Consider the following sequence of actions, listed in the order they are submitted to the DBMS. r_1 (x) w_2 (x) w_2 (y) w_3 (y) w_1 (y) c_1 c_2 c_3. For each of the following concurrency control (cc) mechanisms, describe how the cc mechanism handles the sequence. Assume that the timestamp of transaction T_i is i. For lock-based cc mechanisms, add lock and unlock requests to the sequence as per the locking protocol. The DBMS processes actions in the order shown. If a transaction is blocked, assume that all the actions are queued until it is resumed; the DBMS continues with the next action (according to the listed sequence) of an unblocked transaction. Strict 2PL with timestamps used for deadlock prevention. Use both Wound-wait and Wait-die methods. Smaller timestamp means older transaction. Strict 2PL with deadlock detection. Show the wait-for graph in case of deadlock. Conservative and Strict (that is, with locks held until end of transaction) 2PL. Timestamp Concurrency control