Integrated queries over a heterogeneously distributed scientific database using OGSA-DQP

In this paper we experiment with using the UNION ALL operator to make data integration queries over a version of the SDSS scientific Database, distributed using OGSA-DQP. The paper starts with background information on the SDSS database and the eScience technologies OGSA-DAI and OGSA-DQP. It recaps how we distributes a SDSS database across three sites. It then examines the running of several OGSA-DQP queries against the database. We discuss our experiences of using UNION ALL for integrating data results from data service resources based on heterogeneous underlying database management systems.