Re: A Simple Analysis?

Dan Wu wrote:

> > Case 3
> > ------
> > A B C
> > 0 0 0
> > 0 1 1
> > 1 0 2
> > 1 1 2
> >
> > ??? Here it appears that A partitions all the possible values for C.
> > What kind of dependency is here and how (if at all) should it
> > be decomposed?
> Hi,
> It seems we have a MVD in your Case 3, it is
> A->->B|C. Once you admit it is a MVD, it is easy to
> decompose your case 3 as follows,
> r(ABC)=r(AB) njoin r(AC).
>
> Dan

Hi Dan,

Since for the same value of A (0 for example) you have many values in B (0, 1) and in C (0, 1) there aren't any kind of dependency from A. In that case A is dependent only on C.

Raimundo Lozano Received on Tue May 30 2000 - 00:00:00 CEST