Efficient ontology-based data management

Type de soutenance
Thèse
Date de début
Date de fin
Lieu
IRISA Lannion
Salle
020G - ENSSAT LANNION
Orateur
Wafaa EL HUSSEINI (SHAMAN)
Sujet

Ontology-mediated query answering (OMQA) consists in asking database queries on knowledge bases (KBs); a KB is a set of facts called a database, which is described by a  domain knowledge called an ontology. A main OMQA technique is FO-rewriting, which reformulates a query asked on a KB \wrt to the KB's ontology; query answers are then computed through the relational evaluation of the query reformulation on the KB's database. Essentially, because FO-rewriting compiles the domain knowledge relevant to queries into their reformulations, query reformulations may be complex and their optimization is the crux of efficiency. We devise a novel optimization framework for a large set of OMQA settings that enjoy FO-rewriting: conjunctive queries, i.e., the core select-project-join queries, asked on KBs expressed in datalog$\pm$ and existential rules, description logic and OWL, or RDF/S. We optimize the query reformulations produced by any state-of-the-art algorithm for FO-rewriting by computing rapidly, using a KB's database summary, simpler queries with same answers that can be evaluated faster by DBMSs. We show on a well-established OMQA benchmark that time performance is significantly improved by our optimization framework in general, up to three orders of magnitude.

Thèse diffusée en visio conférence. Les liens de connexion seront à demander à francois [*] goasdoueatirisa [*] fr

 

Composition du jury
Rapporteurs avant soutenance:
Nicole BIDOIT-TOLLU : Professeure des Universités émérite, Université Paris-Saclay
Mohand-Saïd HACID : Professeur des Universités, Université Claude Bernard Lyon 1

Examinateurs:
Nicole BIDOIT-TOLLU : Professeure des Universités émérite, Université Paris-Saclay
David GROSS-AMBLARD : Professeur des Universités, Université de Rennes
Mohand-Saïd HACID : Professeur des Universités, Université Claude Bernard Lyon 1
Ioana MANOLESCU : Directrice de Recherche, INRIA Saclay
Farouk TOUMANI : Professeur des Universités, Université Clermont-Auvergne

Directeur de thèse:
François GOASDOUÉ : Professeur des Universités, Université de Rennes

Encadrante de thèse :
Hélène JAUDOIN: Maîtresse de Conférences, Université de Rennes