Abstract
Given a source relational database, a target OWL ontology and a mapping from the source database to the target ontology, Ontology-Based Data Access (OBDA) concerns answering queries over the target ontology using these three components. This paper presents the development of UltrawrapOBDA, an OBDA system comprising bidirectional evaluation; that is, a hybridization of query rewriting and materialization. We observe that by compiling the ontological entailments as mappings, implementing the mappings as SQL views and materializing a subset of the views, the underlying SQL optimizer is able to reduce the execution time of a SPARQL query by rewriting the query in terms of the views specified by the mappings. To the best of our knowledge, this is the first OBDA system supporting ontologies with transitivity by using SQL recursion. Our contributions include: (1) an efficient algorithm to compile ontological entailments as mappings; (2) a proof that every SPARQL query can be rewritten into a SQL query in the context of mappings; (3) a cost model to determine which views to materialize to attain the fastest execution time; and (4) an empirical evaluation comparing with a state-of-the-art OBDA system, which validates the cost model and demonstrates favorable execution times.
Keywords
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.
Download to read the full chapter text
Chapter PDF
Similar content being viewed by others
References
Allemang, D., Hendler, J.: Semantic Web for the Working Ontologist: Effective Modeling in RDFS and OWL. Morgan Kaufmann Publishers Inc. (2008)
Angles, R., Gutierrez, C.: The expressive power of sparql. In: Sheth, A.P., Staab, S., Dean, M., Paolucci, M., Maynard, D., Finin, T., Thirunarayan, K. (eds.) ISWC 2008. LNCS, vol. 5318, pp. 114–129. Springer, Heidelberg (2008)
Arenas, M., Barceló, P., Libkin, L., Murlak, F.: Foundations of Data Exchange. Cambridge University Press (2014)
Arenas, M., Bertails, A., Prud’hommeaux, E., Sequeda, J.: Direct mapping of relational data to RDF. W3C Recomendation (September 27, 2012)
Baader, F., Calvanese, D., McGuinness, D.L., Nardi, D., Patel-Schneider, P.F. (eds.): The Description Logic Handbook. Cambridge University Press (2003)
Bizer, C., Schultz, A.: The berlin sparql benchmark. Int. J. Semantic Web Inf. Syst. 5(2), 1–24 (2009)
Brickley, D., Guha, R.: RDF vocabulary description language 1.0: RDF schema. W3C recommendation (February 2004)
Calvanese, D., De Giacomo, G., Lembo, D., Lenzerini, M., Rosati, R.: Data complexity of query answering in description logics. Artif. Intell. 195, 335–360 (2013)
Chebotko, A., Lu, S., Fotouhi, F.: Semantics preserving sparql-to-sql translation. Data Knowl. Eng. 68(10), 973–1000 (2009)
Dantsin, E., Eiter, T., Gottlob, G., Voronkov, A.: Complexity and expressive power of logic programming. ACM Comput. Surv. 33(3), 374–425 (2001)
Das, S., Sundara, S., Cyganiak, R.: R2RML: RDB to RDF mapping language. W3C Recomendation (September 27, 2012)
DeWitt, D.J.: The wisconsin benchmark: Past, present, and future. In: The Benchmark Handbook, pp. 119–165 (1991)
Gupta, A., Mumick, I.S.: Materialized Views: Techniques, Implementations, and Applications. MIT Press (1999)
Halevy, A.Y.: Answering queries using views: A survey. VLDB J. 10(4), 270–294 (2001)
Lenzerini, M.: Data integration: A theoretical perspective. In: PODS, pp. 233–246 (2002)
Lutz, C., Seylan, İ., Toman, D., Wolter, F.: The combined approach to OBDA: Taming role hierarchies using filters. In: Alani, H., et al. (eds.) ISWC 2013, Part I. LNCS, vol. 8218, pp. 314–330. Springer, Heidelberg (2013)
Motik, B., Grau, B.C., Horrocks, I., Wu, Z., amd Carsten Lutz, A.F.: OWL 2 web ontology language profiles, 2nd edn. W3C recommendation (December 2012)
Muñoz, S., Pérez, J., Gutierrez, C.: Simple and efficient minimal RDFS. J. Web Sem. 7(3), 220–234 (2009)
Ortiz, M., Šimkus, M.: Reasoning and query answering in description logics. In: Eiter, T., Krennwallner, T. (eds.) Reasoning Web 2012. LNCS, vol. 7487, pp. 1–53. Springer, Heidelberg (2012)
Pérez, J., Arenas, M., Gutierrez, C.: Semantics and complexity of SPARQL. ACM Trans. Database Syst. 34(3) (2009)
Pinto, F.D., Lembo, D., Lenzerini, M., Mancini, R., Poggi, A., Rosati, R., Ruzzi, M., Savo, D.F.: Optimizing query rewriting in ontology-based data access. In: EDBT (2013)
Poggi, A., Lembo, D., Calvanese, D., Giacomo, G.D., Lenzerini, M., Rosati, R.: Linking data to ontologies. J. Data Semantics 10, 133–173 (2008)
Prud’hommeaux, E., Seaborne, A.: SPARQL query language for RDF. W3C Recommendation (January 15, 2008), http://www.w3.org/TR/rdf-sparql-query/
Rodríguez-Muro, M., Calvanese, D.: Dependencies: Making ontology based data access work in practice. In: AMW (2011)
Rodríguez-Muro, M., Kontchakov, R., Zakharyaschev, M.: Ontology-based data access: Ontop of databases. In: Alani, H., et al. (eds.) ISWC 2013, Part I. LNCS, vol. 8218, pp. 558–573. Springer, Heidelberg (2013)
Sequeda, J.F., Arenas, M., Miranker, D.P.: On directly mapping relational databases to RDF and OWL. In: WWW, pp. 649–658 (2012)
Sequeda, J.F., Miranker, D.P.: Ultrawrap: Sparql execution on relational data. J. Web Sem. 22, 19–39 (2013)
Weaver, J., Hendler, J.A.: Parallel materialization of the finite rdfs closure for hundreds of millions of triples. In: Bernstein, A., Karger, D.R., Heath, T., Feigenbaum, L., Maynard, D., Motta, E., Thirunarayan, K. (eds.) ISWC 2009. LNCS, vol. 5823, pp. 682–697. Springer, Heidelberg (2009)
Author information
Authors and Affiliations
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2014 Springer International Publishing Switzerland
About this paper
Cite this paper
Sequeda, J.F., Arenas, M., Miranker, D.P. (2014). OBDA: Query Rewriting or Materialization? In Practice, Both!. In: Mika, P., et al. The Semantic Web – ISWC 2014. ISWC 2014. Lecture Notes in Computer Science, vol 8796. Springer, Cham. https://doi.org/10.1007/978-3-319-11964-9_34
Download citation
DOI: https://doi.org/10.1007/978-3-319-11964-9_34
Publisher Name: Springer, Cham
Print ISBN: 978-3-319-11963-2
Online ISBN: 978-3-319-11964-9
eBook Packages: Computer ScienceComputer Science (R0)