question about long_query_time

MySQL & MariaDB Other MySQL® Questions
1

I have set my db serser’s long_query_time to 0,but it seems it doesn’t seem work!

mysql> show global variables like ‘%long%’;
±----------------±---------+
| Variable_name | Value |
±----------------±---------+
| long_query_time | 0.000000 |
±----------------±---------+
1 row in set (0.00 sec)

The initial value is 5s,but after change to 0,it log some queries,but not all!

Can anybody tell me why？

2

There are old sessions that remain open and have not yet been affected by the change to the global variable. Percona’s patches have a method to force this to take effect:

http://www.percona.com/docs/wiki/patches:use_global_long_que ry_time

3

:o Thank you very much