Diego Calvanese is visiting Webdam from Monday 23 February to Friday 27 February 2009. He is a professor at the Faculty of Computer Science at the Free University of Bozen-Bolzano.
He will present his work on Ontology-Based Data Access and Data Integration Wednesday at 2:00pm in the meeting room N107.
Title : Ontology-Based Data Access and Data Integration
Summary :Ontologies provide a conceptualization of a domain of interest. Nowadays, they are typically represented in terms of Description Logics, and are seen as the key technology used to describe the semantics of information at various sites. The idea of using ontologies as a conceptual view over data repositories is becoming more and more popular. In order for this idea to become widespread in standard applications, it is fundamental that the conceptual layer through which the underlying data layer is accessed does not introduce a significant overhead in dealing with the data. Based on these observations, in recent years techniques to access data sources through a conceptual layer built on top of them have been developed, and the computational complexity of answering queries over ontologies, measured in the size of the underlying data, has been studied. In the talk we will present the general ideas underlying ontology based data access and integration, and will discuss the tradeoff between expressive power of the ontology language, and efficiency in query processing. Specifically, we will address the possibility of delegating query processing in ontology based data access to a relational database engine and will also present the QuOnto system, implementing this approach.