A first taste of logs on demand

From time to time I install MySQL from the development tree, to see what's new, and in the latest one I found a pleasant surprise:

Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 3 to server version: 5.1.12-beta

Type 'help;' or '\h' for help. Type '\c' to clear the buffer.

mysql [localhost] {datacharmer} ((none)) > show variables like "%log";
+--------------------------------+-------+
| Variable_name                  | Value |
+--------------------------------+-------+
| back_log                       | 50    |
| general_log                    | OFF   |
| innodb_locks_unsafe_for_binlog | OFF   |
| log                            | OFF   |
| slow_query_log                 | OFF   |
| sync_binlog                    | 0     |
+--------------------------------+-------+
6 rows in set (0.00 sec)

mysql [localhost] {datacharmer} ((none)) > select * from mysql.general_log;
Empty set (0.01 sec)

mysql [localhost] {datacharmer} ((none)) > set global general_log=1;
Query OK, 0 rows affected (0.01 sec)

mysql [localhost] {datacharmer} ((none)) > select * from mysql.general_log;
+---------------------+-----------------------------------------+-----------+-----------+--------------+---------------------------------+
| event_time          | user_host                               | thread_id | server_id | command_type | argument                        |
+---------------------+-----------------------------------------+-----------+-----------+--------------+---------------------------------+
| 2006-07-05 17:26:56 | datacharmer[datacharmer] @ localhost [] |         3 |         0 | Query        | select * from mysql.general_log |
+---------------------+-----------------------------------------+-----------+-----------+--------------+---------------------------------+
1 row in set (0.04 sec)

mysql [localhost] {datacharmer} ((none)) > select * from mysql.general_log;
+---------------------+-----------------------------------------+-----------+-----------+--------------+---------------------------------+
| event_time          | user_host                               | thread_id | server_id | command_type | argument                        |
+---------------------+-----------------------------------------+-----------+-----------+--------------+---------------------------------+
| 2006-07-05 17:26:56 | datacharmer[datacharmer] @ localhost [] |         3 |         0 | Query        | select * from mysql.general_log |
| 2006-07-05 17:27:08 | datacharmer[datacharmer] @ localhost [] |         3 |         0 | Query        | select * from mysql.general_log |
+---------------------+-----------------------------------------+-----------+-----------+--------------+---------------------------------+
2 rows in set (0.00 sec)

mysql [localhost] {datacharmer} ((none)) > set global general_log=0;
Query OK, 0 rows affected (0.01 sec)

mysql [localhost] {datacharmer} ((none)) > select * from mysql.general_log;
+---------------------+-----------------------------------------+-----------+-----------+--------------+---------------------------------+
| event_time          | user_host                               | thread_id | server_id | command_type | argument                        |
+---------------------+-----------------------------------------+-----------+-----------+--------------+---------------------------------+
| 2006-07-05 17:26:56 | datacharmer[datacharmer] @ localhost [] |         3 |         0 | Query        | select * from mysql.general_log |
| 2006-07-05 17:27:08 | datacharmer[datacharmer] @ localhost [] |         3 |         0 | Query        | select * from mysql.general_log |
| 2006-07-05 17:27:11 | datacharmer[datacharmer] @ localhost [] |         3 |         0 | Query        | set global general_log=0        |
+---------------------+-----------------------------------------+-----------+-----------+--------------+---------------------------------+
3 rows in set (0.00 sec)

As you can see, the promised logs on demand are there.
This feature was long overdue. Well done!