Re: We aren't a relational database ... ?

On Mon, Oct 08, 2007 at 09:15:29AM -0700, Jeff Davis wrote:
> On Mon, 2007-10-08 at 07:55 -0700, David Fetter wrote:
> > On Sun, Oct 07, 2007 at 07:53:14PM -0700, Jeff Davis wrote:
> > > On Sun, 2007-10-07 at 22:58 -0300, Marc G. Fournier wrote:
> > > > "How many open source relational databases can you name? My
> > > > friend Gabrielle recently sent me the links to two of them.
> > > > However, if you?re like most technical people, you probably
> > > > don?t know any ? just as I didn?t until recently. I can
> > > > already imagine many of you saying ?bulls**t?, what about
> > > > MySQL and PostgreSQL?? (to name just two), but those are just
> > > > databases, not relational databases."
> > >
> > > SQL does have some glaring violations of the relational model,
> >
> > Nope. SQL doesn't conform with *a* relational model espoused by
> > Darwen, Date and Pascal, hereinafter DDP, who are about as
> > connected to database management as Christian Identity is to
> > Christianity. It conforms pretty well to Codd's relational model,
> > and he's the guy who invented the thing.
>
> I haven't heard anyone say before that duplicate tuples were part of
> any relational model.

There is at least one relational model--the one every SQL DBMS is
based on--which uses multisets instead of sets. Multiset theory and
practice turn out to be extremely handy in databases, as they allow
things we take for granted like aggregates and arithmetic on same.

> I'm not saying SQL is bad; it's certainly the best practical data
> language we have.

POSTQUEL was quite a nice language, too. Check out the pre-SQL
sources of POSTGRES.

> The problem I see is that it's the _only_ practical data language in
> existence, and it is (in my opinion) imperfect.

Perfection isn't a human attribute, and there's a lot of evidence to
suggest it isn't a divine one either. How about striving for
excellence instead? That is definitely achievable. :)

Cheers,
D
--
David Fetter <david(at)fetter(dot)org> http://fetter.org/
phone: +1 415 235 3778 AIM: dfetter666
Skype: davidfetter

Remember to vote!
Consider donating to PostgreSQL: http://www.postgresql.org/about/donate