OBDA Constraints for Effective Query Answering

  • Dag HovlandEmail author
  • Davide LantiEmail author
  • Martin RezkEmail author
  • Guohui XiaoEmail author
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 9718)


In Ontology Based Data Access (OBDA) users pose SPARQL queries over an ontology that lies on top of relational datasources. These queries are translated on-the-fly into SQL queries by OBDA systems. Standard SPARQL-to-SQL translation techniques in OBDA often produce SQL queries containing redundant joins and unions, even after a number of semantic and structural optimizations. These redundancies are detrimental to the performance of query answering, especially in complex industrial OBDA scenarios with large enterprise databases. To address this issue, we introduce two novel notions of OBDA constraints and show how to exploit them for efficient query answering. We conduct an extensive set of experiments on large datasets using real world data and queries, showing that these techniques strongly improve the performance of query answering up to orders of magnitude.


Database Schema Conjunctive Query SPARQL Query Triple Pattern Query Answering 
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.



This work is partially supported by the EU under IP project Optique (Scalable End-user Access to Big Data), grant agreement n. FP7-318338.


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Copyright information

© Springer International Publishing Switzerland 2016

Authors and Affiliations

  1. 1.University of OsloOsloNorway
  2. 2.Free University of Bozen-BolzanoBolzanoItaly

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