A Method Based on Query Caching and Predicate Substitution for the Treatment of Failing Database Queries

摘要

This paper proposes an approach aimed at obviating empty answers for a family of conjunctive queries involving value constraints. Contrary to the approaches based on a relaxation of the predicates involved in the query, the principle suggested here consists in replacing the query by a similar one which has been processed previously and whose answer is known to be non-empty. This technique thus avoids the com-binatory explosion induced by classical relaxation-based approaches.