1.Consider schedules 53′ 54′ and 55 below. Determine whether each schedule is
strict, cascadeless, recoverable, or nonrecoverable. (Determine the strictest recoverability
condition that each schedule satisfies.)
53: rl (X); r2 (2); rl (2); r3 (X); r3 (Y); WI (X); CI; W3 (Y); C3; r2 (Y); W2 (2); W2 (Y); c2;
54: rl (X); r2 (2); r l (2); r3 (X); r3 (Y); WI (X); W3 (Y); r2 (Y); W2 (2); W2 (Y); CI; C2; c3;
55: rl (X); r2 (2); r3 (X); rl (2); r2 (Y); r3 (Y); WI (X); CI; W2 (2); W3 (Y); W2 (Y); C3; C2; 18.1. What is the two-phase locking protocol? How does it guarantee serializability!
- What are some variations of the two-phase locking protocol? Why is strict or rigorous
two-phase locking often preferred? 3. Discuss the problems of deadlock and starvation, and the different approaches to dealing with these problems. 4. Compare binary locks to exclusive/shared locks. Why is the latter type of locks preferable?