Thanks for the reply. We have a similar architecture where I work so this is interesting to me. A couple more questions if you don't mind:

- Do you use any tools for orchestrating the rollout of those schema changes or do you just have some homegrown scripts?

- Do you separate your schema versioning and deployment process from your application versioning and deployment process?

- How do you handle cases where backwards-compatibility is not possible? For example, a new application feature that depends on a brand new table.