Consider the following schedule. Explain what happens when transactions try to execute as per this schedule and the DBMS uses basic timestamp-based concurrency control. When a transaction T is aborted, remember to rollback T.

R2(X) ? R1(X) ? W2(X) ? W4(X) ? W1(X) ? C1 ? W3(X) ? A4 ? R2(Y ) ? W2(Y ) ? R3(Y ) ? C2 ? W3(Y ) ? C3.

RT is Read_TS(), WT is Write_TS()

TS(T1) = 1, TS(T2) = 2, TS(T3) = 3 and TS(T4) = 4.

Answer (Fill in the table below showing what happens as the transactions execute all the way to C3):

T1	T2	T3	T4	X	Y
				RT = 0, WT = 0	RT = 0, WT = 0
	R2(X)			RT = 2, WT = 0	RT = 0, WT = 0