SQLServer数据库管理系统上的SQL查询优化.docVIP

SQL Server 数据库管理系统上的SQL查询优化 摘要 人们在使用SQL时往往会陷入一个误区，即太关注于所得的结果是否正确，而忽略了不同的实现方法之间可能存在的性能差异，这种性能差异在大型的或是复杂的数据库环境中（如联机事务处理OLTP或决策支持系统DSS）中表现得尤为明显。不良的SQL往往来自于不恰当的索引设计、不充份的连接条件和不可优化的where子句。在对它们进行适当的优化后，其运行速度将有比较明显的提高。 为了最有效地优化 Microsoft SQL Server 的性能，您必须明确在哪些方面性能可以得到最大程度的改进，并集中分析这些方面。否则，您在这些问题上可能花费大量的时间和精力，而并不能得到明显的性能上的提高。 设计一个应用系统似乎并不难，但是要想使系统达到最优化的性能并不是一件容易的事。在开发工具、数据库设计、应用程序的结构、查询设计、接口选择等方面有多种选择，这取决于特定的应用需求以及开发队伍的技能。 关键词：SQL Server数据库 性能优化 查询 数据查询 查询效率 安全性 ABSTRACT People will often fall into a ill idea while using SQL, namely it is correct to pay close attention to the result to the income very much, and has neglected the performance difference that may exist between different implementation methods , this kind of performance difference behaves particularly obviously in the large-scale or complicated database environment (such as on-line transaction processing OLTP or DSS ). I find bad SQL come from appropriate index design , fill connection terms and where clause that cant be optimized of copy often among working practice. After carrying on proper optimization to them, its speed of operation improves obviously! In order to optimize the performance of Microsoft SQL Server most effectively, you must define in which respects performance can get maximum improvement , concentrate on analysing these respects. Otherwise, you are on these questions may spend a large amount of time and energy , but can not receive the improvement on obvious performance . It seems easy to design a application system, but it is not an easy thing to want to make the system reach the performance optimized most. Respect of choosing on developing instrument , database design , structure , inquiry design , interface of the application program etc. has excellent choices, this depends on specific application demand and develops the skill of the team . Keyword: SQL Server database Performance optimizing Inquiry Data inquiry Inquire about efficiency Security 目 录 摘 要----------------------