Sorry, I only just noticed this thread. I may be missing something, but UUID feels somewhat heavyweight to me for this problem.
I wonder whether strengthening the history-based matching would be sufficient instead. If timelines with the same TLI but different histories can be treated as distinct and pg_rewind continues walking the history chain until it finds a common ancestor, that seems like a fairly natural fit with the existing timeline model. UUIDs would certainly make identification straightforward, although they would also introduce longer identifiers that are a bit less convenient for humans to work with. My initial thought is that it may be worth exploring how far we can get with the existing history information before introducing a new identifier. regards. -- Kyotaro Horiguchi NTT Open Source Software Center
