Interfacing Parallel Applications and Parallel Databases

The use of parallel database systems to deliver high performance has become quite common. Although queries submitted to these database systems are executed in parallel, the interaction between applications and current parallel database systems is serial. As the complexity of the applications and the amount of data they access increases, the need to parallelize applications also increases. In this parallel application environment, a serial interface to the database could become the bottleneck in the performance of the application. Hence, parallel database systems should support interfaces that allow the applications to interact with the database system in parallel. We present a taxonomy of such parallel interfaces, namely the Single Coordinator, Multiple Coordinator, Hybrid Parallel, and Pure Parallel interfaces. Furthermore, we discuss how each of these interfaces can be realized and in the process introduce new constructs that enable the implementation of the interfaces. We also qualitatively evaluate each of the interfaces with respect to their restrictiveness and performance impact.