Optimal nonrecursive datalog rewritings of linear TGDs and bounded (Hyper)Tree-width queries
Bienvenu, M. and Kikot, S. and Kontchakov, Roman and Ryzhikov, Vladislav and Zakharyaschev, Michael (2017) Optimal nonrecursive datalog rewritings of linear TGDs and bounded (Hyper)Tree-width queries. In: Artale, A. and Glimm, B. and Kontchakov, Roman (eds.) DL 2017: International Workshop on Description Logics. CEUR Workshop Proceedings 1879 1879. CEUR.
Abstract
Our concern is answering ontology-mediated queries (Ο q), whereΟ is a set of linear tgds and q a conjunctive query (CQ) of bounded hypertree width. Assuming that the arity of predicates is bounded, we show that polynomial-size nonrecursive Datalog rewritings can be constructed and executed in (i) LOGCFL for OMQs with ontologies of bounded existential depth; (ii) NL for OMQs with ontologies of bounded depth and CQs whose hypertree decompositions have a bounded number of leaves; (iii) LOGCFL for OMQs with acyclic CQs whose join trees have a bounded number of leaves.
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): | Forestry, Formal languages, Ontology |
School: | Birkbeck Faculties and Schools > Faculty of Science > School of Computing and Mathematical Sciences |
Depositing User: | Administrator |
Date Deposited: | 06 Sep 2017 14:05 |
Last Modified: | 09 Aug 2023 12:42 |
URI: | https://eprints.bbk.ac.uk/id/eprint/19605 |
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