Question

Consider the following relations:

Emp(eid: integer, ename: varchar, sal: integer, age: integer, did: integer) Dept(did: integer, budget: integer, floor: integer, mgr_eid: integer) Salaries range from $10,000 to $100,000, ages vary from 20 to 80, each department has about five employees on average, there are 10 floors, and budgets vary from $10,000 to $1 million. You can assume uniform distributions of values. For each of the following queries, which of the listed index choices would you choose to speed up the query.
1. Query: Print ename, age, and sal for all employees.
A) Clustered hash index on fields of Emp.
B) Unclustered hash index on fields of Emp.
C) Clustered B+ tree index on fields of Emp.
D) Unclustered hash index on fields of Emp.
E) No index.
2. Query: Find the dids of departments that are on the 10th floor and have a budget of less than $15,000.
A) Clustered hash index on the floor field of Dept.
B) Unclustered hash index on the floor field of Dept.
C) Clustered B+ tree index on fields of Dept.
D) Clustered B+ tree index on the budget field of Dept.
E) No index.

Answer 1

Check the explanation

Step-by-step explanation:

--Query 1)

SELECT ename, sal, age

FROM Emp;

--Query 2)

SELECT did

FROM Dept

WHERE floot = 10 AND budget<15000;