On the parameterised complexity of tree-shaped ontology-mediated queries in OWL2QL
Bienvenu, M. and Kikot, S. and Kontchakov, Roman and Ryzhikov, Vladislav and Zakharyaschev, Michael (2017) On the parameterised complexity of tree-shaped ontology-mediated queries in OWL2QL. In: Artale, A. and Glimm, B. and Kontchakov, Roman (eds.) DL 2017: International Workshop on Description Logics. CEUR Workshop Proceedings 1879. CEUR.
Abstract
We discuss the parameterised complexity of answering tree-shaped ontology-mediated queries (OMQs) in OWL2QL under various restrictions on their ontologies and conjunctive queries (CQs). In particular, we construct an ontology τ such that answering OMQs (τ, q) with tree-shaped CQs q is W[1]- hard if the number of leaves in q is regarded as the parameter. The number of leaves has previously been identified as an important characteristic of CQs as bounding it leads to tractable OMQ answering. Our result shows that treating it as a parameter does not make the problem fixed-parameter tractable, even for a fixed ontology.
Metadata
Item Type: | Book Section |
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Additional Information: | 30th International Workshop on Description Logics, DL 2017; Montpellier; France; 18 July 2017 through 21 July 2017 |
Keyword(s) / Subject(s): | Data description, Forestry, Formal languages |
School: | Birkbeck Faculties and Schools > Faculty of Science > School of Computing and Mathematical Sciences |
Depositing User: | Administrator |
Date Deposited: | 06 Sep 2017 14:07 |
Last Modified: | 09 Aug 2023 12:42 |
URI: | https://eprints.bbk.ac.uk/id/eprint/19606 |
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