Getting Started with PostgreSQL - PostgreSQL Developer's Guide - page 13

You can then see from the following truth table how data type a can result in a
different value when used with the NOT logical operator:

a NOT a

TRUE FALSE

FALSE TRUE

NULL NULL

Comparison operators
In PostgreSQL, we have the following comparison operators, as shown in the
following table:

Operator Description

< Less than

> Greater than

<= Less than or equal to

>= Greater than or equal

to

= Equal

<> or != Not equal

Mathematical operators
PostgreSQL also provides you with the following mathematical operators, as you can
see in the following table:

Operator Description

+ Addition

- Subtraction

* Multiplication

/ Division

% Modulo (Remainder)

^ Exponentiation

|/ Square root

||/ Cube root

! Factorial

!! Factorial (prefix operator)