void Item_func_random_bytes::fix_length_and_dec()
{
  collation.set(&my_charset_bin);
  max_length= MAX_RANDOM_BYTES_BUFFER;
}
void Item_func_random_bytes::fix_length_and_dec()
{
  collation.set(&my_charset_bin);
  max_length= MAX_RANDOM_BYTES_BUFFER;
}