1.

EXPLAIN SELECT last_name, first_name, ROUND(AVG(length), 0) AS average FROM actor INNER JOIN film_actor ON film_actor.actor_id = actor.actor_id INNER JOIN film ON film_actor.film_id = film.film_id WHERE title = "ALONE TRIP" GROUP BY last_name, first_name ORDER BY average;

2.

EXPLAIN SELECT last_name, first_name, ROUND(AVG(length), 0) AS average

FROM actor

INNER JOIN film_actor ON film_actor.actor_id = actor.actor_id

INNER JOIN film ON film_actor.film_id = film.film_id

WHERE title

GROUP BY last_name, first_name

ORDER BY average;

EXPLAIN SELECT last_name, first_name, ROUND(AVG(length), 0) AS average FROM actor INNER JOIN film_actor ON film_actor.actor_id = actor.actor_id INNER JOIN film ON film_actor.film_id = film.film_id WHERE title

3.

EXPLAIN SELECT last_name, first_name, ROUND(AVG(length), 0) AS average FROM actor INNER JOIN film_actor ON film_actor.actor_id = actor.actor_id INNER JOIN film ON film_actor.film_id = film.film_id WHERE title > "ALONE TRIP" GROUP BY last_name, first_name ORDER BY average;

1:Text EXPLAIN result on data set with 30 films