mysql - 不使用索引的带有like和group的mysql查询

Question

我有一个查询没有使用正确的索引或根本没有任何索引的问题。

这是我的表创建

CREATE TABLE `data` (
 `data_id` int(10) unsigned NOT NULL AUTO_INCREMENT,
 `other_id` int(10) unsigned NOT NULL,
 `author_text` varchar(255) DEFAULT NULL,
 `sometext` text NOT NULL,
 `somehash` char(32) CHARACTER SET latin1 COLLATE latin1_general_ci NOT NULL,
 `longurl` varchar(255) NOT NULL,
 `published` int(11) NOT NULL,
 `language` varchar(3) DEFAULT NULL,
 `level` enum('-1','0','1','2') CHARACTER SET latin1 COLLATE latin1_general_ci NOT NULL DEFAULT '2',
 `day` int(11) NOT NULL,
 `processed` tinyint(4) NOT NULL DEFAULT '0',
 PRIMARY KEY (`data_id`),
 UNIQUE KEY `unique_url` (`other_id`,`somehash`),
 KEY `processed` (`processed`),
 KEY `language` (`day`,`language`)
) ENGINE=MyISAM AUTO_INCREMENT=2576573 DEFAULT CHARSET=utf8

查询

SELECT COUNT( * ) AS `num` , `data`.`language` AS `language`
FROM `data`
WHERE `data`.`author_text` LIKE '%test%'
AND `data`.`day`
BETWEEN '1364342400'
AND '1372118399'
GROUP BY `data`.`language`
ORDER BY `data`.`language` ASC 

解释

id|select_type|table|type|possible_keys|key |key_len|ref |rows   |Extra
--|-----------|-----|----|-------------|----|-------|----|-------|--------------------------------------------
1 |SIMPLE     |data |ALL |language     |NULL|NULL   |NULL|2563731|Using where; Using temporary; Using filesort