基于网格服务的半连接查询优化算法研究

随着网格计算技术的快速发展，其应用领域在不断扩大，然而，跨网络分布式数据的联合查询往往成为性能的瓶颈，因此文中从提高分布式数据的联合查询的效率出发，以网格计算这一新型web体系结构为技术平台，研究基于网格服务的查询优化目标、查询优化对象和查询优化策略。文中采用了应用非常广泛的启发式搜索算法来缩小策略空间这一优化策略，并在该策略的基础上提出了一种基于网格服务的2-way半连接查询优化算法，最后在网格计算环境下对该算法与一般的全连接算法做了实验对比，证明基于网格服务的2-way半连接查询优化算法可大大缩短查询响应时间。

Research of Semi-join Query Optimization Algorithm Based on Grid Service

With the rapid development of grid computing, it has been applied into a larger area, however, distributed data joint inquires across the network often becomes the bottleneck of performance, therefore, in order to improve efficiency of the joint inquires of distributed data, based on the new grid computing web system structure, research query optimization goal, query optimization objects and query optimization strategy based on grid services. It adopts the optimization strategy uses the very extensive heuristic algorithm to narrow this optimization strategy space,on the basis of this optimization strategy ,present a 2-way semi-join query optimization algorithm based on grid service, finaliy ,in the grid computing environment, make the contrast experiment of the algorithm and the general all connection al- gorithm,and it proves that 2-way semi-join query optimization algorithm based on grid services can greatly shorten query responding time.