Re: does a table always need a PK?

"Lee Fesperman" <firstsql_at_ix.netcom.com> wrote in message news:3F4C72A9.6003_at_ix.netcom.com...
> Bob Badour wrote:
> >
> > "Heikki Tuuri" <Heikki.Tuuri_at_innodb.com> wrote in message
> > news:big0dj$3m9$1_at_phys-news1.kolumbus.fi..
> > >
> > > for example, there are no NULLs in a mathematical relation.
> >
> > That's arguable and depends entirely on what you think a NULL is. A set
can
> > contain anything.
> >
> > > Since Lee believes Codd's 12 rules describe a 'relational' database,
> >
> > Does he? I suspect Lee might have a more nuanced belief system than you
> > attribute to him. Perhaps, you and I could agree to let him speak for
> > himself.
>
> As I said in a previous posting. Codd's 12 rules are guidelines for a user
to determine
> the relational compliance of a DBMS.
>
> > > > When other SQL vendors stop making specious claims about being
> > > > relational, I am sure Lee will stop too.
> > >
> > > Is this not intellectual dishonesty?
> >
> > No, not necessarily. Perhaps, Lee will indulge us and allow us to judge
his
> > competence, intellectual honesty and integrity by answering the
following
> > questions. Heikki, you can indulge us by doing the same.
> >
> > Lee, are you game? Heikki?
> >
> > ...
>
> Yes, I am game. I hope you will indulge a few days before I answer. I will
be out of
> town tomorrow.

By all means, Lee, take all the time you need. I have no right to demand any of your time, and I appreciate any time you volunteer to indulge me. I would not want you to cite time pressures for avoiding any of the questions. I tried to make my questions firm, revealing but fair. I hope I succeeded.

> Before I go, I would like to correct a misapprehension ...
>
> FirstSQL/J is the only DBMS supporting 2 types of nulls, following Codd.
But, it
> supports 3VL (far more soundly than other vendors) rather than 4VL.
FirstSQL/J follows
> what I colloquially call the 'Tasmania' Relational Model of Data ---
basically Codd's
> 1979 definition of the Relational Model. In 1979, Codd recommended 2 types
of nulls
> within a 3VL framework.

I believe Codd referred to that paper as RM/T. I have never found a copy of that particular paper. Do you know of an online resource that has it? Received on Wed Aug 27 2003 - 16:49:56 CEST