DaRLing: A Datalog rewriter for OWL 2 RL ontological reasoning under SPARQL queries

摘要

The W3C Web Ontology Language (OWL) is a powerful knowledge representation formalism at the basis of many semantic-centric applications. Since its unrestricted usage makes reasoning undecidable already in case of very simple tasks, expressive yet decidable fragments have been identified. Among them, we focus on OWL 2 RL, which offers a rich variety of semantic constructors, apart from supporting all RDFS datatypes. Although popular Web resources - such as DBpedia - fall in OWL 2 RL, only a few systems have been designed and implemented for this fragment. None of them, however, fully satisfy all the following desiderata:(i)being freely available and regularly maintained;(ii)supporting query answering and SPARQL queries;(iii)properly applying thesameAsproperty without adopting the unique name assumption;(iv)dealing with concrete datatypes. To fill the gap, we presentDaRLing, a freely available Datalog rewriter for OWL 2 RL ontological reasoning under SPARQL queries. In particular, we describe its architecture, the rewriting strategies it implements, and the result of an experimental evaluation that demonstrates its practical applicability.