Mapping Management and Expressive Ontologies in Ontology-Based Data Access
20th International Conference on Knowledge Engineering and Knowledge Management (EKAW), November 19-20, 2016, Bologna, Italy
Ontology-Based Data Access (OBDA) has become a popular paradigm for overcoming the typical difficulties in accessing data stored in different kinds of legacy sources, by leveraging a conceptual representation of such data provided in terms of an ontology. OBDA relies on bridging database systems and technologies developed in the areas of Knowledge Representation and in the Semantic Web. The main mechanism for establishing such a bridge are RDF-to-database mappings, which allow one to create virtual views characterizing the content of the data sources and directly relate them to the terms in the ontology. In this tutorial: (i) We provide a general introduction to the principles and basic technologies for OBDA, relying on RDFS, the OWL~2~QL profile, and on the transformation of SPARQL into native database queries. (ii) We let participants practice such technologies in a hands-on session using Protégé and the OBDA system Ontop. (iii) We provide more insights into the theoretical foundations of OBDA, by analyzing query rewriting and the computational impact of ontologies on query answering. (iv) We continue with a further hands-on session on mapping engineering. (v) We provide an overview on the latest advancements in OBDA concerning non-relational (NoSQL) datasources, and approximation techniques.
- 9:00-10:30: Introduction to Ontology-Based Data Access (slides)
- 11:00-12:30: Hands-on Session 1: Basics of OBDA System Modeling and Usage (instructions)
- 14:00-15:00: Theoretical Foundations of OBDA (slides)
- 15:00-15:30: Latest Advancements in OBDA (slides)
- 16:00-17:30: Hands-on Session 2: Mapping Engineering and System Deployment (instructions)
- Basic knowledge in relational databases, RDF, and SPARQL;
- Background in description logics is preferable, but not strictly necessary.