5. T1: Begin Transaction

Update R set Value Value + 1 where ID = 1;

Update R set Value Value + 1 where ID=2;

Update R set Value Value + 1 where ID = 3;

Commit;

T2: Select sum(Value) from R;

Commit;

Answer the following questions:

a. If transactions execute with read-uncommitted, what is the possible distinct values of T2

b. (1pts) if transactions execute with read-committed, what is the possible distinct values of T2:

c. (1pts) if transactions execute with repeatable-read, what is the possible distinct values of T2:

d. (1pts) if transactions execute with serializable, what is the possible distinct values of T2: