When I did DB migrations, I first tested out my code on a test server that had a copy of the production database so see how well it would go and if there were a

When I did DB migrations, I first tested out my code on a test server that had a copy of the production database so see how well it would go and if there were any problems. I would test out all code on a test server first before putting it on a production server. Migrations were usually scheduled at Midnight and finished before anyone came into work. Before the Migration a backup of all data was done. It is the only safe way to do things.