Experiences Running OGSA-DQP Queries against a Heterogeneous Distributed Scientific Database

This paper explores the use of emerging Grid technologies for the manipulation of a scientific dataset with complex schema. We focus on the potential of a well-known grid middleware-OGSA-DQP-for querying such datasets. In particular, we investigate running OGSA-DQP queries against SQL Server and Oracle database to access data in a complex schema of a real scientific database-the Sloan digital sky survey (SDSS) database. We used two common databases which support complex schemas and very large datasets: SQL Server and Oracle. The paper briefly provides the background information on the SDSS database. It then examines the running of a few OGSADQP queries and the query plans. Various join queries run successfully through OGSA-DQP after we optimized the implementation of some of the OGSA-DQP operations.