性能调整-MySQL

Question

Is there any scope of tuning below query and increase the performance

SELECT
    i.store_id,
    i.film_id,
    COUNT(*) AS total,
    COUNT(*) - (
        SELECT COUNT(*)
        FROM rental 
        WHERE
            inventory_id IN (SELECT inventory_id FROM inventory
                             WHERE inventory.film_id = i.film_id AND
                                   inventory.store_id = i.store_id)
    ) 
FROM `inventory` i 
GROUP BY
    i.store_id,
    i.film_id

Here I am fetching details on how many are there in store and how may rented out .

Answer 1

In my experience, subselects perform poorly in MySQL. Temporary tables may be a better solution.

Answer 2

Turn IN ( SELECT ... ) into a JOIN.

Add INDEX(store_id, film_id, inventory_id)