Is ar_internal_metadata table created in production?

Question

I'm wondering if I need to create a migration for creating ar_internal_metadata in production on Rails 5

Answer 1

It's basically a safety switch, at the expense of complicating and changing how Rails apps are deployed:

Rails 5 has added a new table ar_internal_metadata to store environment version which is used at the time of migrating the database.

When the first time rake db:migrate is executed then new table stores the value production. Now whenever we load database schema or database structure by running rake db:schema:load or rake db:structure:load Rails will check if Rails environment is production or not. If not then Rails will raise an exception and thus preventing the data wipeout.

Source: http://blog.bigbinary.com/2016/06/07/rails-5-prevents-destructive-action-on-production-db.html