1. Describe alternative schemes for fragmenting a global relation. State how you would check for correctness to ensure that the database does not undergo semantic change during fragmentation. 2. What layers of transparency should be provided with a DDBMS? Give examples to illustrate your answer. Justify your answer. 3. How data distribution affects the transaction management protocols. 4. Compare 2PC and 3PC protocols in distributed environments. 5. Consider following relations EMP (ENO, ENAME, TITLE) ASG (ENO, PNO, RESP, DUR) PROJ (PNO, PNAME, BUDGET, LOC) Convert following query into relational algebra query and draw (i) canonical tree (ii) transform canonical tree into optimal tree. Select ENAME, PNAME From EMP a, ASG b, PROJ c Where a.ENO = ASG.ENO And b.PNO = c.PNO And (TITLE = 'Elec. Eng" or b.PNO < "P5"