Relational Algebra

Basic Operations in Relational Algebra

Select

• The select operation is used for selecting a subset of tuples from a relation that satisfy a selection condition.
• Example: σ_age>30 (Employee) selects all employees older than 30.

Project

• The project operation is used for choosing required columns from a relation.
• Example: π_name,age (Employee) selects name and age columns from Employee table.

Union

• The union operation combines tuples from two relations and eliminates duplicate tuples.
• Example: Employee ∪ Manager shows all records from both Employee and Manager tables.

Set Difference

• The set difference operation shows tuples that are in one relation but not in the other.
• Example: Employee - Manager shows records that are in the Employee table but not in the Manager table.

Cartesian Product

• The cartesian product operation combines tuples from two relations.
• Example: Employee x Department shows all possible combinations of Employee and Department records.

Additional Operations in Relational Algebra

Rename