On 2019-12-10 08:55, Dan shmidt wrote:
> What is the correct way to perform such an operation?
> Is there a way to keep constraint #1 or the only option is to not allow
> "breaking" schema changes between versions.
It all depends on the specific schema changes you want to make. You can
add columns on the subscriber and remove columns on the publisher
without breaking things (unless there are not-null constraints).
Renaming columns will break replication until you rename them
everywhere. Column type changes will usually just work as long as the
data fits into both the old and the new type.
You really need to carefully plan and test each class of scenarios
separately.
--
Peter Eisentraut
http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services