Relational Algebra is a set of basic operations used to manipulate the data in relational model. These operations can be classified in two categories:
1. Basic Set Operations
- Set Difference
- Cartesian Product
2. Relational Operations
If R1 and R2 are two union compatible relations then R3 = R1 ∪ R2 is the relation containing tuples that are either in R1 or in R2 or in both.
If R1 and R2 are two union compatible relations, then the result of R3 = R1 ∩R2 is the relation that includes all tuples that are in both the relations
If R1 and R2 are two union compatible relations then result of R3 =R1– R2 is the relation that includes only those tuples that are in R1 but not in R2.
If R1 and R2 are two functions or relations, then the result of R3 = R1 × R2 is the combination of tuples that are in R1 and R2.
Degree (R3) =Degree of (R1) + Degree (R2).