When Database Systems Meet the Grid
  We illustrate the benefits of combining database systems and Grid technologies for data-intensive applications. Using a cluster of SQL servers, we reimplemented an existing Grid application that finds galaxy clusters in a large astronomical database. The SQL implementation runs an order of magnitude faster than the earlier Tcl-C-file-based implementation. We discuss why and how Grid applications can take advantage of database systems. 
Maria A. Nieto-Santisteban, Alexander S. Szalay, Aniruddha R. Thakar,   William J. O'Mullane, Jim Gray, James Annis