Re: Noninferential vs. inferential DBMS

From: Paul <paul_at_test.com>
Date: Fri, 14 May 2004 11:23:09 +0100
Message-ID: <o61pc.3223$wI4.331711@wards.force9.net>

x wrote:

>>A non-inferential database is one that you can add data to but you can't
>>get ANYTHING  out? i.e. you can infer nothing from it? So you can INSERT,
>>UPDATE or DELETE but not SELECT?

>
> No. ANYTHING is too much. Of course you can get SOMETHING out.
>
> in-fer-ence (in'fuhr uhns, -fruhns) n.
> 3. Logic.
> a. the process of deriving from assumed
> premises either the strict logical
> conclusion or one that is to some
> degree probable.
> b. a proposition reached by a process
> of inference.

OK so you're saying you can retrieve the propositions you put in, but you can't do any queries that would involve any of the relational operators like projection, joins etc?

In other words, it's based on propositional logic but not predicate logic? So you can't use "for all" or "there exists"?

For example, suppose you have an employee table, you could get out of it that "Fred Smith has empid=123, works in dept 10 and has a salary of 10,000". But you wouldn't be able to ask "Is there an employee called Fred Smith?

Paul. Received on Fri May 14 2004 - 05:23:09 CDT