Re: Constraints and Functional Dependencies

On 25 fév, 03:01, paul c <toledobythe..._at_oohay.ac> wrote:
> Marshall wrote:
> > On Feb 24, 11:28 am, paul c <toledobythe..._at_oohay.ac> wrote:
>
> >>It looked to me as if the OP did define it. I've seen the same
> >>definition expressed in equivalent algebra here many moons ago.
>
> > Specifically I defined a particular kind of FD which is equivalent
> > to a candidate key. An FD in turn being a particular kind
> > of constraint.
>
> > Hmmm. Can we express keyness otherwise? I can't think how.
>
> SOL (I'm suspect), but that's another topic, as far as most people are
> concerned. I don't say it's better, just that I haven't seen anybody
> yet say why it's worse.
Hi paul,

I disagree. I doubt one can characterize fd, an ellaborate conceptual scheme, without clarifying first keyness issue on which fd relies. Have not seen any convincing proposal so far. Received on Sun Feb 25 2007 - 11:53:07 CET