Build the parse tree for the following queries and optimize them using the rewrite rules. Given the relations:

a)

SELECT startname

FROM Germanmovies NATURAL JOIN startsin

WHERE Director = 'ABCDEF'

[note germanmovies is a view as shown below]:

CREATE VIEW germanMovies AS

SELECT *

FROM movie

WHERE language = 'german';

b)

SELECT dept_name

FROM dept, manager

WHERE Manager.DNO =Dept.DNO AND Manager.salary = 50000;