Re: Newbie question about db normalization theory: redundant keys OK?

From: David Cressey <>
Date: Fri, 28 Dec 2007 13:45:04 GMT
Message-ID: <A57dj.397$cq5.319_at_trndny06>

"Brian Selzer" <> wrote in message news:lTXcj.3065$

> You're sidestepping the issue. The information need not be preserved in
> database in order to be useful: it may only be needed to decide whether or
> not to permit an update. In any case, your demonstration would not prove
> that there is /always/ a way to tell which transformation actually
> I noticed that you ignored the balance of my last post.

That is plainly and simply not true. If the information is not preserved in the database state, its usefulness vanishes at the same instant that the information vanishes.

Your argument rests, AFAICT, on contradictory views of what constitutes database state. Unless I'm wrong about this, you have crossed over into mysticism as far as I'm concerned. Received on Fri Dec 28 2007 - 14:45:04 CET

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