Evaluating Queries in Deductive Databases by Generating

A strong advantage of bottom up generating techniques is their ability to guarantee finiteness of all inferences in a deductive database system involving recursive axioms. But a "brute force" generating answers to a query would be very inefficient producing many facts useless for the query evaluation. An economy generating method is presented based on discovering explicit facts relevant to the query, and applying preselected axioms as generating rules. The method is proved to be complete in the sense that it generates all the existing answers to the query in a finite time.