public static function getAll()
    {
        global $wpdb;
        if (false === ($results = get_transient(self::TRANSIENT_ALL_TAGS))) {
            $results = $wpdb->get_results('
				SELECT ta.term_taxonomy_id as taxonomy_id, name, slug, count(*) total
				FROM ' . $wpdb->prefix . 'term_taxonomy ta
				JOIN ' . $wpdb->prefix . 'terms te ON (te.term_id = ta.term_id)
				JOIN ' . $wpdb->prefix . 'term_relationships re ON (re.term_taxonomy_id = ta.term_taxonomy_id)
				WHERE taxonomy = "post_tag"
				GROUP BY name, slug, taxonomy_id
				ORDER BY total DESC, name, slug');
            set_transient(self::TRANSIENT_ALL_TAGS, $results, 12 * HOUR_IN_SECONDS);
        }
        return $results;
    }