P2P schema-mapping over network-bound XML data

The rise in availability of web-based data sources has led to new challenges in data integration systems for obtaining decentralized, wide-scale sharing of data preserving semantics. In this paper, we present a framework for integrating heterogeneous XML data sources distributed over a large-scale, highly dynamic network of autonomous nodes. We highlight a query reformulation algorithm to combine and query-distributed XML databases through a decentralized point-to-point mediation process among the different data sources by using P2P schema-mappings. More precisely, our integration model is based on path-to-path mappings, using the XPath language. We demonstrate the usefulness and scalability of our ideas and algorithms with a detailed set of experiments. Finally, we discuss our experience implementing the above-cited query reformulation algorithm as a Web service within the GDIS system, a service-based Grid architecture. We have evaluated GDIS on several real-world schemas with promising results. Copyright (C) 2010 John Wiley & Sons, Ltd.