database management system

 

  

d. Cluster Index e. Bitmap Index 7. A transaction T obtained a lock on a data item and prevent others to gain lock on the same data item. The lock mode that is being held by transaction T is a. Exclusive mode b. Write mode c. Shared mode d. Read mode e. All mode 8. Choose the right statement from the following schedules T read (A) A := A-50 write (A) read (B) B = B+50 write (B) commit T read (A) temp := A* 0.1 A := A - temp write (A) read (B) B := B + temp write (B) commit Schedule 1 T T read (A) A == A-50 write (A) read (B) a. Schedule 1 will not produce the same result as Schedule 2 b. Schedule 2 is conflict serializable B := B+50 write (B) commit read (A) temp = A* 0.1 A := A-temp write (A) read (B) B := B + temp write (B) commit Schedule 2 C. Schedule 1 is conflict equivalent with Schedule 2 d. Schedule 1 and Schedule 2 have deadlock e. No correct answer can be found 9. Schedule S contains two transactions, which are T1 and T2. When transaction T1 issues Lock-X(B), which statement is not true regarding this event? a. Transaction T2 cannot obtain Lock-S(B) if Transaction T1 has not started updating the value. b. Transaction T2 cannot overtake Lock-X(B) if Transaction T2 has more activities to do than T1 Transaction T2 cannot obtain the lock-S(B) C. d. Lock for object B is not shareable among multiple transactions e. If transaction T1 holds too many locks on objects, the concurrency-control manager will unlock some of the objects. 10. In B+Tree, the leaf pointer is used to a. Indicate the splitting point b. Get the next value in range search c. Identify the root d. Provide direct pointer to the data e. Remove the data when needed