CS 5200 Introduction to Database Management Homework #10

Determine whether the following schedules are conflict-serializable, view-serializable or strict.

1. If the schedule is conflict-serializable, give an example of a serial order for the transactions. If the schedule is not conflict-serializable, explain why.
2. If the schedule is view-serializable, give an example of a serial order for the transactions. If the schedule is not view-serializable, explain why.
3. If the schedule is not strict, give an example of an operation that violates the strictness requirement. The definition of a strictness violation is a pattern of the following form:

   Wi(X) ... Opj ... Cj ... Ci
   

   where i and j are different transaction identifiers, and Op is either a read or a write. However, in fact, strict two-phase locking prevents any pattern of the following form:

   Wi(X) ... Opj ... Ci
   

   In your solution indicate whether you are using "strict" or "strict 2PL". The term for this form of strictness is "avoids cascading aborts".

1. R₄(B), R₁(A), R₁(B), W₃(B), W₂(C), C₁, R₄(A), R₂(A), C₂, R₃(C), R₄(A), C₄, W₃(C), W₃(A), C₃
2. R₃(C), R₁(C), R₃(A), W₂(B), W₂(A), W₄(A), C₂, R₁(C), W₄(B), C₃, C₄, C₁
3. W₁(C), W₂(C), R₂(C), C₂, W₁(C), R₄(B), W₄(A), R₃(B), R₃(C), C₄, R₁(B), R₃(A), C₁, W₃(C), C₃
4. R₁(C), R₁(B), R₂(B), R₃(C), W₄(B), W₄(A), C₁, C₄, R₂(C), R₃(B), W₂(C), C₂, R₃(A), W₃(A), R₃(A), C₃
5. W₂(C), R₁(B), R₂(B), C₂, W₃(A), R₃(C), R₁(B), W₁(C), R₁(B), R₁(C), C₁, W₃(A), C₃
6. W₃(A), W₃(B), R₂(B), R₂(C), R₃(B), C₃, W₂(A), R₁(B), W₂(A), C₂, W₁(A), W₁(B), R₁(C), C₁
7. R₂(A), W₃(A), W₂(A), R₃(B), W₁(C), W₁(A), C₂, C₁, C₃
8. R₁(C), R₃(A), R₁(A), W₃(A), C₃, R₂(C), R₁(C), W₁(C), R₂(B), R₂(A), C₂, C₁