8th JAIST Advanced Lecture Series
A Study through Disjunctive Datalog, CSP, and MMSNP
Ontology-based Data Access
Frank Wolter

Univ. of Liverpool, Guest Prof. of JAIST
http://www.csc.liv.ac.uk/~frank/

リバプール大学 教授
北陸先端科学技術大学院大学 客員教授

2013-03-18, 15:10-17:10

K Lecture room 3・4

Ontology-based data access is concerned with querying incomplete data sources in the presence of domain-specific knowledge provided by an ontology. A central notion in this setting is that of an ontology-mediated query, which is a database query coupled with an ontology. In this paper, we study several classes of ontology-mediated queries, where the database queries are given as some form of conjunctive query and the ontologies are formulated in description logics or other relevant fragments of first-order logic, such as the guarded fragment and the unary-negation fragment. The contributions of the paper are three-fold.

First, we characterize the expressive power of ontology mediated queries in terms of fragments of disjunctive datalog.

Second, we establish intimate connections between ontology-mediated queries and constraint satisfaction problems (CSPs) and their logical generalization, MMSNP formulas.

Third, we exploit these connections to obtain new results regarding (i) first-order rewritability and datalogrewritability of ontology-mediated queries, (ii) P/NP dichotomies for ontology-mediated queries, and (iii) the query containment problem for ontology-mediated queries.

Based of PODS 2013 paper with Meghyn Bienvenu, Balder ten Cate and Carsten Lutz.

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Hiroakira Ono