public function destroy( $sessionId )
    {
        ezpEvent::getInstance()->notify( 'session/destroy', array( $sessionId ) );

        $db = eZDB::instance();
        $escKey = $db->escapeString( $sessionId );

        eZSession::triggerCallback( 'destroy_pre', array( $db, $sessionId, $escKey ) );
        $db->query( "DELETE FROM ezsession WHERE session_key='$escKey'" );
        eZSession::triggerCallback( 'destroy_post', array( $db, $sessionId, $escKey ) );

        return true;
    }