Relational Algebra
Relational Algebra
Relational Algebra provides a collection of Algebraic operations that operate on relations(or tables) and it gives output result in the form of tables.
Operation  Symbol 
Descriptions 

1  SELECT 
σ  Select those tuples that satisfy the given Predicate 
2  PROJECT  π  Gives the content of the given Relation 
3  UNION  U  Combine all rows from the given two table 
4  SET DIFFERENCE    Given two tables, this gives tuples that are in table 1 but are not in table2 
5  CARTESIAN PRODUCT 
χ  Gives list of all pairs of rows from two tables 
6  RENAME  ρ 
Gives a name to the result of relational algebra expressions, we can refer the result with this name 
7  SET INTERSECTION 
∩  List rows that appear in both tables 
8  JOIN  Combine information from two or more tables  
9  DIVISION  ÷  
10  ASSIGNMENT 
←  It is used to store the result of Relational Algebraic expression in temporary variables. 