Method exec

sql/sql_window.cc:3060–3092

Compute the value of window function for all rows. */

  Compute the value of window function for all rows.
*/
bool Window_func_runner::exec(THD *thd, TABLE *tbl, SORT_INFO *filesort_result)
{
  List_iterator_fast<Item_window_func> it(window_functions);
  Item_window_func *win_func;
  while ((win_func= it++))
  {
    win_func->set_phase_to_computation();
    // TODO(cvicentiu) Setting the aggregator should probably be done during
    // setup of Window_funcs_sort.
    win_func->window_func()->set_aggregator(thd,
                                            Aggregator::SIMPLE_AGGREGATOR);
  }
  it.rewind();

  List<Cursor_manager> cursor_managers;
  if (get_window_functions_required_cursors(thd, window_functions,
                                            &cursor_managers))
    return true;

  /* Go through the sorted array and compute the window function */
  bool is_error= compute_window_func(thd,
                                     window_functions,
                                     cursor_managers,
                                     tbl, filesort_result);
  while ((win_func= it++))
  {
    win_func->set_phase_to_retrieval();
  }

  cursor_managers.delete_elements();

  return is_error;
}


bool Window_funcs_sort::exec(JOIN *join, bool keep_filesort_result)