Re: So what's null then if it's not nothing?

"JOG" <jog_at_cs.nott.ac.uk> wrote in message news:1132574034.654280.270710_at_o13g2000cwo.googlegroups.com...
> > Consider the question "When did you stop beating your wife?"
> >
> > Someone who is unmarried can't respond with a date, even though they
> > know the answer. The correct answer is Null, but this does not mean that
> > the answer is unknown. Any debate that works on the assumption that Null
> > necessarily means unknown is based on a false premise and will possibly
> > produce paradoxical conclusions.
>
> Well this is exactly the point. It is not the question that we should
> care about. In fact the question should be almost irrelevant - it's the
> answers that the database should be concentrating on encoding (and none
> will be "Null"). Extrapolating out answers for a tweaked question:
>
> "When did meet your wife?" - 2001
> "When did meet your wife?" - I am not married
> "When did meet your wife?" - I can't remember.
>
> yields 3 facts as a result. And these all fulfill different predicates.
> Go figure. Yet these forms of responses are so prevalent in human
> discourse, surely the indication is that the DBMS systems we are
> currently presented with (by which I refer to the management systems
> themselves and not the RM underpinnings) are insufficient.

"When did meet your wife?" - What's a wife ? :-) Received on Thu Nov 24 2005 - 09:10:56 CET