optimize query for index using between and group by

[Raghavendra raghu]

CREATE TABLE ad_history (
ad_history_id bigint(20) unsigned NOT NULL AUTO_INCREMENT,
tpc_checkmaster varchar(40) DEFAULT NULL,
tpc_checkdate int(10) unsigned NOT NULL DEFAULT '0',
tpc_checkmasteraction
PRIMARY KEY (ad_history_id),
KEY INDEX_TPC_MASTER_ACTION_TIME (tpc_checkdate),
KEY idx_tpc_checkmaster_action (tpc_checkmaster,tpc_checkmasteraction),
) ENGINE=MyISAM AUTO_INCREMENT=12582

SELECT
tpc_checkmaster ,
tpc_checkmasteraction,
COUNT(*) AS adcount,
AVG(tpc_clearingtime) AS clearingtime
FROM
ad_history
WHERE
tpc_checkdate BETWEEN 1408437444 AND 1408519225
GROUP BY tpc_checkmaster , tpc_checkmasteraction
ORDER BY tpc_checkmaster , tpc_checkmasteraction


explain plan:
*************************** 1. row ***************************
id: 1
select_type: SIMPLE
table: admin_action_ad_history
type: range
possible_keys: INDEX_TPC_MASTER_ACTION_TIME,idx_tpc_checkmaster_action
key: INDEX_TPC_MASTER_ACTION_TIME
key_len: 4
ref: NULL
rows: 85
Extra: Using index condition; Using temporary; Using filesort
1 row in set (0.01 sec)


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