Re: L

paul c wrote:
> dawn wrote:
> > paul c wrote:
> >> dawn wrote:
> >>> Hugo Kornelis wrote:
> >>>> On Fri, 06 Oct 2006 23:29:29 GMT, paul c wrote:
> >>>>
> >>>>> Hugo Kornelis wrote:
> >>>> (snip)
> >>>>>> Because relational databases supporting NULL *define* it as a marker
> >>>>>> denoting the absence of a value. Dawn actually makes a good point about
> >>>>>> context: in C for instance, NULL has a completely different meaning.
> >>>>>> ...
> >>>>> Since it has a different meaning in C, there is no point bringing C into
> >>>>> play here.
> >>>> Hi Paul,
> >>>>
> >>>> The point I was trying to make is that NULL has different meaning in
> >>>> different context. Using C as example was a bad choice, since it
> >>>> obfuscated what I was trying to convey, rather than clarifying it.
> >>>>
> >>>> The meaning of NULL in the context of SQL is also quite different from
> >>>> the meaning of NULL in Pick (and possibly other MV databases). That's
> >>>> what I wanted to write, and what I should have written in the first
> >>>> place. Much of the discussion between Cimode and Dawn appears (as I read
> >>>> it) to come from Cimode talking aboout SQL NULL and Dawn talking about
> >>>> Pick NULL - but they both think that the other is discussing the same
> >>>> NULL.
> >>> Thanks for giving your take on that, Hugo, since I was clearly getting
> >>> nowhere.
> >> What else is new.
> >>
> >> You won`t get anywhere as long as you keep comparing apples to oranges,
> >> eg., imagining that Pick has a data model that is comparable to what
> >> Codd had in mind.
> >
> > That is not what this was about, Paul.

>

I would think you could abstract from that statement.

> Too bad I can`t quote Codd here.

His approach to NULL is something that many disagree with today, right?  Think how many hours and dollars the implementation of this approach to NULL has cost the industry. Of course one can define NULL this way, but the costs outweigh the benefits in doing so. --dawn

> But just in an effort to get you on a
> more useful track, did SQL endorse Nulls before or after Codd`s 1979
> paper (question mark intended, sorry the keyboard is fine, something to
> do with whatever Mozilla is doing to firefox or thunderbird).
Received on Tue Oct 10 2006 - 02:47:37 CEST