Active discovery based query federation over the web of linked data

For many applications over the Web of Linked Data, it is a key challenge to access multiple distributed data sources in an integrated and transparent way. In traditional federated query, data from unknown data sources are ignored, which in turn leads to a poor recall of the query result. Furthermore, due to the openness of the Web of Linked Data, it is very difficult to know in advance all data sources in this Web. To overcome these problems we present a novel approach to query the Web of Linked Data. The main idea of our approach is to discover query services that might be used to answer a query during the query execution itself. Our approach can be independently used or the complement of traditional federated query for querying this Web of Data. We provide a prototype implementation and performance evaluation of our work. The experiment shows the feasibility of our approach.