Question

The following table has two attributes A and C where A is the primary key and C is the foreign key referencing A with on-delete cascade.
A C
2 4
3 4
4 3
5 2
7 2
9 5
6 4
The set of all tuples that must be additionally deleted to preserve referential integrity when the tuple (2,4) is deleted is:

(3,4) and (6,4)
(5.2) and (7,2)
(3,4), (4.3) and (6,4)
(5,2). (7.2) and (9.5)​

Answer 1

Explanation:

the action of linking things together in a series, or the condition of being linked in such a way.