InnoDB and MySQL Replication Query OK, 3 rows affected (0.19 sec) Records: 3 Duplicates: 0 Warnings: 0 At this point, on both the source and the replica, table  fc1  contains 2 rows, and table  fc2  contains 3 rows, as shown here: source>  SELECT * FROM fc1; +---+------+ | i | j | +---+------+ | 1 | 1 | | 2 | 2 | +---+------+ 2 rows in set (0.00 sec) source>  SELECT * FROM fc2; +---+------+ | m | n | +---+------+ | 1 | 1 | | 2 | 2 | | 3 | 1 | +---+------+ 3 rows in set (0.00 sec) replica>  SELECT * FROM fc1; +---+------+ | i | j | +---+------+ | 1 | 1 | | 2 | 2 | +---+------+ 2 rows in set (0.00 sec) replica>  SELECT * FROM fc2; +---+------+ | m | n | +---+------+ | 1 | 1 | | 2 | 2 | | 3 | 1 | +---+------+ 3 rows in set (0.00 sec) Now suppose that you perform the following  DELETE  statement on the source: source>  DELETE FROM fc1 WHERE i=1; Query OK, 1 row affected (0.09 sec) Due to the cascade, table  fc2  on the source now contains only 1 row: source>  SELECT * FROM fc2; +---+---+ | m | n | +---+---+ | 2 | 2 | +---+---+ 1 row in set (0.00 sec) However, the cascade does not propagate on the replica because on the replica the  DELETE  for  fc1 deletes no rows from  fc2 . The replica’s copy of  fc2  still contains all of the rows that were originally inserted: replica>  SELECT * FROM fc2; 3351