Relational Algebra Concepts Worksheet

A company stores employee details in relation EMPLOYEE(name, dept, salary). To display only names and departments, which operation is used?

• Selection

• Projection

• Join

• Cartesian Product

To find all employees earning more than $50,000, which relational algebra operation should be applied?

• Selection

• Division

• Union

• Renaming

You have two relations: FULL_TIME_EMP and PART_TIME_EMP. To retrieve employees who are full-time but not part-time, which operation should be used?

• Union

• Difference

• Cartesian Product

• Selection

An analyst wants to rename the attribute "emp_name" in EMPLOYEE to "name" to standardize queries. Which operation should be applied?

• Projection

• Join

To merge student data from two distinct relations STUDENT_A and STUDENT_B with the same structure, you would use:

• Join

• Union

• Division

• Cartesian Product

Two relations contain students enrolled in “Database” and “Networking.” You want a list of students enrolled in both. Which operation gives the common result set?

• Difference

• Projection

• Intersection

• Selection

A professor wants to retrieve all students who registered for every available course. Which relational algebra operation is best suited for this scenario?

• Cartesian Product

• Division

• Projection

• Union

To generate a combined view of all courses and all instructors (regardless of any match), which join operation should be used?

A query connects STUDENT(sid, name) and ENROLL(sid, course) based on the matching ‘sid’. Which operation fits this use case?

• Cartesian Product

• Selection

• Equi Join

• Difference

To generate all possible combinations between CUSTOMER and PRODUCT relations without any condition, which operation would you apply?

• Join

• Cartesian Product

• Union

• Projection