Service-based data integration using OGSA-DQP and OGSA-WebDB

OGSA-DQP is a service-based distributed query processor that is able to execute queries over data services and combine data integration with data analysis by invoking Web services. OGSA-DQP currently supports only one type of data source, relational databases wrapped using OGSA-DAI (a middleware tool that exposes XML or relational database management systems as Grid services). OGSA-WebDB is another middleware tool based on OGSA-DAI that exposes Web databases via the OGSA-DAI interface. The prevalence of XML encoded data and Web-accessible resources means that it is desirable to extend the current functionality of OGSA-DQP to provide support for such resources. This paper presents an extension to OGSA-DQP that allow queries over relational, XML and Web databases wrapped by OGSA-DAI and OGSA-WebDB. An application is presented that illustrates how these features complement each other to provide data integration and analysis in service-based Grids. Experimental results are presented that investigate the benefit of the approach within the application.