Re: equivalence of functional dependencies

shannon <shannon_at_nolunchmeat.com> schrieb:
> I have tried an example from the elmasri book, perhaps somebody can pass
> judgement on my logic,
>
> two sets of functional dependencies F= {A > C, AC > D, E > AD, E > H}
> and G = {A > CD, E > AH}. Check whether or not they are equivalent.
>
> here I make conclusion that they are not equivalent,

I don't know about the official way to do this, but by inspection C > D is derivable from F but not G, so they can't be equivalent. Received on Fri Jan 09 2004 - 02:46:17 CET