摘要
查询优化是分布式数据库技术的核心问题,主要针对连接等一些具有较高执行代价的操作进行研究。本文首先阐明了查询优化的主要目的,接着介绍了1-PSJ算法和n-PSJ算法,然后在其基础上提出了一种新的改进算法—CR(CompressedandReliable)算法,该算法应用到地理信息数据库中并取得了较好的效果。
Distributed query optimization is an important aspect of the technology of the distributed database. We mainly research on some operations that have higher executing cost. In this paper, we first illuminate the primary objective of distributed query optimization, in succession introduce two algorithms about query optimization： 1-PSJ and n-PSJ. Then according to them, we put forward one new algorithm--CR （Compressed and Reliable）. It has better efficiency to apply this algorithm to the database for geography.
出处
《现代计算机》
2006年第4期34-37,共4页
Modern Computer
关键词
分布式数据库
执行代价
查询优化
Distributed Database
Executing Cost
Query Optimization
