Re: How to normalize this?

On Friday, May 10, 2013 2:03:27 AM UTC-7, com..._at_hotmail.com wrote:
> On Friday, May 10, 2013 1:29:36 AM UTC-7, Jan Hidders wrote:
> > R{A, B} S{B, C} with { R.B -> R.A, S.B -> S.C, R[B] => S[B], S[B] => R[B] }
> > which perhaps should be normalized to:
> > T'{A, B, C} with { T.B -> T.A, T.B -> S.C }
>
> But now the keys imply the JD (and the INDs) so you don't need to declare/mention it (or them).

I was trying to express that any such T'(A,B,C) with FDs from its key and no explicit JD or INDs can decomposed to such projections so given the FDs and the JD or INDs we can obviously go the other way.

philip Received on Fri May 10 2013 - 11:28:49 CEST