数据库查询优化技术的研究与实现

Query Optimization Rearch of Database and Its Implementation

本文从查询重写和查询计划执行两方面对数据库查询优化方法进行研究,查询重写将查询语句转化为具有相同语义的语句,一般来讲转换后的语句执行效率较高或更有利于后面的处理,文中给出了一系列查询重写规则,在查询计划执行层面通过多线程和并行计算技术,提出了一套优化机制,最后通过TPC-H基准测试对查询优化前后的性能进行对比分析。

In this paper, we research on the query optimization techniques from two aspects of query rewriting and query plan execution, query rewriting converted the query to the same semantic statements, in general the converted statement execution efficiency is higher or more conducive to handle at the backend, the paper will give a series of query rewriting rules, at the level of query plan executing we present a set of optimization mechanism using multithreading and parallel computing techniques, and finally through the TPC-H benchmark to analyze the optimized database performance before and after.