Q1 A file of 4096 blocks is to be sorted with an available buffer space of 64

blocks. How many passes will be needed in the merge phase of the external

sort-merge algorithm?

Q2 Consider the following SQL query

SELECT E.Lname AS Employee_name, S.Lname AS Supervisor_name

FROM EMPLOYEE AS E, EMPLOYEE AS S

WHERE E.Super_ssn=S.Ssn;

ADraw at least two query trees that can represented each of that query.

Under what circumstances would you use each of your query trees?

BDraw the initial query tree for each of that query; then show how the

query tree is optimized by the algorithm outlined in section 19.7.

CCompare your on-query trees of part (a) and the initial and

final query trees of part (b).