mysql> EXPLAIN SELECT SQL_NO_CACHE *  FROM  al, a  WHERE a.a_id=al.a_id AND  g_id IN (6) ORDER BY l_name ASC  limit 1200 , 30;
+----+-------------+-------+--------+---------------+---------+---------+-------------------+------+-------------+
| id | select_type | table | type   | possible_keys | key     | key_len | ref               | rows | Extra       |
+----+-------------+-------+--------+---------------+---------+---------+-------------------+------+-------------+
|  1 | SIMPLE      | al    | index  | a_id          | l_name  | 770     | NULL              | 1230 |             |
|  1 | SIMPLE      | a     | eq_ref | PRIMARY       | PRIMARY | 4       | *********.al.a_id |    1 | Using where |
+----+-------------+-------+--------+---------------+---------+---------+-------------------+------+-------------+
2 rows in set (0.00 sec)