摘要
现有的较成熟的分布式数据库系统大都是不含水平划分的,而水平划分能够提高许多数据库操作的时空效率。本文介绍O^2D^2B中包含水平划分的分布式查询处理,主要包括与查询语句相关各表的分布地址集的获得、数据传输费用的计算与执行地点的选择,其中着重介绍通过对查询语句where子句条件表达式的分析,如何得到表的分布信息。与一般水平划分不同的是,O^2D^2B支持多属性划分,并且在划分中可以有重叠包含关系。因此,O^2D^2B具有更强的适用性。
In general, distributed database systems do not include horizontal partition. But the partition can raise the time - space efficiency for a variety of database operations. This paper introduces the horizontal partition and distributed query processing in O2D2B system, including getting die distributed address set of tables related to the query language, evaluating data transfer cost and selecting its executing site. The focus is on how to get the tables' distribution information by analysing the where substatement's condition expression in a query statement. Contrast to others, O2 D2 B system supports a multi-attribute partition and overlapping containning relation.Therefore,it has more powerful suitability.
出处
《计算机应用与软件》
CSCD
1998年第5期20-24,共5页
Computer Applications and Software
