The SDCC framework for integrating existing algorithms for diverse data warehouse maintenance tasks

Recently proposed view maintenance algorithms tackle the problem of concurrent data updates happening at different autonomous information systems (ISs), whereas the EVE (Evolvable View Environment) system addresses the maintenance of a data warehouse (DW) after IS schema changes. The concurrency of schema changes and data updates still remains an unexplored problem, however. This paper provides a solution that guarantees concurrent view definition evolution and view extent maintenance of a DW defined over distributed ISs. For this problem, we introduce a framework called SDCC (Schema change and Data update Concurrency Control) system. SDCC integrates existing algorithms designed to address view maintenance subproblems (such as view extent maintenance after IS data updates, view definition evolution after IS schema changes, and view extent adaptation after view definition changes) into one system by providing protocols that enable them to correctly co-exist and collaborate. SDCC tracks any potential faulty updates of the DW caused by conflicting concurrent IS changes, and compensates for such conflicting updates by a local correction strategy called local compensation.