a) Three relations are given to you, R1(A, B, C), R2(C, D, E), and R3(E, F). The primary keys for R1, R2 and R3 are A, C, and E, respe number of tuples in R1 is 400, R2 has 700 tuples, and R3 has 1200...

Extracted text: a) Three relations are given to you, R1(A, B, C), R2(C, D, E), and R3(E, F). The primary keys for R1, R2 and R3 are A, C, and E, respe number of tuples in R1 is 400, R2 has 700 tuples, and R3 has 1200 tuples. What will be the estimate size of RI R2 MR3, b) What is a query execution plan? Find the inner block and outer block of the following SQL query and write the corresponding extende expression for the inner block and outer block as well. SELECT Fname, Lname FROM EMPLOYEE WHERE Salary > ( SELECT MIN (Salary) FROM EMPLOYEE WHERE Dno=6 ); c)Discuss how left deep trees and dynamic programming help in cost-based optimization.