Increasing group_concat_max_len param in MySQL

SET GLOBAL group_concat_max_len=1024M

vi /etc/my.cnf

group_concat_max_len = 1024M

/etc/init.d/mysql restart

Shutting down MySQL......                                  [  OK  ]
Starting MySQL..                                           [  OK  ]

mysql -u root -p

Enter password:

mysql>SHOW VARIABLES LIKE "%group_concat_max_len";
+----------------------+------------+
| Variable_name        | Value      |
+----------------------+------------+
| group_concat_max_len | 1073741824 |
+----------------------+------------+
1 row in set (0.00 sec)