[progval]

> immutable URL key like issue/pr

they are not immutable because repositories can change URLs (renamed or moved to a different org).

[bob1029]

Issue #, commit hashes, etc. are still immutable in this scenario. When you rename or transfer a GitHub repository, all of these keys are preserved.

What I do is store 2 tuples:

Repository: (Id, Org, Repo)

Issue/PR: (Repository.Id, #)

Transferring or renaming a repository is an update to 1 row in this schema.