We had started a project with PostgreSQL 10.x but during the same time PostgreSQL 11 was released so we decided to go to production with the latest version itself. I was just evaluating the migration from Hibernate 5.3 to 5.4 (I mean that's what CR releases are for, right ?)

I must admit that I'm a bit torn between "it used to work so it should probably continue to work" and "it's hard to support all cases when people change the schema under the hood".

I am not expecting that it should continue to work because it used to work. It was just for information in case it was needed.

Given your response, are you considering to support Hibernate generated schemas only and not user generated ones ? If yes, then I have one additional task and I am fine with it as long as it is documented, as a breaking change, in migration guide for Hibernate version 5.4. If not, then I think this issue should be fixed whenever PostgreSQL 11 support is added to Hibernate.