We are building In-memory index extension for postgres. We would capture table inserts, updates, deletes using triggers. During vacuum operation, postgres would give calls to ambulkdelete, amvacuumcleanup (as part of index cleanup). As we handle all updates, deletes using triggers, we don't have to do any index cleanup in ambulkdelete. But, what stats should i return from ambulkdelete and amvacuumcleanup? Is that necessary to return stats from ambulkdelete and amvacuumcleanup ?