【作者】 李大庆； 郑振楣； 石树刚；

【Author】 Li Daqing,Zheng zhenmei and Shi shugang Dept.of Computer Science,Wuhan University(430072)

【机构】 武汉大学计算机科学系；

【摘要】 用面向对象的方法模型化查询优化器,把随机化搜索策略与传统的搜索策略统一在一个优化器中,以满足不同应用领域的查询要求。本文探讨了这两类基本的搜索策略在DDBS中扩展的可能性,指出如果采用联接而不是半联接作为查询优化的基本策略,就可以在DDBS的查询优化器中实现搜索策略的扩展性,并对其算法给出具体扩展。更多还原

【Abstract】 In order to cope with efficiently different query types and application requirements,We have to integrate randomized search strategy with traditional search strategy in the Object-Oriented modeling of query optimizer.This paper discusses the possibility of the extension of two fundanmental search strategy in DDBS.It also concludes that if join operation instead of semi_join operation is used for basic strategy of query optimization,We can extend search strategy in query optimizer of DDBS.The paper also extends their algorithms in DDBS.更多还原