摘要
本文讨论了分布式查询处理中所涉及的主要概念和方法.文中给出了能用半连接运算完全简化出现在查询限制条件中的关系的查询特征.文中将基于半连接运算的查询处理算法分成三个阶段:副本标识阶段、简化阶段和综合阶段.我们讨论了树查询和循环查询的特征、树查询的识别和循环查询到树查询的转换.此外,本文还对简单查询和树查询的最佳策略以及半连接的启发式算法进行了讨论.
This paper discusses the primary concepts and methods related to distributed query processing. The paper also shows the characteristics of query using semi-join to fully reduce relations occurring in the query qualification and brings out a method of cost measurement Query processing algorithm based on semi-join is divided into three phases: copy identification phase, reduction phase and assembly phase. We also raise the characteristics of tree query and cyclic query, tree query recognition algorithm and transformation algorithm from cyclic query to tree query. Moreover, the paper approaches the optimal strategies of simple query and tree query, as well as heuristics algorithms based on semijoins.
出处
《计算机研究与发展》
EI
CSCD
北大核心
1989年第1期36-43,59,共9页
Journal of Computer Research and Development
