Answering SPARQL queries over databases under OWL 2 QL entailment regime

R Kontchakov, M Rezk, M Rodriguez-Muro… - International Semantic …, 2014 - Springer
We present an extension of the ontology-based data access platform Ontop that supports
answering SPARQL queries under the OWL 2 QL direct semantics entailment regime for …

Query rewriting and optimization for ontological databases

G Gottlob, G Orsi, A Pieris - ACM Transactions on Database Systems …, 2014 - dl.acm.org
Ontological queries are evaluated against a knowledge base consisting of an extensional
database and an ontology (ie, a set of logical assertions and constraints that derive new …

[HTML][HTML] The price of query rewriting in ontology-based data access

G Gottlob, S Kikot, R Kontchakov, V Podolskii… - Artificial Intelligence, 2014 - Elsevier
We give a solution to the succinctness problem for the size of first-order rewritings of
conjunctive queries in ontology-based data access with ontology languages such as OWL 2 …

An introduction to ontology-based query answering with existential rules

ML Mugnier, M Thomazo - Reasoning Web. Reasoning on the Web in the …, 2014 - Springer
The need for an ontological layer on top of data, associated with advanced reasoning
mechanisms able to exploit ontological knowledge, has been acknowledged in the …

Sound, complete and minimal UCQ-rewriting for existential rules

M König, M Leclère, ML Mugnier… - Semantic Web, 2015 - journals.sagepub.com
We address the issue of Ontology-Based Data Access, with ontologies represented in the
framework of existential rules, also known as Datalog±. A well-known approach involves …

Ontology-based data federation

Z Gu, D Lanti, A Mosca, G ** analysis in ontology-based data access
D Lembo, J Mora, R Rosati, DF Savo… - … Conference on Web …, 2014 - Springer
In this paper we study map** analysis in ontology-based data access (OBDA), providing
an initial set of foundational results for this problem. We start by defining general, language …

[PDF][PDF] On Bounded Positive Existential Rules.

M Leclère, ML Mugnier, F Ulliana - Description Logics, 2016 - lirmm.fr
We consider the existential rule framework, which generalizes Horn description logics. We
study and compare several boundedness notions in this framework. Our main result states …