A framework of Web service composition for distributed XML query evaluation

The generic architecture of Web services provides the Web data processing with a distributed and standardized infrastructure. It is indispensable to evaluate the composite services, e.g., the complex query evaluation on multiple data sources on the Web. In this paper, we propose a mediator framework as a middleware of Web service composition for distributed XML query processing on the heterogeneous data sources, regarding the system of the respective data source and the query processor as provider. In addition, lazy service processing as the optimization is proposed. Preliminary experiments and performance studies show our framework and the corresponding techniques are practical and efficient.