Consider the following tables T1 and T2:



In table T1, P is the primary key, Q is the foreign key referencing R in table T2 with on-delete cascade and on-update cascade. In table T2, R is the primary key and S is the foreign key referencing P in the table T1 with on-delete cascade and on-update cascade. In order to delete record (3, 8) from table, numbers of additional record that need to be deleted from table T1 is ________.
(A) 5
(B) 4
(C) 2
(D) 3


Answer: (C)

Explanation: If record (3, 8) from table T1 is deleted, then you need to delete record (8, 3) from table T2 in order to foreign key 3 in table T2 which refers primary key 8 in table T1.

Now, if you delete record (8, 3) from table T2, then you need to delete (5, 8) and (9, 8) from table T1 to preserve forign key 8 in table T1 which refers primary key in table T2.

Therefore, numbers of additional record that need to be deleted from table T1 is 2.

option (C) is correct.

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