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1MySQL not using index for BETWEEN query. What am I doing wrong?
2MariaDB [alienvault]> explain extended SELECT * FROM alienvault_siem.acid_event WHERE (timestamp BETWEEN '2012-10-09 11:20:17' AND '2012-10-10 03:20:17');
3+------+-------------+------------+------+---------------+------+---------+------+---------+----------+-------------+
4| id   | select_type | table      | type | possible_keys | key  | key_len | ref  | rows    | filtered | Extra       |
5+------+-------------+------------+------+---------------+------+---------+------+---------+----------+-------------+
6|    1 | SIMPLE      | acid_event | ALL  | timestamp     | NULL | NULL    | NULL | 4481579 |    50.00 | Using where |
7+------+-------------+------------+------+---------------+------+---------+------+---------+----------+-------------+
81 row in set, 1 warning (0.01 sec)
9	
10CREATE TABLE IF NOT EXISTS `acid_event` (
11  (...)
12  `timestamp` datetime NOT NULL,
13  (...)
14  PRIMARY KEY (`id`),
15  (...)
16  KEY `timestamp` (`timestamp`),
17  (...)
18) ENGINE=InnoDB DEFAULT CHARSET=utf8;
19	
20WHERE timestamp 
21  BETWEEN str_to_date('2012-10-09 11:20:17','%Y-%m-%d %H:%i:%s') 
22      AND str_to_date('2012-10-10 03:20:17','%Y-%m-%d %H:%i:%s')