mysql快速生成测试数据的方法，以及分页limit语句优化

1、创建表：

person MyISAM

CREATE TABLE `person` (
`id` bigint(20) unsigned NOT NULL AUTO_INCREMENT,
`fname` varchar(255) NOT NULL,
`age` tinyint(3) unsigned NOT NULL,
`sex` tinyint(1) unsigned NOT NULL,
PRIMARY KEY (`id`)
) ENGINE=MyISAM DEFAULT CHARSET=utf8

person1 InnoDB

CREATE TABLE `person1` (
`id` bigint(20) unsigned NOT NULL AUTO_INCREMENT,
`fname` varchar(255) NOT NULL,
`age` tinyint(3) unsigned NOT NULL,
`sex` tinyint(1) unsigned NOT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8

2、创建存储过程：

CREATE  PROCEDURE `generate`(IN num INT)
BEGIN
DECLARE chars varchar(100) DEFAULT 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789';
DECLARE fname VARCHAR(25) DEFAULT '';
DECLARE lname VARCHAR(25) DEFAULT '';
DECLARE id int UNSIGNED;
DECLARE len int;
set id=1;
#DELETE from person;
WHILE id <= num DO
set len = FLOOR(1 + RAND()*25);
set fname = '';
WHILE len > 0 DO
SET fname = CONCAT(fname,substring(chars,FLOOR(1 + RAND()*62),1));
SET len = len - 1;
END WHILE;
INSERT into person VALUES (NULL,fname,FLOOR(RAND()*100), FLOOR(RAND()*2));
set id = id + 1;
END WHILE;
END

3、生成数据，可以不断添加不会清空原有数据：

generate(100000);

4、生成数据测试：

person:

第一次：

[SQL]CALL generate(100000);
受影响的行: 1
时间: 630.181s

第二次：连续两次10W

[SQL]CALL generate(100000);
受影响的行: 1
时间: 614.775s

[SQL]
CALL generate(100000);
受影响的行: 1
时间: 642.726s

第三次：300W

[SQL]CALL generate(3000000);
受影响的行: 1
时间: 3029.854s

person1: 300W

[SQL]call generate(3000000);
受影响的行: 1
时间: 3888.488s

5、查询测试：

测试代码：

SELECT * FROM person LIMIT 2800000,10;
SELECT * FROM person AS a INNER JOIN(SELECT id FROM person LIMIT 2800000,10) AS b ON a.id=b.id;

SELECT * FROM person AS a INNER JOIN(SELECT id FROM person LIMIT 2200000,10) AS b ON a.id=b.id;
SELECT * FROM person LIMIT 2200000,10;

SELECT * FROM person1 LIMIT 2800000,10;
SELECT * FROM person1 AS a INNER JOIN(SELECT id FROM person1 LIMIT 2800000,10) AS b ON a.id=b.id;

SELECT * FROM person1 AS a INNER JOIN(SELECT id FROM person1 LIMIT 2200000,10) AS b ON a.id=b.id;
SELECT * FROM person1 LIMIT 2200000,10;

测试结果：

[SQL]SELECT * FROM person LIMIT 2800000,10;
受影响的行: 0
时间: 1.175s

[SQL]
SELECT * FROM person AS a INNER JOIN(SELECT id FROM person LIMIT 2800000,10) AS b ON a.id=b.id;
受影响的行: 0
时间: 1.362s

[SQL]

SELECT * FROM person AS a INNER JOIN(SELECT id FROM person LIMIT 2200000,10) AS b ON a.id=b.id;
受影响的行: 0
时间: 1.046s

[SQL]
SELECT * FROM person LIMIT 2200000,10;
受影响的行: 0
时间: 0.891s

[SQL]

SELECT * FROM person1 LIMIT 2800000,10;
受影响的行: 0
时间: 2.230s

[SQL]
SELECT * FROM person1 AS a INNER JOIN(SELECT id FROM person1 LIMIT 2800000,10) AS b ON a.id=b.id;
受影响的行: 0
时间: 1.468s

[SQL]

SELECT * FROM person1 AS a INNER JOIN(SELECT id FROM person1 LIMIT 2200000,10) AS b ON a.id=b.id;
受影响的行: 0
时间: 1.183s

[SQL]
SELECT * FROM person1 LIMIT 2200000,10;
受影响的行: 0
时间: 1.738s

六、总结：

数据查找越往后的情况下：

MyISAM：关键字索引不起作用，不必优化；

InnoDB：有了关键字索引，快了30%；