Q-4-4 - Read the following scenario and address the following issues that are related to transaction and concurrency control.

Assume that objects a1, a2, and a3 are managed by a server, which provides two operations to operate the objects.

read(a): returns the value of object a

write(a, v): assigns the value v to object a

Assume that the following two concurrent transactions T and U are performed on these objects.

T: read(a2); read(a1); write(a2, a2-25); read(a3); write(a1, a1+52)

U: read(a3); read(a2); write(a2, a2+33); write(a3, a3-26)

Assume that the original values of a1, a2, and a3 are 111, 106 and 125 respectively. Answer the following questions based on the above scenario.

Question : Give an example of possible interleaving operations that can produce the correct values of a1, a2 and a3. Note: no marks is given to this question if the operations are not interleaved.