MariaDB [federated]> explain DELETE 
    -> 
    -> FROM 
    -> 
    ->   OUTR1 USING D AS OUTR1 
    -> 
    ->   RIGHT JOIN 
    -> 
    ->   ( B AS OUTR2 JOIN D AS OUTR3 ON ( OUTR2.pk > OUTR3.col_int_key ) )
    -> 
    ->     ON ( OUTR1.col_int_nokey = OUTR2.col_int_key ) 
    -> 
    -> WHERE 
    -> 
    ->   OUTR1.col_int_key IN (  SELECT DISTINCT INNR1.pk 
    -> 
    ->                           FROM CC AS INNR1 
    -> 
    ->                           WHERE INNR1.col_int_nokey <= 1 OR NOT INNR1.pk > 4 
    -> 
    ->                         UNION DISTINCT 
    -> 
    ->                           SELECT INNR1.pk 
    -> 
    ->                           FROM AA AS INNR1 
    -> 
    ->                           GROUP BY INNR1.col_int_uniq 
    -> 
    ->                           HAVING COUNT(*) >= 2
    -> 
    ->                        );
+------+--------------------+------------+--------+---------------+---------+---------+------+------+------------------------------------------------+
| id   | select_type        | table      | type   | possible_keys | key     | key_len | ref  | rows | Extra                                          |
+------+--------------------+------------+--------+---------------+---------+---------+------+------+------------------------------------------------+
|    1 | PRIMARY            | OUTR2      | index  | PRIMARY       | k_int   | 5       | NULL | 100  | Using index                                    |
|    1 | PRIMARY            | OUTR1      | ALL    | NULL          | NULL    | NULL    | NULL | 100  | Using where                                    |
|    1 | PRIMARY            | OUTR3      | ALL    | k_int         | NULL    | NULL    | NULL | 100  | Range checked for each record (index map: 0x4) |
|    2 | DEPENDENT SUBQUERY | INNR1      | eq_ref | PRIMARY       | PRIMARY | 4       | func | 1    | Using where                                    |
|    3 | DEPENDENT UNION    | INNR1      | index  | NULL          | u_int   | 5       | NULL | 1    | Using index                                    |
| NULL | UNION RESULT       | <union2,3> | ALL    | NULL          | NULL    | NULL    | NULL | NULL |                                                |
+------+--------------------+------------+--------+---------------+---------+---------+------+------+------------------------------------------------+
6 rows in set (0.001 sec)

MariaDB [federated]> notee;