From: David Cressey <>
Date: Sun, 06 Jan 2008 12:04:47 GMT
Message-ID: <zt3gj.1467$tZ6.1284_at_trndny03>

"Carlos M. Calvelo" <> wrote in message On 5 jan, 16:29, "David Cressey" <> wrote:
> "Roy Hann" <specia..._at_processed.almost.meat> wrote in message
> > "David Cressey" <> wrote in message
> >news:VwKfj.321$vX6.267_at_trndny05...
> > > I disagree. A null doesn't indicate that information exists. There is
> > > always the "not applicable" case
> > Which, I believe, is almost invariably the reason that nullable
> > get introduced in real databases. I continue to be baffled at this
> > preoccupation with flagging information that must exist but isn't known.
> > Discuss it if you must (I absolutely don't care about it), but don't
> ignore
> > the more common problem.
> The "not applicable" case is the one that can be obviated by

That is indeed the obvious case.

> Even with full
> normalization there can be facts that the database doesn't know, and knows
> that it doesn't know. There can also be facts that the database doesn't
> know, and doesn't know that it doesn't know.

Here is a better explanation:

Sorry, could not resist.

I intended the veiled reference to Rumsfeld. Nice Catch.

Carlos Received on Sun Jan 06 2008 - 13:04:47 CET

Original text of this message