Melisachew Wudage Chekol, Jérôme Euzenat, Pierre Genevès, Nabil Layaïda, PSPARQL query containment, Research report 7641, INRIA, Grenoble (FR), 32p., June 2011
Querying the semantic web is mainly done through SPARQL. This language has been studied from different perspectives such as optimization and extension. One of its extensions, PSPARQL (Path SPARQL) provides queries with paths of arbitrary length. We study the static analysis of queries written in this language, in particular, containment of queries: determining whether, for any graph, the answers to a query are contained in those of another query. Our approach consists in encoding RDF graphs as transition systems and queries as mu-calculus formulas and then reducing the containment problem to testing satisfiability in the logic. We establish complexity bounds and report experimental results.
Query containment, PSPARQL, Semantic web, RDF, Regular path queries