This comes from a class on databases
This comes from a class on databases (c) Transaction Processing Consider the following schedule: transaction TI...
-Advanced Database- Consider the following transaction schedule, where time increases from top to bottom. T1 T2 T3 T4 Read (X) Read(Y) Read(Z) Read(Y) Write(Y) Write(Z) Read(U) Read(Y) Write(Y) Read(Z) Write(Z) Read(U) Write(U) Answer the following questions: Draw the precedence graph of the above schedule. Is this schedule conflict serializable? If yes, show what serial schedule(s) it is equivalent to. If not, explain why. Is this schedule view serializable? If yes, show what serial schedule(s) it is equivalent to. If not,...
1. Consider the following schedule S TI T2 read(A) write(A write(A) write(A (a) Draw the precedence graph of S (b) Is schedule S serializable? If so, name one equivalent serial schedule, and prove equivalence (c) Denote by S"the schedule obtained by replacing the write(A) in T2 with read(A) in S. Is schedule S" serializable? If so, name one equivalent serial schedule and prove equivalence. Otherwise prove that it is not. (d) Denote by S"the schedule obtained by replacing the write(A)...
For the system given in figure 3 identify if schedule 2 is conflict equivalent and view equivalent to schedule 1. Give proper reasons for you answer. Resolve the issues in schedule 2 by adopting appropriate locking scheme and apply deadlock prevention scheme to ensure prevention of deadlocks and starvation. (7) Table 2:Serial Schedule 1 T1 T2 T3 T4 T5 Read(X) Read(Z) Read(Y) Write(Z) ...
1. What is the difference between Two-Phase Locking (2PL) and Strict Two-Phase Locking? What condition to Strict 2PL prevent that 2PL does not prevent? 2. What are deadlocks? What are two techniques for detecting and resolving deadlocks? 3. In the figure below, R(X, y) means read database item X into variable y and W(X, y) means write variable y into database item y. Column T1 shows transaction T1's operations and column T2 shows T2's operations. Columns Aand_B show the values...
Consider the following transaction schedule: r1(X), r2(X), r3(X), r1(Y), w2(Z), r3(Y), w3(Z), w1(Y) This schedule is conflict-equivalent to some or all serial schedules. Determine which serial schedules it is conflict-equivalent to, and then identify a true statement from the list below. Select one: a. The schedule is conflict-equivalent to (T3, T1, T2) b. The schedule is not serial c. The schedule is conflict-equivalent to (T3, T2, T1) d. The schedule is conflict-equivalent to (T2, T3, T1) e. The schedule is...
Q5: In DBMS, a graph precedence is used to test whether a schedule of concurrent transactions is conflict serializable or not. Given the following schedule S with three transactions T T3 T2 read(A) read(B) write(A) read(A) write(B) write(A) read(B) write(B) 1. Draw the precedence graph for the schedule S (5 points) 2. Check whether the schedule S conflict serializable or not (5 points] 3. Is it possible to construct a serial schedule S'which is conflict equivalent to the schedule S?...
2. Given the following three transactions T1 = r1(x); w1(y); T2 = r2(z); r2(y); w2(y); w2(x); T3 = r3(z); w3(x); r3(y); Consider the schedule S = r1(x); r3(z); r2(z); w3(x); r2(y); r3(y); w2(y); w1(y); w2(x); a. Draw the precedence graph of schedule S, and label each edge with data item(s). b. Based on the precedence graph, determine whether S is conflict serializable and justify your answer. If it is serializable, specify all possible equivalent serial schedule(s).