Aspire's Library

A Place for Latest Exam wise Questions, Videos, Previous Year Papers,
Study Stuff for MCA Examinations - NIMCET

Previous Year Question (PYQs)

Consider the following schedule S.
 T1T2T3 T4 Timestamp 
 R(X) R(Y)  t1 
 W(X) W(Y)  t2 
R(Y)   R(X) t3 
W(Y)   W(X) t4 
  R(X)  t5 
  W(X)  t6 
(R(X)) denotes the read operation on data item X by transaction Ti. W(X) denotes write operation on data item X by transaction Ti. Choose the correct execution order for the above schedule S.




Solution

For data item $X$:

$T2$ writes $X$ before $T4$ reads and writes $X$.

So,

$T2 \to T4$

$T4$ writes $X$ before $T3$ reads and writes $X$.

So,

$T4 \to T3$

For data item $Y$:

$T3$ writes $Y$ before $T1$ reads and writes $Y$.

So,

$T3 \to T1$

Therefore, the serial order is:

$T2 \to T4 \to T3 \to T1$

Correct option is:

$\boxed{(c)\ T2-T4-T3-T1}$


Online Test Series,
Information About Examination,
Syllabus, Notification
and More.

Click Here to
View More

Online Test Series,
Information About Examination,
Syllabus, Notification
and More.

Click Here to
View More
Ask Your Question or Put Your Review.

loading...