This paper presents a novel mediation-based query answering approach which allows users (1) to reuse their own predefined queries to retrieve information properly from their local data source, and (2) to reformulate those queries in terms of remote data sources in order to obtain additional relevant information. The problem of structural diversity in XML design (e.g. nesting discrepancy and backward paths) makes it difficult to reformulate the queries. Therefore, we highlight the importance of precise query rewriting using composite concepts and relations of the mediated schema. Our experimental evaluations on real application datasets show that our approach effectively obtains correct answers over a broad diversity of schemas.
展开▼
