Consistent Query Answering over Description Logic Ontologies

Abstract

Description Logics (DLs) have been widely used in the last years as formal language for specifying ontologies. In several contexts, as ontology-based data integration, it may frequently happen that data contradict the intensional knowledge provided by the ontology through which they are accessed, which therefore may result inconsistent. In this paper, we analyze the problem of consistent query answering (CQA) over DL ontologies, i.e., the problem of providing meaningful answers to queries posed over inconsistent ontologies. We provide inconsistency-tolerant semantics for DLs, and study the computational complexity of CQA under such semantics for the case of conjunctive queries posed over ontologies specified in DL-LiteF , a DL specifically tailored to deal with large amounts of data. We show that the above problem is coNP-complete w.r.t. data complexity. We then study the problem of consistent instance checking for DL-LiteF ontologies, i.e., the instance checking problem considered under our inconsistency-tolerant semantics, and we show that such problem is in PTIME w.r.t. data complexity.

DOI: 10.1007/978-3-540-72982-2_14

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Cite this paper

@inproceedings{Lembo2007ConsistentQA, title={Consistent Query Answering over Description Logic Ontologies}, author={Domenico Lembo and Marco Ruzzi}, booktitle={Description Logics}, year={2007} }