语法
SET variable = expr [, variable = expr] ... variable: { user_var_name | {GLOBAL | @@GLOBAL.} system_var_name | [SESSION | @@SESSION. | @@] system_var_name }
注意事项
使用SET GLOBAL设置全局变量时，PolarDB-X会将其进行持久化，实例重启后仍然生效。此外，SET GLOBAL设置成功后，所有已有的连接都会生效。
示例
mysql> SET @foo='bar'; Query OK, 0 rows affected (0.00 sec) mysql> SELECT @foo; +------+ | @foo | +------+ | bar | +------+ 1 row in set (0.01 sec) mysql> SET @@time_zone='+09:00'; Query OK, 0 rows affected (0.01 sec) mysql> SELECT @@time_zone; +-------------+ | @@time_zone | +-------------+ | +09:00 | +-------------+ 1 row in set (0.00 sec) mysql> SET GLOBAL time_zone='+09:00'; Query OK, 0 rows affected (0.04 sec) mysql> SELECT @@GLOBAL.time_zone; +--------------------+ | @@global.time_zone | +--------------------+ | +09:00 | +--------------------+ 1 row in set (0.02 sec)