protected function _initialize_schema()
    {
        $this->set_database($this->_database_group);

        $this->_fetch_table();
        $this->_fetch_primary_key();

        if($this->primary_key == null && $this->is_base_model_instance()) {
            return;
        }

        $this->_fields = $this->get_fields();

        $this->_guess_is_soft_deletable();
        $this->_guess_is_blamable();
        $this->_guess_is_timestampable();

    }