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

TL;DR

DaRLing is a freely available Datalog rewriter designed for OWL 2 RL ontological reasoning with SPARQL queries, addressing gaps in existing systems by supporting query answering, proper handling of sameAs, and concrete datatypes.

Contribution

It introduces DaRLing, a novel, open-source Datalog-based system that fully supports OWL 2 RL reasoning with SPARQL, filling a significant gap in existing tools.

Findings

Demonstrates practical applicability through experimental evaluation

Supports query answering and SPARQL queries effectively

Properly handles sameAs and concrete datatypes in OWL 2 RL

Abstract

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 the sameAs property without adopting the unique name assumption; (iv) dealing with concrete datatypes. To fill the gap, we present DaRLing, 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. This paper is under consideration in Theory and Practice of Logic Programming (TPLP).