Re: Functional and mulitvauled depencies?

Hi Dan,

On behalf of my classmates. I would like to ask why does BC->A hold. Any help would be appreciated.

Regards,
Chee Sin

Dan Wu wrote:

> > Hi
> > If i have the following set of relation, say S with the following tuples
> > A B C
> > t1 A1 b2 c3
> > t2 a4 b2 c3
> > t3 a5 b3 c3
> > t4 a5 b3 c4
> >
> > Then, which of the following functional and multivalued depencies does not
> > hold over relation S?
>
> a) B -> C does not hold by definition.
>
> all the other three hold by definition.
>
> > b) B ->-> C
> > c) A ->-> B
> > d) BC -> A
> >
> >
> >
> >
> > --
> > Regards
> > Low Y S
> > ICQ:3140912
> > Pse return mail to: slasher_at_edsamail.com.sg
> > (P.S Not more than 500K attachments)
> >
> >
> >
Received on Wed Apr 19 2000 - 00:00:00 CEST