摘要
研究发现给定条件下的全局优化算法可用于具有非等连接的多连接查询中 ,并且与join操作产生的关系大小的估算模型无关 .对于星状查询 ,应用join产生关系的大小估算模型 ,证明全局优化算法所生成的join序列具有任意 3个相邻的join操作序列是最优的特性 .
On the basis of the given condition,it is shown that the global optimization algorithm can apply to equi_join or nonequi_join and has nothing to do with the estimation model of the join_later size in muti_join queries,and that for star queries, the algorithm can produce join sequences with the following global optimization property.In the join sequence, arbitrary subsequence formed by three neighboring joins is optimum.
出处
《中山大学学报（自然科学版）》
CAS
CSCD
北大核心
2001年第2期27-30,共4页
Acta Scientiarum Naturalium Universitatis Sunyatseni
