Re: Noninferential vs. inferential DBMS

• Post for FREE via your newsreader at post.usenet.com ****

"mAsterdam" <mAsterdam_at_vrijdag.org> wrote in message news:40a5336e$0$15440$e4fe514c_at_news.xs4all.nl...
> x wrote:
> > ... I mean automated logical inferences performed by the DBMS.
>
> Could you please give an example (or testcase if you prefer)?

Paul's example:

Or is projecting the tuple
('Fred Smith', 123, 10, 10,000)
onto
('Fred Smith', 123, 10)
and example of inference?

The answer is:
This depends if the projection was done by the DBMS or by the application programmer/database user.
If the DBMS had a rule that said (a, b, c , d, e) -->(a, b, c) and this rule was used, then projecting the tuple is an example of inference.

-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

• Usenet.com - The #1 Usenet Newsgroup Service on The Planet! *** http://www.usenet.com Unlimited Download - 19 Seperate Servers - 90,000 groups - Uncensored -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=