This is an Erlang couchdb view for getting all the documents that meet the "namespace/id" criteria, emiting the namespace as document type.

all_view.erl

% Document design: {"_id": "namespace/edf42", ...}
fun({Doc}) ->
  Id = proplists:get_value(<<"_id">>, Doc, null),
  NameSpace = binary:bin_to_list(Id),
  case re:split(NameSpace, "[/]") of
    [_] -> null;
    [Type, BaseId] -> Emit(Type, BaseId)
  end
end.