Knowledge integration through semantic query rewriting

Data integration is the process of assembling pieces of data from different sources to provide the user with complete information about a given domain. In this scenario, query rewriting mediation has some advantages over the more commonly adopted data warehousing. In this paper we show that, if formal ontologies are used to describe nodes schemas, ontological reasoning can be used in schema mapping and the system can automatically translate global queries into subqueries to be delegated to other nodes. We present ONTO Force as a prototype of knowledge network platform, that uses an extension of SPARQL language for knowledge management.