Construct the psycopg2 connection instance

        :return: psycopg2.connect instance

def connect(self):
        """ Construct the psycopg2 connection instance

        :return: psycopg2.connect instance
        """

        if self._conn:
            return self._conn

        self._conn = psycopg2.connect(
            self.config,
            cursor_factory=psycopg2.extras.RealDictCursor,
        )

        self._conn.set_session(autocommit=True)
        psycopg2.extras.register_hstore(self._conn)

        return self._conn