This chapter explains how to optimize MySQL performance and provides examples. 本章介绍如何优化MySQL性能并提供示例。Optimization involves configuring, tuning, and measuring performance, at several levels. 优化包括在多个级别上配置、调优和度量性能。Depending on your job role (developer, DBA, or a combination of both), you might optimize at the level of individual SQL statements, entire applications, a single database server, or multiple networked database servers. 根据您的工作角色（开发人员、DBA或两者的组合），您可以在单个SQL语句、整个应用程序、单个数据库服务器或多个联网数据库服务器的级别上进行优化。Sometimes you can be proactive and plan in advance for performance, while other times you might troubleshoot a configuration or code issue after a problem occurs. 有时，您可以积极主动地提前计划性能，而有时，您可能会在出现问题后对配置或代码问题进行故障排除。Optimizing CPU and memory usage can also improve scalability, allowing the database to handle more load without slowing down.优化CPU和内存使用也可以提高可伸缩性，允许数据库在不降低速度的情况下处理更多负载。