Exercises (chapter 19) For each of the following queries: a- Draw the query graph. b- Draw the query tree corresponding to the relational algebra expression. c- Draw the initial query tree, then show how the same query tree is optimized by heuristic rules optimization in another figure. Q 1: SELECT Fname, Lname, Address FROM EMPLOYEE, DEPARTMENT WHERE Dname='Research' AND Dnumber=Dno; Q 2: SELECT E.Fname, E.Lname, S.Fname, S.Lname FROM EMPLOYEE AS E, EMPLOYEE AS S WHERE E.Super_ssn=S.Ssn; Q 3: SELECT E.Fname, E.LName, E.Address FROM EMPLOYEE E, DEPARTMENT D WHERE D.DName ='Research' AND D.Dnumber=E.Dno; Q 4: SELECT Pnumber, Pname, COUNT (*) FROM PROJECT, WORKS_ON, EMPLOYEE WHERE Pnumber=Pno AND Ssn=Essn AND Dno=5 GROUP BY Pnumber, Pname