摘要
分析了并行数据库查询算法Ｍｅｒｇｅ－Ｕｐｄａｔｅ的性能，提出一种新的流水线查询思想，并基于该思想对算法Ｍｅｒｇｅ－Ｕｐｄａｔｅ加以改进，给出Ｐｉｐｅｌｉｎｅ算法过程，对比分析两种算法的不同特点。归纳出Ｐｉｐｅｌｉｎｅ算法的形式化描述形式，采用典型数学公式对两种算法的性能值进行计算，比较二者的性能，突出Ｐｉｐｅｌｉｎｅ算法的优越性。
This paper analyses the algorithm Merge-Update of the Parallel Database, and presents a new strategy-Pipeline query.Then based on this strategy,the authors develop a Pipeline algorithm applied to the same environment as the Merge-Update's.and compare them with their special characters.At the end of this paper,the authors summarize the Pipeline's procedure description, and accumulate the performance of this two algorithm with the classic formula. Then this paper compares the two algorithms' performance to show the Pipeline's superiority and to lay a good foumdation for the advanced research work on the Parallel Database Query Optimization.
