In case you have your own slow SQL query, you can optimize it automatically here.
For the query above, the following recommendations will be helpful as part of the SQL tuning process.
You'll find 3 sections below:
ALTER TABLE `customer` ADD INDEX `customer_idx_customer_id` (`customer_id`); ALTER TABLE `payment` ADD INDEX `payment_idx_customer_id` (`customer_id`);
SELECT c.customer_id, c.first_name, SUM(p.amount) total, COUNT(p.amount) n_payments FROM customer c INNER JOIN payment p ON c.customer_id = p.customer_id GROUP BY c.customer_id ORDER BY n_payments DESC