Re: SQL and First Order Logic/ILP
Date: 9 Jul 2002 18:49:40 +0200
Message-ID: <3d2b1424$1_at_news.uia.ac.be>
In article <3d2b0a82.98484863_at_news.compuserve.de>,
Malte Finsterwalder <finsterwalder02_at_web.de> wrote:
>
>What is the relation between the relational model and first oder
>logic?
They are one and the same. The only difference is that in the relational model you get to name your columns whereas in logic you have to talk about the 4'th argument of a predicate. :-) If you look at how models are defined in FOL then you see that consist of a domain of objects/entities and a mapping from predicate names to a set of tuples, one for each instince that makes the predicate true. That's identical to how a database instance looks in the relational model. The whole point of the relational algebra is that it allows you to exactly compute all queries that can be asked with an FOL formula. That is not a coincedence.
>Does anyone happen to have any pointers I could follow to learn more?
How much do you know already? What do you know about logic? What do you know about the relational model? What would you like to learn next?
- Jan Hidders