Existential Rules: A Graph-Based View

Marie-Laure Mugnier 1
1 GRAPHIK - Graphs for Inferences on Knowledge
LIRMM - Laboratoire d'Informatique de Robotique et de Microélectronique de Montpellier, CRISAM - Inria Sophia Antipolis - Méditerranée
Abstract : We consider rules that allow to assert the existence of new individuals, an ability called value invention in databases. These rules are of the form body --> head, where the body and the head are function-free conjunctions of atoms, and variables that occur only in the head are existentially quantified, hence their name existential rules. Existential rules have long been studied in databases as high-level constraints called tuple generating dependencies. Recently, there has been renewed interest for these rules in the context of ontology-based data access (OBDA), a new paradigm that seeks to exploit the semantics encoded in ontologies while querying data. The deductive database language Datalog could be seen as a natural candidate for expressing ontological knowledge in this context, however its limitation is that it does not allow for value invention, since all variables in a rule head necessarily occur in the rule body. Value invention has been recognized as a necessary prerequisite in an open-world perspective, where all individuals are not known a priori. It is in particular a feature of description logics (DLs), well-known languages dedicated to ontological representation and reasoning. This prerequisite motivated the recent extension of Datalog to existential rules, which gave rise to the Datalog +/- formalism. In this talk, we present a graph view of the existential rule framework and some related results.
Type de document :
Communication dans un congrès
Pablo Barceló and Reinhard Pichler. 2nd International Workshop on Datalog 2.0, Vienne, Austria. Springer, pp.21-26, 2012, LNCS. 〈http://www.dbai.tuwien.ac.at/datalog2.0/〉
Liste complète des métadonnées

https://hal-lirmm.ccsd.cnrs.fr/lirmm-00763474
Contributeur : Marie-Laure Mugnier <>
Soumis le : lundi 10 décembre 2012 - 22:15:08
Dernière modification le : jeudi 24 mai 2018 - 15:59:22

Identifiants

  • HAL Id : lirmm-00763474, version 1

Collections

Citation

Marie-Laure Mugnier. Existential Rules: A Graph-Based View. Pablo Barceló and Reinhard Pichler. 2nd International Workshop on Datalog 2.0, Vienne, Austria. Springer, pp.21-26, 2012, LNCS. 〈http://www.dbai.tuwien.ac.at/datalog2.0/〉. 〈lirmm-00763474〉

Partager

Métriques

Consultations de la notice

214