1 1 vote Consider a relation R(A,B) where A is the primary key and B is a foreign key which references the same relation. Consider the following relation instance of R. A 2 3 5 7 4 3 B 4 4 2 2 5 4 Which of the following tuple to be deleted first to preserve the referential integrity constraint when the tuple (2,4) is deleted. Databases databases + – Utsav09 653 views answer comment Share Follow Print See all 3 Comments 3 3 Comments reply sumit chakraborty commented Jan 27, 2018 reply Follow flag (5,2) , (7,2) ,(4,5) should be deleted to preserve the integrity. 0 0 replyShare Utsav09 commented Jan 28, 2018 reply Follow flag (4,5) is to be deleted first? 1 1 replyShare sumit chakraborty commented Jan 28, 2018 reply Follow flag (4,5) will be deleted last. First to preserve the integrity (5,2) and (7,2) will be deleted because primary key 2 is no longer there, then because of this 5 and 7 are no more there then again to preserve integrity (4,5) is deleted. 0 0 replyShare Please log in or register to add a comment.
