Konuları rastgele çekmek

<?php
    $categories = get_the_category($post->ID);
    $category_ids = array();
foreach($categories as $individual_category) $category_ids[] = $individual_category->term_id;
?>
<?php
         query_posts( array(
            'showposts'                => 4,
            'ignore_sticky_posts'    => true,    
            'order'                    => 'dsc',
            'category__in' => $category_ids,
            'meta_key' => 'post_views_count',
            'orderby' => 'meta_value_num',
            'post__not_in' => array($post->ID)
                )
            );
        ?>
        <?php if (have_posts()) : while ( have_posts() ) : the_post() ?>

'orderby' => 'rand',