A Look at Cartesian Products
Copyright 2012 by Shawn H Corey. Some rights reserved. Licence under CC BY-SA 3.0 Problem: You have a number of sets and you want all the combinations when choosing one element from each set. In mathematics, these combinations are called the Cartesian product . They are also known as cross-products. In the database world, they are sometimes called cross-joins. This article is to show how to create them using Perl's glob function and how to create them in a subroutine.