Q. 22 A hard disk has 63 sectors per track, 10 platters each with 2 recording surfaces
and 1000 cylinders. The address of a sector is given as a triple c,h, s , where c is
the cylinder number, h is the surface number and s is the sector number. Thus,
the 0th sector is addressed as 0,0,0 , the 1st sector as 0,0,1 , and so on.
Consider two transactions T1 and T2 and four schedules S1,S2,S3,S4 of T1 and T2 as
given below :
T1 = R1[X] W1[X] W1[Y] T2 = R2[X] R2[Y] W2[Y] S1 = R1[X] R2[X] R2[Y] W1[X] W1[Y] W2[Y] S2 = R1[X] R2[X] R2[Y] W1[X] W2[Y] W1[Y] S3 = R1[X] W1[X] R2[X] W1[Y] R2[Y] W2[Y] S1 = R1[X] R2[Y]R2[X]W1[X] W1[Y] W2[Y]
Which of the above schedules are confl ict-serializable?
(A) S1 and S2
(B) S2 and S3
(C) S3 only
(D) S4 only
Answer: (B)
Explanation:
