I’ve always felt that Rails migrations came up short in the area of data seeding and data migration. While you can use the standard schema migrations to manage your data it is a recipe for disaster.
From the README file:
"ActiveDataMigrations is a Ruby gem that allows developers to set up multiple migration locations, each of which can be run independent of one another. This library sits on top of ActiveRecord so all standard migration features remain available.
This is particularly useful in cases where you want to separate your data migrations from your schema migrations or where you have multiple steps in your migration process that must have other steps invoked throughout."