SPARQL query answering over OWL ontologies

Kollia, I; Glimm, B; Horrocks, I

dc.contributor.author	Kollia, I	en
dc.contributor.author	Glimm, B	en
dc.contributor.author	Horrocks, I	en
dc.date.accessioned	2014-03-01T02:47:28Z
dc.date.available	2014-03-01T02:47:28Z
dc.date.issued	2011	en
dc.identifier.issn	03029743	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/33166
dc.subject	Complexity Class	en
dc.subject	Conjunctive Queries	en
dc.subject	Query Answering	en
dc.subject	Query Language	en
dc.subject	Query Rewriting	en
dc.subject	System Performance	en
dc.subject.other	Complex class	en
dc.subject.other	Complex queries	en
dc.subject.other	Conjunctive queries	en
dc.subject.other	Deployed systems	en
dc.subject.other	Expressive semantics	en
dc.subject.other	OWL ontologies	en
dc.subject.other	Prototypical implementation	en
dc.subject.other	Query answering	en
dc.subject.other	Query execution	en
dc.subject.other	Query execution time	en
dc.subject.other	Query rewriting techniques	en
dc.subject.other	Reasoning tasks	en
dc.subject.other	Three orders of magnitude	en
dc.subject.other	Ontology	en
dc.subject.other	Optimization	en
dc.subject.other	Query languages	en
dc.subject.other	Semantics	en
dc.subject.other	User interfaces	en
dc.subject.other	World Wide Web	en
dc.subject.other	Semantic Web	en
dc.title	SPARQL query answering over OWL ontologies	en
heal.type	conferenceItem	en
heal.identifier.primary	10.1007/978-3-642-21034-1_26	en
heal.identifier.secondary	http://dx.doi.org/10.1007/978-3-642-21034-1_26	en
heal.publicationDate	2011	en
heal.abstract	The SPARQL query language is currently being extended by W3C with so-called entailment regimes, which define how queries are evaluated under more expressive semantics than SPARQL's standard simple entailment. We describe a sound and complete algorithm for the OWL Direct Semantics entailment regime. The queries of the regime are very expressive since variables can occur within complex class expressions and can also bind to class or property names. We propose several novel optimizations such as strategies for determining a good query execution order, query rewriting techniques, and show how specialized OWL reasoning tasks and the class and property hierarchy can be used to reduce the query execution time. We provide a prototypical implementation and evaluate the efficiency of the proposed optimizations. For standard conjunctive queries our system performs comparably to already deployed systems. For complex queries an improvement of up to three orders of magnitude can be observed. © 2011 Springer-Verlag Berlin Heidelberg.	en
heal.journalName	Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)	en
dc.identifier.doi	10.1007/978-3-642-21034-1_26	en
dc.identifier.volume	6643 LNCS	en
dc.identifier.issue	PART 1	en
dc.identifier.spage	382	en
dc.identifier.epage	396	en