How to Approximate Ontology-Mediated Queries

Haga, Anneke, Lutz, Carsten, Sabellek, Leif and Wolter, Frank
(2021) How to Approximate Ontology-Mediated Queries. In: International Conference on Principles of Knowledge Representation and Reasoning.

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We introduce and study several notions of approximation for ontology-mediated queries based on the description logics ALC and ALCI. Our approximations are of two kinds: we may (1) replace the ontology with one formulated in a tractable ontology language such as ELI or certain TGDs and (2) replace the database with one from a tractable class such as the class of databases whose treewidth is bounded by a constant. We determine the computational complexity and the relative completeness of the resulting approximations. (Almost) all of them reduce the data complexity from coNP-complete to PTime, in some cases even to fixed-parameter tractable and to linear time. While approximations of kind (1) also reduce the combined complexity, this tends to not be the case for approximations of kind (2). In some cases, the combined complexity even increases.

Item Type: Conference or Workshop Item (Unspecified)
Uncontrolled Keywords: cs.AI, cs.AI, cs.DB
Divisions: Faculty of Science and Engineering > School of Electrical Engineering, Electronics and Computer Science
Depositing User: Symplectic Admin
Date Deposited: 11 Oct 2021 07:59
Last Modified: 18 Jan 2023 21:27
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