for RDM theoristes

"U-gene" <grigoriev-e_at_yandex.ru> wrote in message news:1150439134.710656.250070_at_g10g2000cwb.googlegroups.com...
> Two relations (relvalues) exists. These relations have different
> headers (schemas). Are these relvalues the values of different types?

> IMHO all relvalues have the same type and the headers is just data. May
> be it is special kind of data which is different from rel.bodies' data.
> . But persons exist who think in other way - if relvalues have
> different headers they are values of different types. So I'll glag to
> hear your opinions.

My opinion is that Codd's "relations" were all (relvar name, relationship) pairs.
The header is the intension, the body is the extension.

I'm not sure about Date model because I have not studied the TTM carefully enough.
He made a lot of fine distinctions between variables and values, variables and variable, values and pointers, etc. Too fine for my taste. I think it is called splitting the hair in four or the theory of matches. Received on Fri Jun 16 2006 - 10:09:51 CEST