An Introduction to Ontology-Based Query Answering with Existential Rules

  • Marie-Laure Mugnier
  • Michaël Thomazo
Part of the Lecture Notes in Computer Science book series (LNCS, volume 8714)


The need for an ontological layer on top of data, associated with advanced reasoning mechanisms able to exploit ontological knowledge, has been acknowledged in the database, knowledge representation and Semantic Web communities. We focus here on the ontology-based data querying problem, which consists in querying data while taking ontological knowledge into account. To tackle this problem, we consider a logical framework based on existential rules, also called Datalog±.

In this course, we introduce fundamental notions on ontology-based query answering with existential rules. We present basic reasoning techniques, explain the relationships with other formalisms such as lightweight description logics, and review decidability results as well as associated algorithms. We end with ongoing research and some challenging issues.


Description Logic Horn Clause Conjunctive Query Query Answering Good Assignment 
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 International Publishing Switzerland 2014

Authors and Affiliations

  • Marie-Laure Mugnier
    • 1
  • Michaël Thomazo
    • 2
  1. 1.Université Montpellier 2France
  2. 2.TU DresdenGermany

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