SpeCS — SPARQL Query Containment Solver

With increasing popularity and importance of Semantic Web and its application, SPARQL, as a standard language for querying RDF data, gains more importance and receives additional attention from both practitioners and researchers coming from various domains. In database world, the query containment problem is a fundamental problem, crucially important in verification and optimization of queries. In this paper, we present our work on developing SPECS, an efficient solver for this problem in SPARQL query language. Our approach reduces query containment problem to the satisfiability problem in theories of the first order logic, and exploits SMT solver Z3 for checking the constructed formula. We present an evaluation that shows that our solver is much faster and covers more language features than the other available state-of-the-art solvers.