More efficient datalog queries

Abstract

Given a set of Datalog rules, facts, and a query, answers to the query can be inferred bottom-up starting with the facts or top-down starting with the query. The dominant strategies to improve the performance of answering queries are reusing answers to subqueries for top-down methods, and transforming rules based on demand from the query, such as the well-known magic sets transformation, for bottom-up methods. However, the performance of these strategies vary drastically, and the most effective method has remained unknown.