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

From: <michael_at_preece.net>
Date: 22 Nov 2005 19:55:36 -0800
Message-ID: <1132718136.236806.36710@f14g2000cwb.googlegroups.com>

mountain man wrote:

> "paul c" <toledobythesea_at_oohay.ac> wrote in message
> news:OhPgf.573740$1i.24270_at_pd7tw2no...
> > Frank Hamersley wrote:
> >> JOG wrote:
> >>
> >>> michael_at_preece.net wrote:
> >>>
> >>>> "A value of the Boolean data type is either true or false. The truth
> >>>> value of unknown is sometimes represented by the null value."
> >>>>
> >>>> Dodgy or what?! It would be better to use a large cumbersome robot
> >>>> waving its arms about saying "does not compute" than to use null for
> >>>> this.
> >>>>
> >>>> Mike.
> >>>
> >>>
> >>> I for one _really_ hope some database corporate representatives are
> >>> reading this thread, and take this feature into consideration for their
> >>> future releases.
> >>
> >>
> >> Errr...pardon me for being dense...but exactly what is the "feature" we
> >> so desperately need?
> >>
> >> Cheers, Frank.
> >
> > I was trying to exercise restraint, but I guess I've gotten sucked in
> > along with some smart people. puts me in good company, i suppose ...
> >
> > i don't understand why such a question ends up with so much space on the
> > "databases.theory" newsgroup. is it because there is no such group as
> > "comp.databases.practice.etc"?

>
>

> Its because the theory side of databases is lead at the moment
> by a large hand waving robot called "The Pedagogy of the RM".
> This practice (as most human concerns go) is self perpetuating
> and has been at it in excess of 30 years.

>

> The problem is that evolution in the world external to the academic
> vision of the relational model has not been matched by evolution
> of the model, or evolution of its interfaces to other valid models
> and ideas in the (information technology) environment.

>

> Technically, the NULL can mean a different thing to every DBMS
> and its treatment (if any) will vary between vendors. Tabulate the
> vendors of all RDBMS and DBMS software and you will see
> that this is a fact.

Would it be inappropriate to describe this state of affairs as "ridiculous"?

Mike.

>

> Some people believe that unknown and unknowable values
> cannot exist, and they might be happy to contemplate nulless
> existence in a vendor software that represents their notion
> of reality.

>

> Others believe that it is better to allow for the possibility of
> unknown and unknowable values, and select and/or write
> their RDBMS software accordingly.

>
>

> None of this is against the law (yet), so
> opinion is thus diverse.

>
>
>
>
>
>
>
>

> --
> Pete Brown
> IT Managers & Engineers
> Falls Creek, Australia
> www.mountainman.com.au/software
Received on Tue Nov 22 2005 - 21:55:36 CST