gistfile1.txt

mysql> explain SELECT pollip_aid FROM wp_pollsip WHERE pollip_qid = 158 AND pollip_ip = '157.56.92.155';
+----+-------------+------------+------+---------------+------+---------+------+--------+-------------+
| id | select_type | table      | type | possible_keys | key  | key_len | ref  | rows   | Extra       |
+----+-------------+------------+------+---------------+------+---------+------+--------+-------------+
|  1 | SIMPLE      | wp_pollsip | ALL  | pollip_qid    | NULL | NULL    | NULL | 914036 | Using where |
+----+-------------+------------+------+---------------+------+---------+------+--------+-------------+
1 row in set



KEY `pollip_qid_2` (`pollip_qid`, `pollip_ip`)

mysql> explain SELECT SQL_NO_CACHE pollip_aid FROM wp_pollsip USE INDEX (pollip_qid_2) WHERE pollip_qid = 158 AND pollip_ip = '157.56.92.155';
+----+-------------+------------+------+---------------+------+---------+------+--------+-------------+
| id | select_type | table      | type | possible_keys | key  | key_len | ref  | rows   | Extra       |
+----+-------------+------------+------+---------------+------+---------+------+--------+-------------+
|  1 | SIMPLE      | wp_pollsip | ALL  | pollip_qid_2  | NULL | NULL    | NULL | 914053 | Using where |
+----+-------------+------------+------+---------------+------+---------+------+--------+-------------+
1 row in set




KEY `pollip_qid_2` (`pollip_ip`,`pollip_qid`)

mysql> explain SELECT SQL_NO_CACHE pollip_aid FROM wp_pollsip USE INDEX (pollip_qid_2) WHERE pollip_qid = 158 AND pollip_ip = '157.56.92.155';
+----+-------------+------------+------+---------------+--------------+---------+-------+------+-------------+
| id | select_type | table      | type | possible_keys | key          | key_len | ref   | rows | Extra       |
+----+-------------+------------+------+---------------+--------------+---------+-------+------+-------------+
|  1 | SIMPLE      | wp_pollsip | ref  | pollip_qid_2  | pollip_qid_2 | 102     | const |    1 | Using where |
+----+-------------+------------+------+---------------+--------------+---------+-------+------+-------------+
1 row in set




mysql> explain SELECT SQL_NO_CACHE pollip_aid FROM wp_pollsip WHERE pollip_qid = 158 AND pollip_ip = '157.56.92.155';
+----+-------------+------------+------+-------------------------+--------------+---------+-------+------+-------------+
| id | select_type | table      | type | possible_keys           | key          | key_len | ref   | rows | Extra       |
+----+-------------+------------+------+-------------------------+--------------+---------+-------+------+-------------+
|  1 | SIMPLE      | wp_pollsip | ref  | pollip_qid,pollip_qid_2 | pollip_qid_2 | 102     | const |    1 | Using where |
+----+-------------+------------+------+-------------------------+--------------+---------+-------+------+-------------+
1 row in set