I have a database which runs in a separate project from my Node app. I want to move the database into the same project as the app, so that they don't have to talk to each other through a proxy.

Moving between projects is not available on Railway, as I read here: https://station.railway.com/questions/migrate-service-or-at-least-volume-fro-f7fc307f

What could be the least painful way to move the database anyway with minimal downtime? For example, doing a pg_dump and then restoring will require some down time to avoid data being out of sync. Is there any other way?