MySQL Variables debug 数据库 参数变量解释及正确配置使用
本站中文解释
MySQL参数变量debug用于启用MySQL的调试模式，它会在MySQL服务器的错误日志文件中写入有价值的调试信息。
要设置MySQL参数变量debug，首先要关闭MySQL服务器，然后打开MySQL的配置文件（my.cnf），搜索debug关键字，如果没有该参数名，则在[mysqld]节点下新增debug=1参数，如果debug参数名存在，将debug参数值修改为1.最后保存配置文件，启动MySQL服务器。
官方英文解释
debug
| Command-Line Format | --debug[=debug_options] |
|---|---|
| System Variable | debug |
| Scope | Global, Session |
| Dynamic | Yes |
| Type | String |
| Default Value (Unix) | d:t:i:o,/tmp/mysqld.trace |
| Default Value (Windows) | d:t:i:O,\mysqld.trace |
This variable indicates the current debugging settings. It is
available only for servers built with debugging support. The
initial value comes from the value of instances of the
--debug option given at server
startup. The global and session values may be set at runtime.
Setting the session value of this system variable is a
restricted operation. The session user must have privileges
sufficient to set restricted session variables. See
Section 5.1.8.1, “System Variable Privileges”.
Assigning a value that begins with + or
- cause the value to added to or subtracted
from the current value:
mysql>SET debug = 'T';mysql>SELECT @@debug;+---------+ | @@debug | +---------+ | T | +---------+ mysql>SET debug = '+P';mysql>SELECT @@debug;+---------+ | @@debug | +---------+ | P:T | +---------+ mysql>SET debug = '-P';mysql>SELECT @@debug;+---------+ | @@debug | +---------+ | T | +---------+
For more information, see Section 5.8.3, “The DBUG Package”.
