Subject: Distributed Databasebe

Please solve all parts as this is single qs and both parts are related. Solve it when you are sure about both.

Q.No.3. (Marks 10)

A.

Draw query graph and join graph for the given query

SELECT ENAME, RESP

FROM EMP, ASG, PROJ

WHERE EMP.ENO = ASG.ENO

AND ASG.PNO = PROJ.PNO

AND PNAME = "CAD/CAM"

AND DUR 36

AND TITLE = "Programmer"

B.

Simplify the given query

SELECT TITLE

FROM EMP

WHERE EMP.ENAME = "J. Doe"

OR (NOT (EMP.TITLE = "Programmer")

AND (EMP.TITLE = "Programmer"

OR EMP.TITLE = "Elect. Eng.")

AND NOT (EMP.TITLE = "Elect. Eng."))

C.

Make query tree for the given query and also identify project, select and join

SELECT ENAME

FROM EMP, ASG, PROJ

WHERE EMP.ENO = ASG.ENO

AND ASG.PNO = PROJ.PNO

AND ENAME "J. Doe"

AND PNAME = "CAD/CAM"

AND (DUR = 12 OR DUR = 24)