Functions

PostgreSQL offers that help us generate test data for testing purposes.

random() generates a random function between 0-1

repeat('text',5) repeats the word text 5 times horizontally

generate_series(1,5) generates 5 rows with values 1,2,3,4,5.

here is an example query

	SELECT hello.txt || trunc(random()*100000) || repeat(mammoth,10) || generate_series(1,5);

The Official Documentation has more information on other functions as well.