I have been running a big Rails application for over 2 years and, day by day, my ActiveRecord migration folder has been growing up to over 150 files.
There are very old models, no longer available in the application, still referenced in the migrations. I was thinking to remove them.
What do you think? Do you usually purge old migrations from your codebase?
Why? Unless there is some kind of problem with disk space, I don't see a good reason for deleting them. I guess if you are absolutely certain that you are never going to roll back anything ever again, than you can. However, it seems like saving a few KB of disk space to do this wouldn't be worth it. Also, if you just want to delete the migrations that refer to old models, you have to look through them all by hand to make sure you don't delete anything that is still used in your app. Lots of effort for little gain, to me.