Re: Interpretation of Relations

vc wrote:
>
> On Jan 23, 4:31 pm, Joe Thurbon <use..._at_thurbon.com> wrote:
>

>>> What's your definition of a "valid implication" ?Sorry, I should have said 'valid inferences'. Or perhaps 'what is the
>> proof theory of the relational calculus'.
>>

You can only do this when

(a) you have a translation from relations to logical sentences, or (b) you know what the 'inference rules' are for the 'relational sentences'

I'm not suggesting that such things don't exist, just the I don't understand them properly.

> Also, you may want to read about
> Prolog/Datalog approach to deductive databases.

I've used Prolog quite a bit, and understand it quite well. But am not familiar with datalog. Thanks for the pointer.

> For example, see
> "Foundations of Databases" by Serge Abiteboul and others for
> connections between FOL, database constraints, Datalog, and lots of
> other stuff. It's a more theoretical and solid book than the usual
> crop like "Learn SQL in 60 minutes".
>

I'll add it to the list. Thanks.

Cheers,
Joe Received on Wed Jan 24 2007 - 00:43:13 CET