anchor.diff:              Bind = hd(Bmatch),     
               case Bind of
                   #bind{type=binterm} ->  
  -                    %% db field encoded as binary, must decode to term
  +                    %% db field encoded as binary, must decode to term in where tree
  +                    %% this conversion is removed for simple column expressions in column_map_lookup
                       #bind{type=term,btree={from_binterm,Bind}};
                   _ ->    
  -                    %% db field is not stored in encoded form
  +                    %% db field is not stored in encoded form, no transformation needed
                       Bind
               end
       end.
  
positive.code:     ?Warn("column_map_columns error Acc ~p~n", [Acc]),
      ?ClientError({"Column map invalid columns",Columns}).
  
  column_map_lookup({Schema,Table,Name}=QN3,FullMap) ->
      % ?LogDebug("column_map lookup ~p ~p ~p~n", [Schema,Table,Name]),
      Pred = fun(__FM) ->
          ((Name == undefined) orelse (Name == __FM#bind.name)) 
  
negative.code:     if 
          (Tcount==0) andalso (Schema == undefined) andalso (Name /= undefined) ->
              %% Maybe we got a table name {undefined,Schema,Table}  
              field_map_lookup({Table,Name,undefined},FullMap);
          (Tcount==0) ->  
              ?ClientError({"Unknown field or table name", qname3_to_binstr(QN3)});
          (Tcount > 1) ->
  