Rails 7.0 adds encryption to Active Record models
Rails 6.1 adds delegated_type to ActiveRecord
Rails 6.1 adds support for PostgreSQL interval data type
Ruby 3 adds new method Hash#except
Ruby 3 adds endless method definition
Rails 6 adds including & excluding method on Enumerables
Rails 6.1 creates abstract classes in multiple database mode
Rails 6.1 adds annotate_rendered_view_with_filenames for views
Ruby 2.7 adds Enumerable#tally
Rails 6 adds rails db:prepare to migrate or setup a database
Rails 6 adds ActiveStorage::Blob#open