But it looks like then inserting a relationship with expiration still leaves the same identical relationship without expiration existing right? Then I would still need to go and find and delete all of the relationships without expiration before I can migrate again to the schema containing only relationships with expiration? I kind of thought that the new relationship with expiration has the same "key" as the old one so it would just update that one. If not then that's also fine, we can at least get the expiration up and running for current and future things and then go and slowly delete relationships without expiration