Migrations in a strict relation database always guarantee correctness. It's the need to roll back that causes issues. That is solved by not doing destructive c

Migrations in a strict relation database always guarantee correctness. It's the need to roll back that causes issues. That is solved by not doing destructive changes (removing a column) until the software is stable and a few iterations have passed. The issue of downtime is semi-valid but can likewise be worked around by batch migrating data in manageable chunks vs nuking.