MySQL生成千万测试数据以及遇到的问题

CREATE TABLE `t_user` (
 `id` int(11) NOT NULL AUTO_INCREMENT,
 `c_user_id` varchar(36) NOT NULL DEFAULT '',
 `c_name` varchar(22) NOT NULL DEFAULT '',
 `c_province_id` int(11) NOT NULL,
 `c_city_id` int(11) NOT NULL,
 `create_time` datetime NOT NULL,
 PRIMARY KEY (`id`),
 KEY `idx_user_id` (`c_user_id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;

CREATE TABLE `t_user_memory` (
 `id` int(11) NOT NULL AUTO_INCREMENT,
 `c_user_id` varchar(36) NOT NULL DEFAULT '',
 `c_name` varchar(22) NOT NULL DEFAULT '',
 `c_province_id` int(11) NOT NULL,
 `c_city_id` int(11) NOT NULL,
 `create_time` datetime NOT NULL,
 PRIMARY KEY (`id`),
 KEY `idx_user_id` (`c_user_id`)
) ENGINE=MEMORY DEFAULT CHARSET=utf8mb4;

# 创建随机字符串
delimiter $$
CREATE DEFINER = `root` @`%` FUNCTION `randStr` ( n INT ) RETURNS VARCHAR ( 255 ) CHARSET utf8mb4 DETERMINISTIC 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 $$ 
# 创建随机时间的函数，sd和ed两个入参代表生成的时间是这个时间范围内的。sd开始时间，ed截止时间。	
CREATE DEFINER = `root` @`%` FUNCTION `randDataTime` ( sd DATETIME, ed DATETIME ) RETURNS datetime DETERMINISTIC BEGIN
	DECLARE
		sub INT DEFAULT 0;
	DECLARE
		ret DATETIME;
	
	SET sub = ABS(
	UNIX_TIMESTAMP( ed )- UNIX_TIMESTAMP( sd ));
	
	SET ret = DATE_ADD( sd, INTERVAL FLOOR( 1+RAND ()*( sub - 1 )) SECOND );
	RETURN ret;

END $$ 

# 创建插入数据存储过程
CREATE DEFINER = `root` @`%` PROCEDURE `add_t_user_memory` ( IN n INT ) BEGIN
	DECLARE
		i INT DEFAULT 1;
	WHILE
			( i <= n ) DO
			INSERT INTO t_user_memory ( c_user_id, c_name, c_province_id, c_city_id, create_time )
		VALUES
			(
				uuid(),
				randStr ( 20 ),
				FLOOR( RAND() * 1000 ),
				FLOOR( RAND() * 100 ),
				randDataTime ( "2020-01-01", "2021-01-01" ));
		

		SET i = i + 1;
		
	END WHILE;

END $$
delimiter ;

CALL add_t_user_memory(10);

grant all privileges on *.* to 'root'@'%' identified by ".";
flush privileges;

show VARIABLES like '%TABLE_size%';

INSERT INTO t_user SELECT * FROM t_user_memory;