Re: A new proof of the superiority of set oriented approaches: numerical/time serie linear interpolation

On 30 avr, 18:08, "Brian Selzer" <b..._at_selzer-software.com> wrote:
> "Cimode" <cim..._at_hotmail.com> wrote in message
>
> news:1177938789.949723.62480_at_h2g2000hsg.googlegroups.com...
> [snip]
>
> > I am aware of that article but thank you for reminding it. It simply
> > a negation of previous work and has been demonstrated since as wrong
> > by Codd's disciples (Date, Darwen). The induction of NULL 3VL simply
> > breaks the POCW (Principle of Closed World) redefining the meaning of
> > a database as a collection of facts. I think of this tolerance as one
> > of Codd's errors.
>
> In a closed world, there is no such thing as "missing information." Can you
> provide a reference that states that Codd adopted the closed world
> assumption? I've never read that he did, and in light of his views on
> missing information, I would be surprised if he had. In an open world, the
> focus is on what has been stated, and the contents of a database is a
> collection of recorded facts, not a collection of all of the facts. D&D's
> interpretation of the RM differs from Codd's in several substantive ways.
> Aside from missing information, Codd never described a database as a
> collection of relvars. In everything I've read, he has always referred to
> database modifications as inserts, updates and deletes. This would follow,
> since inserts, updates and deletes are statements that specify how what is
> known about the universe now differs from what has already been recorded.
> D&D's interpretation posits that insert, update and delete are simply
> instances of relational assignment, blissfully ignoring their inherent
> dependency on the current state.

database = collection of facts Received on Mon Apr 30 2007 - 18:49:34 CEST