private function save()
 {
     $this->config->set_database_tables_optimization_enabled($this->form->get_value('database_tables_optimization_enabled'));
     if (!$this->form->field_is_disabled('database_tables_optimization_day')) {
         $this->config->set_database_tables_optimization_day($this->form->get_value('database_tables_optimization_day')->get_raw_value());
     }
     DatabaseConfig::save();
 }