查询表达式优化的研究与实现  

ON QUERYING-EXPRESSION OPTIMIZATION AND ITS IMPLEMENTATION

作　　者：金洪伟[1] 苏厚勤[1] 

机构地区：[1]东华大学计算机科学与技术学院,上海200051

出　　处：《计算机应用与软件》2008年第6期123-125,共3页Computer Applications and Software

摘　　要：查询是数据库应用系统中使用最频繁的操作,其执行效率很大程度上影响了整个系统的性能。介绍了查询表达式优化的一般过程,在查询重写阶段提出了一种面向对象的框架,设计和实现了"多字段间关系自动推理"等若干种优化算法。测试结果表明,查询取得了良好的优化效果。Inquiries are most frequently used in database application system, the operation efficiency of them will greatly affect the performance of the whole system. This paper introduces general procedure of querying optimization, an object-riented frame in query-ewrite phase is proposed, and several optimized algorithms which include ＂uto-atiocination for Relationship among Multi-ields＂ have been planned and implemented. The testing results show that the query performance is well optimized.

关 键 词：查询表达式优化 WHERE子句 查询重写 

分 类 号：TP311.13[自动化与计算机技术—计算机软件与理论] O242.23[自动化与计算机技术—计算机科学与技术]