Answering SPARQL Queries over Databases under OWL 2 QL Entailment Regime

Kontchakov R.; Rezk M.; Rodríguez-Muro M.; Xiao G.; M. Zakharyaschev

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Answering SPARQL Queries over Databases under OWL 2 QL Entailment Regime

Ch. 35. P. 552–567.

Kontchakov R., Rezk M., Rodríguez-Muro M., Xiao G., Zakharyaschev M.

We present an extension of the ontology-based data access platform Ontop that supports answering SPARQL queries under the OWL 2 QL direct semantics entailment regime for data instances stored in relational databases. On the theoretical side, we show how any input SPARQL query, OWL 2 QL ontology and R2RML mappings can be rewritten to an equivalent SQL query solely over the data. On the practical side, we present initial experimental results demonstrating that by applying the Ontop technologies—the tree-witness query rewriting, T-mapping optimisations using SQL expressivity and database integrity constraints—the system produces scalable SQL queries.

Language: English

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Keywords: SPARQL SQL query optimization

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The Semantic Web – ISWC 2014. Proceedings of 13th International Semantic Web Conference, Part I

Cham: Springer, 2014.

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