Semantic Aware Implication and Satisfiability for Conjunctive Queries in Semantic Caching

Abstract

Finding satisfiability and implication results among queries is fundamental to several problems in databases especially in distributed databases. The known complexity of finding satisfiability of term S is O({pipe}S{pipe}3). Similarly complexity of finding "Is S implies T (S→T)" is O(S3+K) Where {pipe}S{pipe} is the number of distinct predicate attributes in S, and K is the number of predicate terms in T (S and T are conjunctive select-project-join(PSJ) queries). We show that with the induction of Cross Attribute Knowledge (CRA) the above complexity is reduced to O({pipe}S - CRA{pipe}3) and O({pipe}S - CRA{pipe}3+K) for satisfiability and implication respectively. © Springer-Verlag Berlin Heidelberg 2012.