You can see my sibling comment, but in the real world of operating databases at any sort of scale, you need to have databases in transitory states where the app

You can see my sibling comment, but in the real world of operating databases at any sort of scale, you need to have databases in transitory states where the application can continue to function even though the underlying database has changed. The quintessential example is adding a column. If you want to deploy with zero downtime, you have to square with the reality that a database schema change and deployment of application code is not an atomic operation. One must happen before the other. Particularly when you deal with fleets of servers with blue/green deploys where server 1 gets deployed at t=0minutes but server N doesn't get deployed until t=60minutes. Your application code will straight up fail if it tries to insert a column that doesn't exist, so it's necessary to change the database first. This normally means adding a column that's either nullable or has a default value, to allow the application to function as normal, without knowing the column exists. So in a way, yes, the application is still the authority, but it's an authority on the interface it expects from the database. It can define which columns should exist, but not which columns should not exist.