super fast random WordPress tag

gistfile1.php

<?php
/**
 * Return a random post tag from the wp_terms table
 *
 * average 0.4ms on a 3K table
 *
 * @author Michael Scott Hertzberg
 * @return mixed|string
 */
function m_random_tag() {
	global $wpdb;
	return $wpdb->get_var( $wpdb->prepare( 'SELECT name FROM wp_terms JOIN( SELECT CEIL(RAND() * (SELECT MAX(term_id) FROM wp_terms)) AS term_id) AS m USING( term_id );' ) );
}

Afaik there's a 'order' => 'rand' arg by default in get_terms().

benchmark comparison to order rand, my sql statement is a lot quicker

Can you do a fast random post for wordpress, I have been trying for the past 3 hours, but they all take longs on my database (4k records)