How to generate 1000000 rows with random data?

Question

Background

Im working on some kind of data logger.

I want to try how much storage space I need for 1000000 (1M) rows and how Raspberry Pi deals with such big table. I want to run some queries with grouping, calculating averages and other performance experiments.

My table looks like this:

CREATE TABLE `data` 
(
  `id`         bigint(20) NOT NULL      AUTO_INCREMENT,
  `datetime`   timestamp  NULL          DEFAULT CURRENT_TIMESTAMP,
  `channel`    int(11)                  DEFAULT NULL,
  `value`      float                    DEFAULT NULL,

  PRIMARY KEY (`id`)
)

Question

How can I fill it with 1000000 million rows in MySQL?

Requirements:

• data.datetime field: random timestamps but only from one year
• data.value field: random float numbers from given range (0.00-100.00 for example)
• data.id is autoincrement, no need to care about that
• data.channel is always 1, no need to care about that too

I know SQL a bit, but I'm not good in PL/SQL, loops in SQL etc.

EDIT:

To make it clear - im using MySQL 5.5.

Mentioned PL/SQL was my mistake, I thought PL/ stands for procedural features in SQL in general, not just Oracle.

Answer 1

Try it with a stored procedure (replace 1000 with desired amount of rows, and 2014 with test year, also see generate random timestamps in mysql)

CREATE TABLE `data` 
(
  `id`         bigint(20) NOT NULL      AUTO_INCREMENT,
  `datetime`   timestamp  NULL          DEFAULT CURRENT_TIMESTAMP,
  `channel`    int(11)                  DEFAULT NULL,
  `value`      float                    DEFAULT NULL,

  PRIMARY KEY (`id`)
);


DELIMITER $$
CREATE PROCEDURE generate_data()
BEGIN
  DECLARE i INT DEFAULT 0;
  WHILE i < 1000 DO
    INSERT INTO `data` (`datetime`,`value`,`channel`) VALUES (
      FROM_UNIXTIME(UNIX_TIMESTAMP('2014-01-01 01:00:00')+FLOOR(RAND()*31536000)),
      ROUND(RAND()*100,2),
      1
    );
    SET i = i + 1;
  END WHILE;
END$$
DELIMITER ;

CALL generate_data();

Modify to your needs. To delete the procedure:

DROP PROCEDURE generate_data;

Maybe this can give you a start!