Code review comment for lp:~jtv/launchpad/db-bug-499404

Mainly fine.

I prefer the non-unique index names to have an __idx suffix (avoids some probably non-existant namespace issues).

The ON DELETE CASCADE is an issue. If someone attempts to delete a Branch that has a running job, I suspect we actually want to generate an error (or will things somehow progress just fine despite the branch disappearing part of the way through the process?). There is quite a bit of logic in branch deletion on when branches can be deleted, and the DB constraints serve as a safety net for that. The ON DELETE CASCADE on the job column seems sane.

The DB patch is already using an assigned patch number, so nothing to change there.