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Overview of Relational Algebra:

consists of a set of high level operators that operate on relations. Each of these operators take one or two relations as input and produces a new output ratio.

Codd defined a very specific set of eight operators of this type, in two groups:

Traditional Operations:

# Union: build a relationship consists of all tuples appear in any of the two relationships.

# Intersection: Build a relationship composed of those tuples that appear in both relationships.

# Difference: Make a connection formed by the tuples that appear in the first relationship that does not appear in the second of two specified relations.

Cartesian Product #: From two relationships, build a relationship that contains all possible combinations of tuples.

special relational operations:

# Restriction: extracts tuples specified in a given relationship. Extracts those tuples that satisfy the condition.

# Projection: extracts specified attributes of a given relationship.

# Meeting: From two relationships, build a relationship that contains all possible combinations of tuples, one from each of the two relationships.

# Division: It takes two relations, one binary and one unary, and build a relationship formed by all values \u200b\u200bof an attribute of the binary relation that match all the values \u200b\u200bof the unary relation.