Selection

Relational Algebra Symbols

Unary Operators

Selection   

Projection  

Aggregate Function 

Binary Operators

Union 

Intersection 

Difference 

Cartesian product 

Theta Join

Natural Join * (or in some notations )



Left Outer Join

Right Outer Join

Full Outer Join

Outer Union *

Logic Symbols



Logical AND 



Logical OR 



Logical NOT 