explain
select actor_id,
(select count(film_id) from sakila.film join sakila.film_actor using(film_id))
from sakila.actor;
+----+-------------+------------+-------+----------------+--------------------+---------+---------------------+------+-------------+
| id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra |
+----+-------------+------------+-------+----------------+--------------------+---------+---------------------+------+-------------+
| 1 | PRIMARY | actor | index | NULL | PRIMARY | 2 | NULL | 200 | Using index |
| 2 | SUBQUERY | film | index | PRIMARY | idx_fk_language_id | 1 | NULL | 951 | Using index |
| 2 | SUBQUERY | film_actor | ref | idx_fk_film_id | idx_fk_film_id | 2 | sakila.film.film_id | 2 | Using index |
+----+-------------+------------+-------+----------------+--------------------+---------+---------------------+------+-------------+
3 rows in set (0.00 sec)
mysql> notee
|