Database-Management-System

Question 45

Consider a relation geq which represents “greater than or equal to”, that is, (x,y) ∈ geq only if y >= x.

create table geq
(  Ib integer not null
   ub integer not null
   primary key 1b
   foreign key (ub) references geq on delete cascade )

Which of the following is possible if a tuple (x,y) is deleted?

A	A tuple (z,w) with z > y is deleted
B	A tuple (z,w) with z > x is deleted
C	A tuple (z,w) with w < x is deleted
D	The deletion of (x,y) is prohibited

Correct Answer: C