anchor.diff:      P1 = [Prefix, <<"handoffs">>, <<"inbound">>],
       P2 = [Prefix, <<"handoffs">>, <<"outbound">>],
       Seen1 = maybe_idx(Prefix, [<<"handoffs">>], P1,
  -                      [{<<>>, <<"direction">>, <<"inbound">>}],
  +                      [{<<"ddb">>, <<"direction">>, <<"inbound">>}],
                        Seen),
       Dict1 = add_to_dict(P1, Time, length(Inbound), Dict),
       Seen2 = maybe_idx(Prefix, [<<"handoffs">>], P2,
  -                      [{<<>>, <<"direction">>, <<"outbound">>}],
  +                      [{<<"ddb">>, <<"direction">>, <<"outbound">>}],
                        Seen1),
       Dict2 = add_to_dict(P2, Time, length(Outbound), Dict1),
       {Seen2, Dict2}.
  
positive.code:         false ->
              dqe_idx:add(?BUCKET, Metric,
                          ?BUCKET, Key,
                          undefined, [{<<>>, <<"host">>, Host} | Tags]),
              sets:add_element(SetKey, Seen);
          true ->
              Seen
  
negative.code:     Metric = metric_name(Name),
      SeenAcc1 = maybe_idx(Prefix, Metric, [Prefix | Metric],
                           [
                            {<<"ddb">>, <<"type">>, <<"count">>}
                           ],
                           SeenAcc),
      DictAcc1 = add_metric(Prefix, Metric,
  