anchor.diff:  
   
   latest(Period, Node, Bucket, N) when is_atom(Node), is_list(Bucket) ->
  -    walk(table(Node, Bucket, Period), N);
  +    try walk(table(Node, Bucket, Period), N) of
  +        Result -> {ok, Result}
  +    catch
  +        Type:Err -> {error, {Type, Err}}
  +    end;
   latest(Period, Nodes, Bucket, N) when is_list(Nodes), is_list(Bucket) ->
       misc:pmap(fun (Node) ->
                         {Node, latest(Period, Node, Bucket, N)}
  
positive.code: 
  %% @doc Get the latest samples for a given interval from the archive
  latest(Period, Node, Bucket) when is_atom(Node) ->
      {atomic, Result} = mnesia:transaction(
                           fun () ->
                                   Tab = table(Node, Bucket, Period),
                                   Key = mnesia:last(Tab),
                                   hd(mnesia:read(Tab, Key))
                           end),
      Result;
  latest(Period, Nodes, Bucket) when is_list(Nodes), is_list(Bucket) ->
      misc:pmap(fun (Node) ->
                        {Node, latest(Period, Node, Bucket)}
  
negative.code:                       {Node, latest(Period, Node, Bucket, Step, N)}
                end, Nodes, length(Nodes));
  latest(Period, Node, Bucket, Step, N) when is_atom(Node) ->
      try resample(table(Node, Bucket, Period), Step, N) of
          Result -> {ok, Result}
      catch
          Type:Err -> {error, {Type, Err}}
      end.
  
  
  latest_all(Period, Bucket) ->
  