Extension:CentralAuth/global user groups table

mysql> describe global_user_groups;
+-----------+----------------+------+-----+---------+-------+
| Field     | Type           | Null | Key | Default | Extra |
+-----------+----------------+------+-----+---------+-------+
| gug_user  | int(11)        | NO   | PRI | NULL    |       |
| gug_group | varbinary(255) | NO   | PRI | NULL    |       |
+-----------+----------------+------+-----+---------+-------+