企业海量数据查询优化

The Corporate Mass Data Query Optimizer

摘要: 在一个应用系统中，对数据查询及处理速度已成为衡量该系统成败的标准，所以在对大型数据库查询时，应注意数据查询的工作效率，以免造成系统资源严重浪费。本文根据以语法为基础的查询优化器的工作原理，合理建立索引，书写规范良好的SQL语句，使用合适的表达式或关键字，充分利用索引，避免全表扫描，提高查询效率。

Abstract: In an application system, data query and processing speed has become a standard to measure the success or failure of the system. Thus, in large database queries, you should pay attention to the efficiency of the data query, so as not to cause a serious waste of system resources. Based on the grammar-based query optimizer works, this paper reasonably establishes indexing, writes good specifications SQL statement, uses appropriate expressions or keywords, makes full use of the index, avoids full table scan and improves query efficiency.