Following table has two attributes Employee_ID and Manager_id, where Employee_id is a primary key and Manager_id is a foreign key referencing Employee_id with on-delete cascade:
|
Employee_id |
Manager_id |
|
20 |
40 |
|
25 |
40 |
|
30 |
35 |
|
35 |
20 |
|
40 |
45 |
|
45 |
25 |
On deleting the table (20,40), the set of other tuples that must be deleted to maintain the referential integrity of table is
1
(30,35) only
2
(30,35) and (35,20) only
3
(35,20) only
4
(40,45) and (25,40) only