QueryPIE: Backward Reasoning for OWL Horst over Very Large Knowledge Bases

  • Jacopo Urbani
  • Frank van Harmelen
  • Stefan Schlobach
  • Henri Bal
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 7031)


Both materialization and backward-chaining as different modes of performing inference have complementary advantages and disadvantages.

Materialization enables very efficient responses at query time, but at the cost of an expensive up front closure computation, which needs to be redone every time the knowledge base changes. Backward-chaining does not need such an expensive and change-sensitive precomputation, and is therefore suitable for more frequently changing knowledge bases, but has to perform more computation at query time.

Materialization has been studied extensively in the recent semantic web literature, and is now available in industrial-strength systems. In this work, we focus instead on backward-chaining, and we present an hybrid algorithm to perform efficient backward-chaining reasoning on very large datasets expressed in the OWL Horst (pD*) fragment.

As a proof of concept, we have implemented a prototype called QueryPIE (Query Parallel Inference Engine), and we have tested its performance on different datasets of up to 1 billion triples. Our parallel implementation greatly reduces the reasoning complexity of a naive backward-chaining approach and returns results for single query-patterns in the order of milliseconds when running on a modest 8 machine cluster.

To the best of our knowledge, QueryPIE is the first reported backward-chaining reasoner for OWL Horst that efficiently scales to a billion triples.


Input Pattern Query Time Query Pattern Triple Pattern Triple Store 
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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Copyright information

© Springer-Verlag Berlin Heidelberg 2011

Authors and Affiliations

  • Jacopo Urbani
    • 1
  • Frank van Harmelen
    • 1
  • Stefan Schlobach
    • 1
  • Henri Bal
    • 1
  1. 1.Department of Computer ScienceVrije Universiteit AmsterdamThe Netherlands

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