gistfile1.txt

mysql> explain extended select * from t100 where col1 < 5 order by key1 limit 10;
+------+-------------+-------+-------+---------------+------+---------+------+------+----------+-------------+
| id   | select_type | table | type  | possible_keys | key  | key_len | ref  | rows | filtered | Extra       |
+------+-------------+-------+-------+---------------+------+---------+------+------+----------+-------------+
|    1 | SIMPLE      | t100  | index | NULL          | key1 | 5       | NULL |   10 |     0.99 | Using where |
+------+-------------+-------+-------+---------------+------+---------+------+------+----------+-------------+
1 row in set, 1 warning (0.00 sec)

mysql> explain extended select * from t100 where col1 > 5 order by key1 limit 10;
+------+-------------+-------+-------+---------------+------+---------+------+------+----------+-------------+
| id   | select_type | table | type  | possible_keys | key  | key_len | ref  | rows | filtered | Extra       |
+------+-------------+-------+-------+---------------+------+---------+------+------+----------+-------------+
|    1 | SIMPLE      | t100  | index | NULL          | key1 | 5       | NULL |   10 |    99.01 | Using where |
+------+-------------+-------+-------+---------------+------+---------+------+------+----------+-------------+
1 row in set, 1 warning (0.00 sec)