Consider the following query:

SELECT E.EmpName
FROM EMPLOYEE E
JOIN DEPARTMENT D
  ON E.DeptID = D.DeptID
WHERE D.DeptName = 'Sales';

Assume that an index exists on DEPARTMENT.DeptName, an index exists on EMPLOYEE.DeptID, and only a small number of departments satisfy the condition. Which strategy is likely to be efficient?

Tuple relational calculus is a Answer Question 12 query language because it specifies what data is required rather than the sequence of operations used to retrieve it.

Consider the following SQL queries A and B 

Query A :

select distinct course_id

from section

where semester = 'Fall' and year= 2017 and

course_id in (select course_id

from section

where semester = 'Spring' and year= 2018)

Query B:

select distinct course_id

from section

where semester = 'Spring' and year= 2017 and

course_id in (select course_id

from section

where semester = 'Fall' and year= 2018)

Which statement best describes dynamic hashing?

The heuristic rule that pushes a selection operation as close as possible to the base relation is called Answer Question 9 of selection.

In cost estimation for query processing, which cost component is generally considered the dominant factor and often used as the main metric?

Consider the following statements and determine whether they are ture or false

Why is a multi-level index useful when a single-level index becomes very large?

What is the primary purpose of an index in a database file?

Consider the following statements and determine whether they are ture or false