MySQL数据库在线修改slowlog

1, see the slow log status;mysql> show variables like %slow%;
+---------------------+------------------------------------------+
| Variable_name | Value |
+---------------------+------------------------------------------+
| log_slow_queries | ON |
| slow_launch_time | 2 |
| slow_query_log | ON |
| slow_query_log_file | /mysqllog/slow_log/slow_queries_3306.log |
+---------------------+------------------------------------------+
4 rows in set (0.00 sec)2, stop the slow log server.mysql> show variables like %slow%;mysql> set global slow_query_log=0;
Query OK, 0 rows affected (0.27 sec)+---------------------+------------------------------------------+
| Variable_name | Value |
+---------------------+------------------------------------------+
| log_slow_queries | OFF |
| slow_launch_time | 2 |
| slow_query_log | OFF |
| slow_query_log_file | /mysqllog/slow_log/slow_queries_3306.log |
+---------------------+------------------------------------------+
4 rows in set (0.00 sec)mysql>
mysql> show variables like %slow%; -- check slow log status
+---------------------+------------------------------------------+
| Variable_name | Value |
+---------------------+------------------------------------------+
| log_slow_queries | OFF |
| slow_launch_time | 2 |
| slow_query_log | OFF |
| slow_query_log_file | /mysqllog/slow_log/slow_queries_3306.log |
+---------------------+------------------------------------------+
4 rows in set (0.00 sec)3, reset the new path of slow logmysql> set global slow_query_log_file=/mysqllog/slow_log/slow_queries_3306_new.log;
Query OK, 0 rows affected (0.03 sec)mysql> 4, start the slow log servermysql>
mysql> set global slow_query_log=1;
Query OK, 0 rows affected (0.01 sec)
mysql> show variables like %slow%;
+---------------------+----------------------------------------------+
| Variable_name | Value |
+---------------------+----------------------------------------------+
| log_slow_queries | ON |
| slow_launch_time | 2 |
| slow_query_log | ON |
| slow_query_log_file | /mysqllog/slow_log/slow_queries_3306_new.log |
+---------------------+----------------------------------------------+
4 rows in set (0.00 sec)5, check the slow sql in the new slow log file.mysql> select sleep(10) as a, 1 as b;
+---+---+
| a | b |
+---+---+
| 0 | 1 |
+---+---+
1 row in set (10.00 sec)

引自：http://www.zhujiangroad.com/program/MySQL/71912.html