摘要
在一个企业级信息系统中,数据库端的性能对整个系统的有效运行起着关键的作用,而在数据库的性能上,数据查询的效率占据着十分重要的地位。文中根据Oracle9i中的数据查询机制以及优化器的特性,探讨了Oracle9i中数据库查询语句的优化,并着重对Oracle9i中的几种表连接技术进行了分析比较,给出了在实际开发中如何编写高效率的SQL查询语句。通过文中的分析结果,实现了应用系统在面临大量的数据时,能够快速对数据进行查询,保障系统的可靠运行。
In an enterprise -class information system, the performance of the database affects the whole system greatly, and on the database side the efficiency of data query affects its performance greatly. According to the mechanism of data query and the trait of the optimizer in Oraclegi, this paper introduces the optimization of data query in Oracle9i, analyzes and compares the different kinds of table connection in Oracle9i emphatically, and presnts how to write efficient SQL query statement in the software development. Based on the result of the analysis from this paper, it enables the rapid querying of the data and the steady running of the system when the application system is confronted with a great deal of data.
出处
《计算机技术与发展》
2006年第4期93-95,98,共4页
Computer Technology and Development
关键词
优化
优化器
查询优化
性能
表连接
optimization
optimizer
query optimization
performance
table connection
