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percona-toolkit/t/pt-visual-explain/samples/index_subquery_in_where_clause.sql
2011-06-24 16:02:05 -06:00

11 lines
960 B
SQL

mysql> explain select count(*) from sakila.actor where actor_id in (select actor_id from sakila.film_actor);
+----+--------------------+------------+----------------+---------------+---------+---------+------+------+--------------------------+
| id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra |
+----+--------------------+------------+----------------+---------------+---------+---------+------+------+--------------------------+
| 1 | PRIMARY | actor | index | NULL | PRIMARY | 2 | NULL | 200 | Using where; Using index |
| 2 | DEPENDENT SUBQUERY | film_actor | index_subquery | PRIMARY | PRIMARY | 2 | func | 13 | Using index |
+----+--------------------+------------+----------------+---------------+---------+---------+------+------+--------------------------+
2 rows in set (0.00 sec)
mysql> notee