function article($link){

print_story($link->id);

print_comment(0,$link->id);

}

function print_comment($parent_id, $link_id){

$comments = $db->get_col("SELECT comment_id FROM table_comments WHERE comment_link_id=$link_id and comment_parent = $parent_id ORDER BY comment_votes DESC");

if ($comments) {

		$comment = new Comment;
		foreach($comments as $comment) {		
				$comment->print();
			}
				print_comment($comment_id,$link_id);
		}
								
	}

TABLE `table_comments` (

  `comment_id`, `comment_parent`, `comment_link_id`, `comment_votes`

If you store and manipulate all the data in memory, I don't see why this would be that bad?