Re: Proposal: 6NF

From: dawn <dawnwolthuis_at_gmail.com>
Date: 9 Oct 2006 17:15:08 -0700
Message-ID: <1160439308.677121.226700_at_i3g2000cwc.googlegroups.com>


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. There are many languages that employ 2VL. SQL is the odd-ball out. From what I can tell, many relational theorists think 3VL is a mistake as well. The s/w dev industry would be well-served to get away from 3VL as soon as feasible.  Those without any installed based might be well-served to start fresh without using 3VL with their DBMS today. --dawn Received on Tue Oct 10 2006 - 02:15:08 CEST

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