Exposing heterogeneous data sources as SPARQL endpoints through an object-oriented abstraction

Abstract

The Web of Data vision raises the problem of how to expose existing data sources on the Web without requiring heavy manual work. In this paper, we present our approach to facilitate SPARQL queries over heterogeneous data sources. We propose the use of an object-oriented abstraction which can be automatically mapped and translated into an ontological one; this approach, on the one hand, helps data managers to disclose their sources without the need of a deep understanding of Semantic Web technologies and standards and, on the other hand, takes advantage of object-relational mapping (ORM) technologies and tools to deal with different types of data sources (relational DBs, but also XML sources, object-oriented DBs, LDAP, etc.). We introduce both the theoretical foundations of our solution, with the analysis of the relation and mapping between SPARQL algebra and monoid comprehension calculus (the formalism behind object queries), and the implementation we are using to prove the feasibility and the benefits of our approach and to compare it with alternative methods. © 2008 Springer Berlin Heidelberg.