Consider the following schedule S, which is generated by some concurrency control protocol for executing two transactions T1 and T2:

S = T1:W(X), T2:R(Y), T1:R(Y), T2:R(X), T1:Commit, T2:Commit

For each of the following concurrency control protocols, you must:

A. State if the protocol allows schedule S. That is, allows the actions to occur in exactly the order shown in schedule S.

B. Explain the reason why schedule S is allowed or not allowed under that protocol.

1) under the Basic 2PL protocol

2) under the Strict 2PL protocol

3) under the Conservative 2PL protocol