Ontop: Answering SPARQL queries over relational databases

Article type: Research Article

Authors: Calvanese, Diego^{a; *} | Cogrel, Benjamin^a | Komla-Ebri, Sarah^a | Kontchakov, Roman^b | Lanti, Davide^a | Rezk, Martin^a | Rodriguez-Muro, Mariano^c | Xiao, Guohui^a

Affiliations: [a] Free University of Bozen-Bolzano, Italy. E-mails: calvanese@inf.unibz.it, bcogrel@inf.unibz.it, sakomlaebri@inf.unibz.it, dlanti@inf.unibz.it, mrezk@inf.unibz.it, xiao@inf.unibz.it | [b] Birkbeck, University of London, UK. E-mail: roman@dcs.bbk.ac.uk | [c] IBM TJ Watson, US. E-mail: mrodrig@us.ibm.com

Correspondence: [*] Corresponding author. E-mail: calvanese@inf.unibz.it.

Abstract: We present Ontop, an open-source Ontology-Based Data Access (OBDA) system that allows for querying relational data sources through a conceptual representation of the domain of interest, provided in terms of an ontology, to which the data sources are mapped. Key features of Ontop are its solid theoretical foundations, a virtual approach to OBDA, which avoids materializing triples and is implemented through the query rewriting technique, extensive optimizations exploiting all elements of the OBDA architecture, its compliance to all relevant W3C recommendations (including SPARQL queries, R2RML mappings, and OWL 2 QL and RDFS ontologies), and its support for all major relational databases.

Keywords: Ontop, OBDA, databases, RDF, SPARQL, ontologies, R2RML, OWL

DOI: 10.3233/SW-160217

Journal: Semantic Web, vol. 8, no. 3, pp. 471-487, 2017