Re: Noninferential vs. inferential DBMS

From: Paul <paul_at_test.com>
Date: Mon, 17 May 2004 16:44:37 +0100
Message-ID: <R55qc.4379$wI4.499382@wards.force9.net>

x wrote:
> Or is projecting the tuple
> ('Fred Smith', 123, 10, 10,000)
> onto
> ('Fred Smith', 123, 10)
> an 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.

But by itself the tuple ('Fred Smith', 123, 10, 10000) is meaningless.

The DBMS just does does the mechanics, it can't know that the first column is a name, etc. In other words it can't know the real-world interpretation of the underlying predicate. So I'm still not sure what is meant by the DBMS inferring things.

Paul. Received on Mon May 17 2004 - 10:44:37 CDT