anchor.diff:  
   %% Compile a single selection column into a fun that can extract the cell
   %% from the row.
  -% -spec compile_select_col(DDL::#ddl_v1{}, ColumnSpec::any()) ->
  -%         #single_sel_column{}.
  +-spec compile_select_col(DDL::#ddl_v1{}, ColumnSpec::any()) ->
  +        #single_sel_column{}.
   compile_select_col(DDL, {{window_agg_fn, FnName}, [FnArg1]}) ->
       case riak_ql_window_agg_fns:start_state(FnName) of
           stateless ->
  
positive.code: }).
  
  %%
  % -spec select_column_clause_folder(#ddl_v1{}, )
  select_column_clause_folder(DDL, ColX, {TypeSet1, SelClause1}) ->
      #riak_sel_clause_v1{
          initial_state = InitX,
  
negative.code:     {error, 'full table scan not implmented'};
  compile(#ddl_v1{} = DDL, #riak_sql_v1{is_executable = false,
                                        type          = sql} = Q) ->
      {ok, S} = compile_select_clause(DDL, Q),
      compile_where_clause(DDL, Q#riak_sql_v1{'SELECT' = S}).
  
  %% adding the local key here is a bodge
  %% should be a helper fun in the generated DDL module but I couldn't
  