I have a table that looks like this:
Created at | Amount | Register Name
--------------+---------+-----------------
01/01/2019... | -150.01 | Front
01/01/2019... | 38.10 | Back
What is the best way to attach an ascending-by-date running total to each record which applies only to the register name the record has? I can do this in Ruby, but doing it in the database will be much faster as it is a web application.
The application is a Rails application running Postgres 10, although the answer can be Rails-agnostic of course.