Consider the following relational schema:

Emp(eid:integer, ename:string, age:integer, salary:real)

Works(eid:integer, did:integer, pc time:integer)

Dept(did:integer, dname:string, budget:real, managerid:integer)

The bold attributes are keys for their relations. Note that a manager is an employee as well and their manager id and employee id are the same. An employee can work in more than one department. The pct time field of the Works relation shows the percentage of time that a given employee works in a given department. Write the following queries in SQL. Consider the following SQL queries:

Select * From Emp, Works Where 1< Emp.eid < 200 and salary < 20000 and Emp.eid = Works.eid

Select * From Emp, Works, Dept Where Emp.eid = Works.eid and Works.did = Dept.did and budget= 800000

List the attributes of the relations Emp, Works, Dept that if one indexes them, the running time of these queries will improve. Which ones are clustered and which ones are not? You must also write the type of index (B+ tree or hash) for each indexed attribute(s)