mysql中LIMIT分页如何优化

SELECT film_id,description FROM film ORDER BY title LIMIT 50,5;

    　　如果这张表非常大，那么这个查询最好改成下面的样子：

SELECT film.film_id,film.description

FROM film INNER JOIN (

    SELECT film_id FROM film ORDER BY title LIMIT 50,5

) AS tmp USING(film_id);