【MySQL】CROSS JOINについて

次の２つのようなテーブルがあった時に全てのパターンを表示するコマンドらしい。
使い道不明。シンプルにすべてのパターンの総数を導き出したい時とか？

customers

mysql> SELECT
    ->  *
    -> FROM customers;

id	first_name	last_name	email
1	Boy	George	[e-mail]
2	George	Michael	[e-mail]
3	David	Bowie	[e-mail]
4	Blue	Steele	[e-mail]
5	Bette	Davis	[e-mail]

orders

mysql> SELECT
    ->  *
    -> FROM orders;

id	order_date	amount	customer_id
1	2016-02-10	99.99	1
2	2017-11-11	35.50	1
3	2014-12-12	800.67	2
4	2015-01-03	12.50	2
5	1999-04-11	450.25	5

CROSS JOIN結果

mysql> SELECT
    ->  *
    -> FROM customers
    -> CROSS JOIN orders;

id	first_name	last_name	email	id	order_date	amount	customer_id
5	Bette	Davis	[e-mail]	1	2016-02-10	99.99	1
4	Blue	Steele	[e-mail]	1	2016-02-10	99.99	1
3	David	Bowie	[e-mail]	1	2016-02-10	99.99	1
2	George	Michael	[e-mail]	1	2016-02-10	99.99	1
1	Boy	George	[e-mail]	1	2016-02-10	99.99	1
5	Bette	Davis	[e-mail]	2	2017-11-11	35.50	1
4	Blue	Steele	[e-mail]	2	2017-11-11	35.50	1
3	David	Bowie	[e-mail]	2	2017-11-11	35.50	1
2	George	Michael	[e-mail]	2	2017-11-11	35.50	1
1	Boy	George	[e-mail]	2	2017-11-11	35.50	1
5	Bette	Davis	[e-mail]	3	2014-12-12	800.67	2
4	Blue	Steele	[e-mail]	3	2014-12-12	800.67	2
3	David	Bowie	[e-mail]	3	2014-12-12	800.67	2
2	George	Michael	[e-mail]	3	2014-12-12	800.67	2
1	Boy	George	[e-mail]	3	2014-12-12	800.67	2
5	Bette	Davis	[e-mail]	4	2015-01-03	12.50	2
4	Blue	Steele	[e-mail]	4	2015-01-03	12.50	2
3	David	Bowie	[e-mail]	4	2015-01-03	12.50	2
2	George	Michael	[e-mail]	4	2015-01-03	12.50	2
1	Boy	George	[e-mail]	4	2015-01-03	12.50	2
5	Bette	Davis	[e-mail]	5	1999-04-11	450.25	5
4	Blue	Steele	[e-mail]	5	1999-04-11	450.25	5
3	David	Bowie	[e-mail]	5	1999-04-11	450.25	5
2	George	Michael	[e-mail]	5	1999-04-11	450.25	5
1	Boy	George	[e-mail]	5	1999-04-11	450.25	5