MySQL百万级数据大分页查询优化的实现

select * from product limit start, count

select * from product limit 10, 20       0.002秒
select * from product limit 1000, 20      0.011秒
select * from product limit 10000, 20     0.027秒
select * from product limit 100000, 20    0.057秒

select * from product limit 1000000, 20   0.682秒

select * from product limit 3000000, 20 1.368秒

select id from product limit 1000000, 20 0.2秒

select * from vote_record where id>=(select id from vote_record limit 1000000,1) limit 20;

select * from user where id>1000000 limit 100

//内存表
CREATE TABLE `vote_record_memory` (
	`id` INT (11) NOT NULL AUTO_INCREMENT,
	`user_id` VARCHAR (20) NOT NULL,
	`vote_id` INT (11) NOT NULL,
	`group_id` INT (11) NOT NULL,
	`create_time` datetime NOT NULL,
	PRIMARY KEY (`id`),
	KEY `index_id` (`user_id`) 
) ENGINE = MEMORY AUTO_INCREMENT = 1 DEFAULT CHARSET = utf8
 
//普通表
CREATE TABLE `vote_record` (
	`id` INT (11) NOT NULL AUTO_INCREMENT,
	`user_id` VARCHAR (20) NOT NULL,
	`vote_id` INT (11) NOT NULL,
	`group_id` INT (11) NOT NULL,
	`create_time` datetime NOT NULL,
	PRIMARY KEY (`id`),
	KEY `index_user_id` (`user_id`) 
) ENGINE = INNODB AUTO_INCREMENT = 1 DEFAULT CHARSET = utf8

//创建函数
CREATE FUNCTION `rand_string`(n INT) RETURNS varchar(255) CHARSET latin1
BEGIN 
DECLARE chars_str varchar(100) DEFAULT 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789'; 
DECLARE return_str varchar(255) DEFAULT '' ;
DECLARE i INT DEFAULT 0; 
WHILE i < n DO 
SET return_str = concat(return_str,substring(chars_str , FLOOR(1 + RAND()*62 ),1)); 
SET i = i +1; 
END WHILE; 
RETURN return_str; 
END

#创建插入内存表数据存储过程，入参n是多少就插入多少条数据
CREATE  PROCEDURE `add_vote_memory`(IN n int)
BEGIN
 DECLARE i INT DEFAULT 1;
 WHILE (i <= n) DO
   INSERT into vote_record_memory  (user_id,vote_id,group_id,create_time ) VALUEs (rand_string(20),FLOOR(RAND() * 1000),FLOOR(RAND() * 100) ,now() );
	 set i=i+1;
 END WHILE;
 END

#循环从内存表获取数据插入普通表
#参数描述 n表示循环调用几次；count表示每次插入内存表和普通表的数据量
 CREATE PROCEDURE `add_vote_memory_to_common`(IN n int, IN count int)
 BEGIN
 DECLARE i INT DEFAULT 1;
 WHILE (i <= n) DO
  CALL add_vote_memory(count);
	INSERT INTO vote_record SELECT * FROM vote_record_memory;
	delete from vote_record_memory;
	SET i = i + 1;
 END WHILE;
 END 

#循环调用100次，每次插入1W条数据
add_vote_memory_to_vote(100,10000);