一种改进的多关系半连接数据库查询算法

An Improved Database-query Algorithm for Multi-relation Semi Joins

提出了一个普通的多关系半连接操作查询优化算法,并在该算法基础上加以改进,结果表明:当Card(R)远远大于Card(R)时,改进算法减少了数据的传输量,减少了查询的总代价,从而操作效率大大的提高.

The query efficiency is too important a problem to be ignored in the database query management system. A new optimization algorithm for database query based on multi-relation semi joins is proposed, on basis of which improvement is further made. And the results show that the improved algorithm drastically reduces the amount of data transmission and the total query cost, and thus immensely enhance the operating efficiency.