DECLARE
  l_size_b      NUMBER;
  l_size_a      NUMBER;
  l_size_tmp_b  NUMBER;
  l_size_tmp_a  NUMBER;
  l_size_free_b NUMBER;
  l_size_free_a NUMBER;
BEGIN
  SELECT SUM(f.BYTES / 1024 / 1024) INTO l_size_b FROM dba_data_files f;
  SELECT SUM(f.BYTES / 1024 / 1024)
    INTO l_size_free_b
    FROM dba_free_space f;
  SELECT SUM(f.BYTES / 1024 / 1024)
    INTO l_size_tmp_b
    FROM dba_temp_files f;

  --------
   data_load();
  --------  
  SELECT SUM(f.BYTES / 1024 / 1024) INTO l_size_a FROM dba_data_files f;
  SELECT SUM(f.BYTES / 1024 / 1024)
    INTO l_size_free_a
    FROM dba_free_space f;
  SELECT SUM(f.BYTES / 1024 / 1024)
    INTO l_size_tmp_a
    FROM dba_temp_files f;
  dbms_output.put_line('data size ' ||l_size_a|| ' => ' || l_size_b);
  dbms_output.put_line('tmp data size ' ||l_size_tmp_a|| ' => ' || l_size_tmp_b);
  dbms_output.put_line('free data size ' ||l_size_free_a|| ' => ' || l_size_free_b);  
END;