mysql> explain SELECT t.priority,t.value,count(DISTINCT t.triggerid) AS cnt FROM triggers t WHERE t.triggerid BETWEEN '13040' AND '13045' OR t.triggerid BETWEEN '26416' AND '26421' OR t.triggerid BETWEEN '26659' AND '26664' OR t.triggerid BETWEEN '26692' AND '26697' GROUP BY t.priority,t.value;
+----+-------------+-------+-------+---------------+---------+---------+------+------+-----------------------------+
| id | select_type | table | type  | possible_keys | key     | key_len | ref  | rows | Extra                       |
+----+-------------+-------+-------+---------------+---------+---------+------+------+-----------------------------+
|  1 | SIMPLE      | t     | range | PRIMARY       | PRIMARY | 8       | NULL |    4 | Using where; Using filesort |
+----+-------------+-------+-------+---------------+---------+---------+------+------+-----------------------------+
1 row in set (0.01 sec)