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 ranges from 10000 to 100000 ages vary from 20 to 80, each department has about five employees on average, there are 10 floors, and budgets vary from 10000 too 1 million. You can assume uniform distribution of values.
For following query, which of the listed index choices would you choose to speed up the query?
Query:Find the dids of departments that are on the 10th floor and have a budget of less than 15000
(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 (floor, budget) fields od Dept
(D) Clustered B+ tree index on the budge field of Dept
I feel in first paragraph what all important is Dept table.