先模拟数据：
DROP DATABASE IF EXISTS oldboy;
CREATE TABLE t_100w (id INT,num INT,k1 CHAR(2),k2 CHAR(4),dt TIMESTAMP);
DELIMITER //
CREATE PROCEDURE rand_data(IN num INT)
BEGIN
DECLARE str CHAR(62) DEFAULT 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789';
DECLARE str2 CHAR(2);
DECLARE str4 CHAR(4);
DECLARE i INT DEFAULT 0;
WHILE i<num DO
SET str2=CONCAT(SUBSTRING(str,1+FLOOR(RAND()*61),1),SUBSTRING(str,1+FLOOR(RAND()*61),1));
SET str4=CONCAT(SUBSTRING(str,1+FLOOR(RAND()*61),2),SUBSTRING(str,1+FLOOR(RAND()*61),2));
SET i=i+1;
INSERT INTO t_100w VALUES (i,FLOOR(RAND()*num),str2,str4,NOW());
END WHILE;
END;
//
DELIMITER ;
CALL rand_data(1000000);
COMMIT;
#查询数据是否正确
select count(*) from t_100w;
下一步在linux下执行如下压力测试语句：
[root@Manager ~]# mysqlslap --defaults-file=/etc/my.cnf --concurrency=100 --iterations=1 --create-schema='oldboy' --query="select * from oldboy.t_100w where k2='CD23'" ENGINE=INNODB --number-of-queries=2000 -uroot -p123 -verbose
mysqlslap: [Warning] Using a password on the command line interface can be insecure.
Benchmark
Running for engine rbose
Average number of seconds to run all queries: 324.570 seconds
Minimum number of seconds to run all queries: 324.570 seconds
Maximum number of seconds to run all queries: 324.570 seconds
Number of clients running queries: 100
Average number of queries per client: 20
可以看到当前没有创建任何索引的情况下查询2000次的时间为324.570 seconds；
原因没有创建索引：
USE oldboy
DESC SELECT * FROM oldboy.t_100w WHERE k2='CD23'
id select_type table partitions type possible_keys key key_len ref rows filtered Extra
1 SIMPLE t_100w \N all null null 17 const 292 100.00 \N
SHOW INDEX FROM t_100w
ALTER TABLE t_100w ADD INDEX idx(k2);
DESC SELECT * FROM oldboy.t_100w WHERE k2='CD23'
id select_type table partitions type possible_keys key key_len ref rows filtered Extra
1 SIMPLE t_100w \N ref idx idx 17 const 292 100.00 \N
现在将查询语句进行优化，添加索引后重新执行命令后结果如下：
[root@Manager ~]# mysqlslap --defaults-file=/etc/my.cnf --concurrency=100 --iterations=1 --create-schema='oldboy' --query="select * from oldboy.t_100w where k2='CD23'" ENGINE=INNODB --number-of-queries=2000 -uroot -p123 -verbose
mysqlslap: [Warning] Using a password on the command line interface can be insecure.
Benchmark
Running for engine rbose
Average number of seconds to run all queries: 2.219 seconds
Minimum number of seconds to run all queries: 2.219 seconds
Maximum number of seconds to run all queries: 2.219 seconds
Number of clients running queries: 100
Average number of queries per client: 20
我们发现时间由300多秒缩减到只有2s左右 ，优化明显！
