Relational algebra is the formal language of the relational model. It defines a set of closed operations over relations, that is, the result of each operation is a new relation. Relational algebra inherits many operators from set algebra. Relational algebra operations could be categorized into two groups:
SET DIFFERENCE, and
CARTESIAN PRODUCT, also known as
Relational algebra operations could also be classified as binary and unary operations. Primitive relational algebra operators have ultimate power of reconstructing ...