达梦数据库性能优化

本书以达梦数据库DM8 为蓝本，围绕DM8 性能为什么优化、谁来优化、优化什么、何时优化、优化到什么程度等问题进行详细介绍，从DM8 体系架构入手，分析了DM8 的运行机制，从DM8 的实例优化、I/O 优化、SQL 语句优化3 个方面详细地介绍了影响DM8 性能的核心问题。全书共6 章，内容包括DM8 性能优化概述、DM8体系架构、DM8 调优诊断工具、DM8 实例优化、DM8 I/O 优化和DM8 SQL 语句优化等。同时，本书还将DM8 参数配置文件相关参数、DM8 系统数据字典和DM8 常用动态性能视图作为附录，便于广大读者查阅。本书内容实用、示例丰富、语言通俗、格式规范，可以作为计算机、数据库等专业的教材，也可以作为工程技术人员的参考用书。

曾昭文，教授，主要从事数据工程和知识管理相关研究，主持军队重大科研项目10余项，先后获军队科技进步二等奖1项、三等奖多项，获军队教学成果二等奖1项，出版专著4部。

第1 章DM8 性能优化概述··············································································1

1.1 优化的基本概念·················································································1

1.1.1 为什么优化···············································································1

1.1.2 谁来优化··················································································2

1.1.3 优化什么··················································································2

1.1.4 何时优化··················································································4

1.1.5 优化到什么程度·········································································6

1.2 优化的基本思路·················································································7

1.2.1 数据库全面健康检查···································································7

1.2.2 优化阶段设计············································································7

1.2.3 数据库配置···············································································8

1.2.4 添加新的应用程序······································································8

1.2.5 运行过程的优化·········································································8

1.2.6 生产环境中优化的特殊问题··························································9

1.3 优化的基本步骤··············································································.10

1.3.1 问题分析···············································································.10

1.3.2 监控系统性能·········································································.11

1.3.3 数据库重演（REPLAY） ··························································.11

1.3.4 检查数据物理一致性································································.12

1.3.5 优化数据库布局······································································.12

1.4 数据库优化误区··············································································.13

第2 章 DM8 体系架构·················································································.14

2.1 总体构成·······················································································.14

2.1.1 数据库··················································································.15

2.1.2 实例·····················································································.15

2.2 物理存储结构·················································································.15

2.2.1 配置文件···············································································.16

2.2.2 控制文件···············································································.16

2.2.3 数据文件···············································································.17

2.2.4 日志文件················································································18

2.2.5 备份文件················································································21

2.2.6 数据重演文件··········································································21

2.3 逻辑存储结构···················································································21

2.3.1 表空间···················································································21

2.3.2 段·························································································24

2.3.3 簇·························································································25

2.3.4 页·························································································26

2.3.5 记录······················································································27

2.4 DM8 内存结构··················································································27

2.4.1 内存池···················································································27

2.4.2 缓冲区···················································································28

2.4.3 排序区···················································································30

2.4.4 哈希区···················································································31

2.5 DM8 线程结构··················································································31

2.5.1 监听线程·······················2