Computing FO-Rewritings in \(\mathcal{EL}\) in Practice: From Atomic to Conjunctive Queries

  • Peter Hansen
  • Carsten LutzEmail author
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 10587)


A prominent approach to implementing ontology-mediated queries (OMQs) is to rewrite into a first-order query, which is then executed using a conventional SQL database system. We consider the case where the ontology is formulated in the description logic \(\mathcal{EL}\) and the actual query is a conjunctive query and show that rewritings of such OMQs can be efficiently computed in practice, in a sound and complete way. Our approach combines a reduction with a decomposed backwards chaining algorithm for OMQs that are based on the simpler atomic queries, also illuminating the relationship between first-order rewritings of OMQs based on conjunctive and on atomic queries. Experiments with real-world ontologies show promising results.



We acknowledge support by ERC grant 647289 ‘CODA’.


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Copyright information

© Springer International Publishing AG 2017

Authors and Affiliations

  1. 1.University of BremenBremenGermany

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