International Journal of Computing Science and Information Technology (IJCSIT)
Middleware is an essential component for any type of distributed environment and network application. There are different middleware systems (like SQMD, DisCo, MOCHA, Open-Gate, OGSA-DAI, and OGSA-DQP) which give good performance, but most of them lack integrity constraints and scalability. Data integration using traditional database system or database gateway are not feasible or sufficient. Database middleware systems are used to integrate heterogeneous data sources distributed over network. There is a need to provide a mechanism which provides uniform view and access interface for heterogeneous data sets.