There's also some DB updates that, even if strictly speaking non-backwards compatible, run in just a matter of seconds. Additionally, in postgres you can set st

There's also some DB updates that, even if strictly speaking non-backwards compatible, run in just a matter of seconds. Additionally, in postgres you can set statement_timeout, which should abort any query that takes too long. If you have a reasonable deployment strategy, then the chance that someone will talk to your application in the exact moment that the app is in some invalid state, might be quite small.