Re: does a table always need a PK?

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.

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.

-- 
Lee Fesperman, FirstSQL, Inc. (http://www.firstsql.com)
==============================================================
* The Ultimate DBMS is here!
* FirstSQL/J Object/Relational DBMS  (http://www.firstsql.com)