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2.  Which of the following schedules is (conflict) serializable? For each serializable schedule, determine the equivalent serial schedules.

(a) w1 (X); r2 (X); w1(X); r3(X); w2(X)

(b) r1 (X); r3 (X); w2(X); w1(X); r3(X)

(c) w3 (X); r2 (X); w3(X); r1(X); w1(X)

(d) r3 (X); r1 (X); r2(X); w3(X); w2(X)

(e)  r1(x); r2(z); w3(x); r1(z); r2(y); r3(y); r1(x); w2(z); w3(y); w2(y)

(15 points)

3.Consider schedules S1, S2, and S3 below. Determine whether each schedule is strict, cascadeless, recoverable, or nonrecoverable. (Determine the strictest recoverability condition that each schedule satisfies.)

S1: w1(x); r2(z); r1(z); w3(x); r3(y); w1(x); c1; w3(y); c3; r2(y); w2(z); w2(y);c2

S2: r1(x); w2(z); r1(z); r3(x); r3(y); w1(x); w3(y); w2(y); w2(z); w2(y); c1; c2; c3;

S3: w1(x); r2(z); r3(x); r1(z); w2(y); r3(y); w1(x); w2(z); w3(y); w2(y); c3; c2;

(15 points)