I am not strong in DB knowledge, especially Postgresql. So the istuation is: I have two columns in a table num_bigger and num_lower. I need to make a third column that is
elapsed = num_bigger - num lower
I've googled it and figured out that the best way to do this is to make a view(Also I found how to do this using triggers, but they are not allowed for me). Any suggestions how to make this kind of view ?