static function getObjectIdsInNodeSubTree($node)
    {
        $db = eZDB::instance();
        $nodePath =  $node->attribute( 'path_string' );
        $pathString = " path_string like '$nodePath%' AND ";

        $objectIDArray = $db->arrayQuery( "SELECT
                                           ezcontentobject.id
                                    FROM
                                           ezcontentobject_tree, ezcontentobject
                                    WHERE
                                          $pathString
                                          ezcontentobject_tree.contentobject_id=ezcontentobject.id AND
                                          ezcontentobject_tree.main_node_id=ezcontentobject_tree.node_id" );

        if ( count( $objectIDArray ) == 0 )
            return null;

        $objectSimpleIDArray = array();

        foreach ( $objectIDArray as $objectID )
        {
            $objectSimpleIDArray[] = $objectID['id'];
        }

        return $objectSimpleIDArray;
    }