1. Index Structures
Consider a relation Employees (eid, name, salary, age, did) stored as a heap file (unsorted) for which the only index is an unclustered index on a field called salary.
1. If you want to retrieve all records with salary > 50, is using the index always better than other alternatives?
2. What could be a problem if the index is sparse?
3. What will you recommend to change to make this index useful for both equality search (e.g., salary = 25) and range search ( e.g., 10 < salary < 30)?
4. If you need to add one more index on a field called name, can both of them sparse?
5. Can both of them clustered?