c++ - mysql中show status like和show variables like数据出处

Question

不太清楚show variables与show status的内在区别，我的猜测是：
1.show variables读出的内容来自编译时设置的选项、配置文件、mysql命令行下的动态设置；
2.show status读出的内容则是动态的，是mysql运行时的动态变化：(1)可能来自进程运行时内部动态改变的参数信息；(2)可能来自数据库表：例如information_schema，performance_schema，mysql

不知道我的看法是不是正确，希望高手赐教。先谢过。

Answer 1

关于show variables官方文档有提到一些：

System variable information is also available from these sources:
Performance Schema tables. See Section 21.9.12, “Performance Schema System Variable Tables”.
The GLOBAL_VARIABLES and SESSION_VARIABLES tables. See Section 20.10, “The INFORMATION_SCHEMA GLOBAL_VARIABLES and SESSION_VARIABLES Tables”.
The mysqladmin variables command. See Section 4.5.2, “mysqladmin — Client for Administering a MySQL Server”.

关于show status官方文档描述如下：

tatus variable information is also available from these sources:
Performance Schema tables. See Section 21.9.13, “Performance Schema Status Variable Tables”.
The GLOBAL_STATUS and SESSION_STATUS tables. See Section 20.9, “The INFORMATION_SCHEMA GLOBAL_STATUS and SESSION_STATUS Tables”.
The mysqladmin extended-status command. See Section 4.5.2, “mysqladmin — Client for Administering a MySQL Server”.

Answer 2

看文档很重要，这是mysql官方的说明，附两个链接。
http://dev.mysql.com/doc/refman/5.7/en/server-system-variables.html
https://dev.mysql.com/doc/refman/5.7/en/performance-schema-variable-table-migration.html