PAGODA

Practical Algorithms for Ontology-based Data Access

PAGODA is a research project funded by the French National Research Agency (ANR).

Project ID: ANR #12 JS02 007 01, Programme JCJC
Start date: January 1st, 2013
Duration: 48 months
Hosting institution: Université Paris-Sud

The project is led by Meghyn Bienvenu, a CNRS researcher at the LIRMM laboratory (formerly at LRI).

Project Objectives

Ontology-based data access (OBDA) is a new paradigm in data management that seeks to exploit the semantic knowledge expressed in ontologies when querying data. Ontologies can improve query answering by enriching the vocabulary of data sources, relating the vocabularies of different data sources during data integration, and helping overcome data incompleteness by allowing inference of new facts. OBDA has the potential to revolutionize health data management by allowing sophisticated semantic querying of patient data; it is also poised to have a major impact in the life sciences by facilitating the exchange of experimental data among researchers. More generally, the semantically-enriched querying capabilities and seamless data integration which are the hallmarks of the OBDA approach are relevant to practically every application area which currently relies on relational databases, notably, enterprise information systems. However, before OBDA can be widely adopted in applications, some important foundational challenges need to be addressed. This project is centered on the following two challenges:

Scalability: Modern-day relational database management systems benefit from decades of research on querying algorithms and optimizations. By contrast, ontology-based data access is a young area of study, and despite important recent advances, including the identification of interesting tractable ontology languages, much work remains to be done in designing scalable OBDA query answering algorithms.

Handling data inconsistencies: In real-world applications involving large amounts of data or multiple data sources, it is very likely that the data will be inconsistent with the ontology, rendering standard querying algorithms useless (as everything is entailed from a contradiction). Appropriate mechanisms for dealing with inconsistent data are thus crucial to the successful use of OBDA in practice, yet have been little explored thus far.

The primary aim of this project is to help address these challenges by developing novel query answering algorithms and practical methods for handling inconsistent data.

Participants

The project brings together researchers from four sites:

Montpellier
Jean-François Baget (INRIA researcher, LIRMM, INRIA)
Meghyn Bienvenu (CNRS researcher, LIRMM, INRIA)
Stathis Delivorias (PhD student, LIRMM, INRIA)
Marie-Laure Mugnier (professor, LIRMM, INRIA)
Federico Ulliana (associate professor, LIRMM, INRIA)
Swan Rocher (PhD student, LIRMM, INRIA)

Paris-Saclay
Michaël Thomazo (INRIA researcher, LIX, INRIA)
Camille Bourgaux (PhD student, LRI)

Lannion (Brittany)
François Goasdoué (professor, IRISA)

Grenoble
Olivier Palombi (professor of anatomy and neurosurgeon, LADAF, LJK )
Marie-Christine Rousset (professor, LIG)

Former participants: Mélanie König, Despoina Trivela

Software and ontology development

CQAPri system and benchmark for inconsistency-tolerant query answering with DL-Lite ontologies

My Corporis Fabrica (MyCF) Anatomy Ontology and Embryo Ontology

Publications

2016

Meghyn Bienvenu, Carsten Lutz, and Frank Wolter:
Query and Predicate Emptiness in Description Logics.
To appear in Journal of Artificial Intelligence Research (JAIR).

Meghyn Bienvenu and Riccardo Rosati:
Query-based comparison of mappings in ontology-based data access
Accepted for publication in the Proceedings of the 15th International Conference on Principles of Knowledge Representation and Reasoning (KR'16).

Jean-Francois Baget, Salem Benferhat, Zied Bouraoui, Madalina Croitoru, Mugnier Marie-Laure, Odile Papini, Swan Rocher, and Karim Tabia:
A General Modifier-based Framework for Inconsistency-Tolerant Query Answering
Accepted for publication in the Proceedings of the 15th International Conference on Principles of Knowledge Representation and Reasoning (KR'16).

Meghyn Bienvenu, Camille Bourgaux, and François Goasdoué:
Explaining Inconsistency-Tolerant Query Answering over Description Logic Knowledge Bases
Proceedings of the 30th AAAI Conference on Artificial Intelligence (AAAI'16).

Marie-Laure Mugnier, Marie-Christine Rousset, and Federico Ulliana
Ontology-Mediated Queries for NOSQL Databases
Proceedings of the 30th AAAI Conference on Artificial Intelligence (AAAI'16).

2015

Jean-François Baget, Meghyn Bienvenu, Marie-Laure Mugnier, Swan Rocher:
Combining Existential Rules and Transitivity: Next Steps
Proceedings of the 24th AAAI International Joint Conference on Artificial Intelligence (IJCAI'15), 2720-2726.
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Mélanie König, Michel Leclère, Marie-Laure Mugnier:
Query Rewriting for Existential Rules with Compiled Preorder
Proceedings of the 24th AAAI International Joint Conference on Artificial Intelligence (IJCAI'15), 3106-3112.
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Meghyn Bienvenu, Stanislav Kikot, Vladimir V. Podolskii:
Tree-like Queries in OWL 2 QL: Succinctness and Complexity Results
Proceedings of the 30th Annual ACM/IEEE Symposium on Logic in Computer Science (LICS'15), 317-328.
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Meghyn Bienvenu, Magdalena Ortiz:
Ontology-Mediated Query Answering with Data-Tractable Description Logics
Proceedings of the 11th Reasoning Web Summer School (RW 2015).
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Federico Ulliana, Marie-Christine Rousset:
Extracting Bounded-Level Modules from Deductive RDF Triplestores
Proceedings of the 29th AAAI Conference on Artificial Intelligence (AAAI'15).
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Mélanie König, Michel Leclère, Marie-Laure Mugnier, Michaël Thomazo:
Sound, Complete and Minimal UCQ-Rewriting for Existential Rules
Semantic Web Journal (SWJ), 6(5): 451-475.
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Meghyn Bienvenu, Magdalena Ortiz, and Mantas Simkus:
Regular Path Queries in Lightweight Description Logics: Complexity and Algorithms
Journal of Artificial Intelligence Research (JAIR), 53: 315-374.
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Pierre-Yves Rabattu, Benoit Massé, Federico Ulliana, Marie-Christine Rousset, Damien Rohmer, Jean-Claude Léon and Olivier Palombi:
My Corporis Fabrica Embryo: An ontology-based 3D spatio-temporal modeling of human embryo development
Journal of Biomedical Semantics (JBS), 6:36.
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2014

Olivier Palombi, Federico Ulliana, Valentin Favier, Jean-Claude Leon, Marie-Christine Rousset:
My Corporis Fabrica: An Ontology-based Tool for Reasoning and Querying on Complex Anatomical Models
Journal of Biomedical Semantics 5 : 20.
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Meghyn Bienvenu, Diego Calvanese, Magdalena Ortiz, and Mantas Simkus:
Nested Regular Path Queries in Description Logics
Proceedings of the 14th International Conference on Principles of Knowledge Representation and Reasoning (KR'14).
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Jean-François Baget, Fabien Garreau, Marie-Laure Mugnier and Swan Rocher:
Extending Acyclicity Notions for Existential Rules
Proceedings of the 21st European Conference on Artificial Intelligence (ECAI'14).
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Meghyn Bienvenu, Camille Bourgaux, François Goasdoué:
Querying Inconsistent Description Logic Knowledge Bases under Preferred Repair Semantics
Proceedings of the 28th AAAI Conference on Artificial Intelligence (AAAI'14).
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Meghyn Bienvenu, Balder ten Cate, Carsten Lutz, and Frank Wolter:
Ontology-based Data Access: A Study through Disjunctive Datalog, CSP, and MMSNP.
ACM Transactions on Database Systems (TODS), 39(4): 33.
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2013

Meghyn Bienvenu, Balder ten Cate, Carsten Lutz, and Frank Wolter:
Ontology-based Data Access: A Study through Disjunctive Datalog, CSP, and MMSNP.
Proceedings of the 32nd International Conference on the Principles of Database Systems (PODS'13).
download (extended version)

Meghyn Bienvenu, Carsten Lutz, and Frank Wolter:
First Order-Rewritability of Atomic Queries in Horn Description Logics
Proceedings of the 23rd International Joint Conference on Artificial Intelligence (IJCAI'13).
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Meghyn Bienvenu, Magdalena Ortiz, and Mantas Simkus:
Conjunctive Regular Path Queries in Lightweight Description Logics
Proceedings of the 23rd International Joint Conference on Artificial Intelligence (IJCAI'13).
download (extended version)

Meghyn Bienvenu, Magdalena Ortiz, Mantas Simkus, and Guohui Xiao:
Tractable Queries for Lightweight Description Logics
Proceedings of the 23rd International Joint Conference on Artificial Intelligence (IJCAI'13).
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Meghyn Bienvenu and Riccardo Rosati:
Tractable Approximations of Consistent Query Answering for Robust Ontology-based Data Access
Proceedings of the 23rd International Joint Conference on Artificial Intelligence (IJCAI'13).
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Michaël Thomazo:
Compact Rewritings for Existential Rules
Proceedings of the 23rd International Joint Conference on Artificial Intelligence (IJCAI'13).
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Mélanie König, Michel Leclère, Marie-Laure Mugnier, Michaël Thomazo:
On the Exploration of the Query Rewriting Space with Existential Rules
Proceedings of the 7th International Conference on Web Reasoning and Rule Systems (RR'13).
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