Consider the following four schedules due to three transactions (indicated by the subscript) using read and write on a data item X, denoted by r(X) and w(X) respectively. Which one of them is conflict serializable ?S1 : r1(X); r2(X); w1(X); r3(X); w2(X)S2 : r2(X); r1(X); w2(X); r3(X); w1(X)S3 : r3(X); r2(X); r1(X); w2(X); w1(X)S4 : r2(X); w2(X); r3(X); r1(X); w1(X)

Consider the following four schedules due to three transactions (indic

1.	Consider the following four schedules due to three transactions (indicated by the subscript) using read and write on a data item X, denoted by r(X) and w(X) respectively. Which one of them is conflict serializable ?S1 : r1(X); r2(X); w1(X); r3(X); w2(X)S2 : r2(X); r1(X); w2(X); r3(X); w1(X)S3 : r3(X); r2(X); r1(X); w2(X); w1(X)S4 : r2(X); w2(X); r3(X); r1(X); w1(X)
A.	S1
B.	S2
C.	S3
D.	S4
Answer» E.

Discussion

No Comment Found

Related MCQs

Which of the following is not a type of a schedule?
If a schedule is equivalent to a serial schedule, it is called as a _________
_____ occurs when two transactions that access the same database items have their operations interleaved in a way that makes the value of some database items incorrect.
Consider the following log sequence of two transactions on a bank account, with initial balance 12000, that transfer 2000 to a mortgage payment and, then apply a 5% interest(i) T1 start(ii) T1 B old = 12000 new = 10000(ii) T1 M old = 0 new = 2000(iv) T1 commit(v) T2 start(vi) T2 B old = 10000 new = 10500(vii) T2 commitSuppose the database system crashed just before log record 7 is written. When the system is restarted, which one statement is true of the recovery procedure?
In Database management system ACID property refers to:
Consider the following four schedules due to three transactions (indicated by the subscript) using read and write on a data item x, denoted by r(x) and w(x) respectively. Which one of them is conflict serializable?
Consider the following partial Schedule S involving two transactions T1 and T2. Only the read and the write operations have been shown. The read operation on data item P is denoted by read(P) and the write operation on data item P is denoted by write(P)Time InstanceTransaction-idT1T21read(A) 2write(A) 3 read(C)4 write(C)5 read(B)6 write(B)7 read(A)8 Commit9read(B) Schedule S Suppose that the transaction T1 fails immediately after time instance 9. Which one of the following statements is correct?
Consider the following database schedule with two transactions, T1 and T2.S = r2(X); r1 (X); r2(Y); w1(X); r1 (Y); w2(X); a1; a2where ri(Z) denotes a read operation by transaction Ti on a variable Z, wi(Z) denotes a write operation by Ti on a variable Z and ai denotes an abort by transaction Ti.Which one of the following statements about the above schedule is TRUE?
Consider the transactions T1, T2, and T3 and the schedules S1 and S2 given below.T1: r1(X); r1(Z); w1(X); w1(Z)T2: r2(Y); r2(Z); w2(Z)T3: r3(Y); r3(X); w3(Y)S1: r1(X); r3(Y); r3(X); r2(Y); r2(Z); w3(Y); w2(Z); r1(Z); w1(X); w1(Z)S2: r1(X); r3(Y); r2(Y); r3(X); r1(Z); r2(Z); w3(Y); w1(X); w2(Z); w1(Z)Which one of the following statements about the schedules is TRUE?
ACID properties of a transactions are

Discussion

No Comment Found

Related MCQs

Reply to Comment