MariaDB [tpch]> source Q4.sql;
+------+--------------------+----------+------+-------------------------------------+---------+---------+------------------------+---------+------------+----------+------------+----------------------------------------------+
| id   | select_type        | table    | type | possible_keys                       | key     | key_len | ref                    | rows    | r_rows     | filtered | r_filtered | Extra                                        |
+------+--------------------+----------+------+-------------------------------------+---------+---------+------------------------+---------+------------+----------+------------+----------------------------------------------+
|    1 | PRIMARY            | ORDERS   | ALL  | NULL                                | NULL    | NULL    | NULL                   | 1488318 | 1500000.00 |   100.00 |       3.46 | Using where; Using temporary; Using filesort |
|    2 | DEPENDENT SUBQUERY | LINEITEM | ref  | PRIMARY,IDX_LINEITEM_ORDERKEY_FKIDX | PRIMARY | 8       | tpch.ORDERS.O_ORDERKEY | 3       | 1.46       |   100.00 |      62.70 | Using where                                  |
+------+--------------------+----------+------+-------------------------------------+---------+---------+------------------------+---------+------------+----------+------------+----------------------------------------------+
2 rows in set (0.486 sec)

MariaDB [tpch]> notee