Re: General Logic Programming Question

[Salvador Abreu]

> I suppose that one could connect a Prolog runtime to a
> database backend in the canonical n-tiered approach, but it
> seems that much of Prolog's built-in searching behaviors would
> be lost because all queries would have to be reformulated in
> standard SQL syntax.  Or do the existing database bindings
> somehow work around this problem?

Integrating Prolog with database engines has been around for
some time now, as a concept.  A recent example involving GNU
Prolog (excuse the plug ;-) is the ISCO system which provides a
regular Prolog interface augmented with database predicates
(datalog) which are stored externally, in a RDB.  You get
persistence.

ISCO dynamically generates SQL queries, which are then fed to a
database interface, which presently includes a native PostgreSQL
and an UnixODBC version.  Check out
http://home.di.uevora.pt/~spa/papers/isco/ for more information.

It's presently in pre-beta state, but I can provide a working
version, in the form of a Debian package ;-)

../salvador