Question 1
Consider the following schedule for transactions T1, T2 and T3:
[caption width="800"] [/caption]Which one of the schedules below is the correct serialization of the above?
Question 2
Question 3
Question 4
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?
Question 5
1. T1 start 2. T1 B old=12000 new=10000 3. T1 M old=0 new=2000 4. T1 commit 5. T2 start 6. T2 B old=10000 new=10500 7. T2 commitSuppose the database system crashes just before log record 7 is written. When the system is restarted, which one statement is true of the recovery procedure?
Question 6
S = T1:R(x), T1:R(y), T1:W(x), T2:R(y), T3:W(y), T1:W(x), T2:R(y)
Question 7
Question 8
Question 9
read(x); x := x – 50; write(x); read(y); y := y + 50; write(y)The constraint that the sum of the accounts x and y should remain constant is that of
Question 10
(start, T4); (write, T4, y, 2, 3); (start, T1); (commit, T4); (write, T1, z, 5, 7); (checkpoint); (start, T2); (write, T2, x, 1, 9); (commit, T2); (start, T3); (write, T3, z, 7, 2);If a crash happens now and the system tries to recover using both undo and redo operations, what are the contents of the undo list and the redo list
There are 48 questions to complete.