Re: Relational Lattice, what is it good for?

Marshall Spight wrote:
> vc wrote:
> > Marshall Spight wrote:
> > [...]
> >
> > That does not make any obvious sense. What is '(a, b, ab)' ? Is it
> > the union of sets of attributes [of their respective relations] or
> > something else ? You did not define the expression.
[...]
> So '(a, b, ab)' contains all the attributes that are only in A,
> all the attributes that are only in B, and all the attributes
> that in in both A and B.

Assuming 'contains' means 'is the union of', '(a, b, ab)' is obviously 'a union b' and 'ab' is clearly redundant. Is that what you mean ?

>
>
> HTH
>
>
> Marshall
Received on Fri Feb 17 2006 - 19:16:05 CST