运用数据库优化器提高SQL查询效率

Improve SQL Query Efficiency with Database Optimizer

数据库优化器为数据库查询提供一个最佳的执行策略。执行策略是执行查询所需要的一系列步骤,数据库操作的反应速度经常就体现在这个优化算法上。不同的查询策略会使服务器的响应速度大相径庭。对数据库优化器的性能进行分析,给出四种查询优化策略。

The database optimizer provides an optimal executive strategy for database query. Theexecutive strategy is a series of steps execting query,the reaction speed of database operating is oftenreflected in the optimization algorithm. Different query strategies make much differencd in terms of theresponse rate of server. In this paper,first the property of database optimizer is analysed,then four queryoptimization strategies are given.