Good points, I am familiar with the process. There is a concept or "forward-compatible change". Basically, you don't do things that will break your software.

Good points, I am familiar with the process. There is a concept or "forward-compatible change". Basically, you don't do things that will break your software. Example, you don't add a NOT-NULL column unless you can give it a good DEFAULT value, to make it work. Also dont' drop columns until the software is ready for it, etc. If you have a decent ORM, it will compare your "how it needs to be" sql schema with the "how it is" schema. Then it will generate appropriate "ALTER TABLE ...." "CREATE INDEX " etc statements. Note that this is automated and you never need to type SQL statements to achieve that. All together in the last XXX years, I did not really need to do a rollback on a dml statement.