Expressive Approximations in DL-Lite Ontologies

  • Elena Botoeva
  • Diego Calvanese
  • Mariano Rodriguez-Muro
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 6304)


Ontology based data access (OBDA) is concerned with providing access to typically very large data sources through a mediating conceptual layer that allows one to improve answers to user queries by taking into account domain knowledge. In the context of OBDA applications, an important issue is that of reusing existing domain ontologies. However, such ontologies are often formulated in expressive languages, which are incompatible with the requirements of efficiently accessing large amounts of data. Approximation of such ontologies by means of less expressive ones has been proposed as a possible solution to this problem. In this work we present our approach to semantic (as opposed to syntactic) approximation of OWL 2 TBoxes by means of TBoxes in \(Dl-Lite_{\mathcal A}\). The point of interest in \(Dl-Lite_{\mathcal A}\) approximations is capturing entailments involving chains of existential role restrictions, which can play an essential role in query answering. The presence of TBox assertions involving existential chains affects query answering by enriching the number of obtained rewritings, and hence allows us to cope better with incomplete information about object and data properties. We provide an approximation algorithm and show its soundness and completeness. We also discuss the implementation of the algorithm.


Description Logic Conservative Extension Query Answering Complete Approximation Concept Inclusion 
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.


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© Springer-Verlag Berlin Heidelberg 2010

Authors and Affiliations

  • Elena Botoeva
    • 1
  • Diego Calvanese
    • 1
  • Mariano Rodriguez-Muro
    • 1
  1. 1.KRDB Research CentreFree University of Bozen-BolzanoItaly

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