Factorizing Complex Predicates in Queries to Exploit Indexes

Abstract

Decision-support applications generate queries with complex predicates. We show how the factorization of complex query expressions exposes significant opportunities for exploiting available indexes. We also present a novel idea of relaxing predicates in a complex condition to create possibilities for factoring. Our algorithms are designed for easy integration with existing query optimizers and support multiple optimization levels, providing different trade-offs between plan complexity and optimization time.