prolog to SQL converter

Question

Without thinking to much, it seems to me that a large set of Prolog's functionality could be implemented as relational calculus (a.k.a. SQL).

Has anyone heard of any tools to automatically convert Prolog to SQL?

Answer 1

Yes, of course.

A premise for skeptics: any semi-decent book on database theory mentions Datalog (which is Prolog-like) and theorems which demonstrate that is possible to translate it to/from Relational Algebra (RA) (under specific restrictions).

SQL is not faithful to RA or relational calculi, but is enough to support Prolog:

• Christoph Draxler has developed a Prolog to SQL compiler (PL2SQL) for his thesis, available for download (.tgz) - also here at CMU Artificial Intelligence Repository (it was adapted and included in at least: Ciao Prolog and SWI-Prolog via Blipkit - Biomedical LogIc Programming Knowledge Integration Kit);
• Igor Wojnicki has developed for his PhD (A Rule-based Inference Engine Extending Knowledge Processing Capabilities of Relational Database Management Systems) a prototype system implementing his Jelly View technology called ReDaReS, but it seems not available for download;
• Relational Abstract Machine (RAM) translates Prolog to Relational Algebra, but it doesn't seems to have a SQL backend;
• Walter D. Potter has a couple of papers on Prolog/RDBMS integration;
• Kevin Boone's paper on Using SQL with Prolog to improve performance with large databases is also interesting;
• and so on...