Je suis coincé dans une situation où j'ai des millions d'enregistrements et j'ai besoin de connexions différentes pour les mêmes enregistrements. Les conditions de commande comportent également des parties délicates. Si je n'applique aucun tri, ma requête donne des résultats rapides. Mais lors de l’application de la clause d’ordre, il faut trop de temps pour obtenir le résultat.
Sans la clause Order, cela donne 5-6 secondes.
Lors de l'application des conditions de commande, le résultat est de 40-45 secondes
SELECT
forms_values.id,
CASE
WHEN forms_values.appointment_type = 2
AND user_patient_assinged_to_doctor.start_time IS NOT NULL
THEN
CASE
WHEN patient_responded_tags_logs.tag_set_at IS NOT NULL
THEN
CASE
WHEN UNIX_TIMESTAMP(
CONVERT_TZ(
patient_responded_tags_logs.tag_set_at,
"+00:00",
"-06:00"
)
) > UNIX_TIMESTAMP(
CONVERT_TZ(
STR_TO_DATE(
CONCAT(
user_patient_assinged_to_doctor.date,
" ",
user_patient_assinged_to_doctor.start_time
),
"%Y-%m-%d %h:%i %p"
),
"+00:00",
"-06:00"
)
)
THEN UNIX_TIMESTAMP(
CONVERT_TZ(
patient_responded_tags_logs.tag_set_at,
"+00:00",
"-06:00"
)
)
ELSE UNIX_TIMESTAMP(
CONVERT_TZ(
STR_TO_DATE(
CONCAT(
user_patient_assinged_to_doctor.date,
" ",
user_patient_assinged_to_doctor.start_time
),
"%Y-%m-%d %h:%i %p"
),
"+00:00",
"-06:00"
)
)
END
ELSE UNIX_TIMESTAMP(
CONVERT_TZ(
STR_TO_DATE(
CONCAT(
user_patient_assinged_to_doctor.date,
" ",
user_patient_assinged_to_doctor.start_time
),
"%Y-%m-%d %h:%i %p"
),
"+00:00",
"-06:00"
)
)
END
ELSE
CASE
WHEN patient_responded_tags_logs.tag_set_at IS NOT NULL
THEN
CASE
WHEN UNIX_TIMESTAMP(
CONVERT_TZ(
patient_responded_tags_logs.tag_set_at,
"+00:00",
"-06:00"
)
) > UNIX_TIMESTAMP(forms_values.created_at)
THEN UNIX_TIMESTAMP(
CONVERT_TZ(
patient_responded_tags_logs.tag_set_at,
"+00:00",
"-06:00"
)
)
ELSE UNIX_TIMESTAMP(forms_values.created_at)
END
ELSE UNIX_TIMESTAMP(forms_values.created_at)
END
END AS "consultation_date_time_ordering",
CASE
WHEN forms_values.appointment_type = 2
AND user_patient_assinged_to_doctor.start_time IS NOT NULL
THEN UNIX_TIMESTAMP(
CONVERT_TZ(
STR_TO_DATE(
CONCAT(
user_patient_assinged_to_doctor.date,
" ",
user_patient_assinged_to_doctor.start_time
),
"%Y-%m-%d %h:%i %p"
),
"+00:00",
"-06:00"
)
)
ELSE UNIX_TIMESTAMP(forms_values.created_at)
END AS "consultation_date_time" ,
CASE
WHEN forms_values.is_postpone = '1'
OR forms_values.is_completed = '8'
THEN
CASE
WHEN UNIX_TIMESTAMP(
CONVERT_TZ(
STR_TO_DATE(
CONCAT(UTC_DATE(), ' ', UTC_TIME()),
'%Y-%m-%d %h:%i:%s'
),
'+00:00',
'-06:00'
)
) < UNIX_TIMESTAMP(
my_list_postpone.postponed_date
)
THEN 0
ELSE 1
END
ELSE 1
END AS "postponed_consultation_ordering"
FROM
`forms_values`
LEFT JOIN `forms_values_completed_status_details`
ON `forms_values_completed_status_details`.`form_value_id` = `forms_values`.`id`
/*INNER JOIN `users`
ON `users`.`id` = `forms_values`.`patient_id`
LEFT JOIN `users` AS `doctors`
ON `doctors`.`id` = `forms_values`.`doctor_id`*/
LEFT JOIN `user_patient_assinged_to_doctor`
ON `user_patient_assinged_to_doctor`.`form_value_id` = `forms_values`.`id`
INNER JOIN `states_countries`
ON `forms_values`.`state` = `states_countries`.`id`
LEFT JOIN `user_payment_history`
ON `user_payment_history`.`form_value_id` = `forms_values`.`id`
LEFT JOIN `emailed_tags_logs`
ON `emailed_tags_logs`.`form_value_id` = `forms_values`.`id`
AND `emailed_tags_logs`.`id` =
(SELECT
emailed_tags_logs.id
FROM
emailed_tags_logs
WHERE emailed_tags_logs.form_value_id = forms_values.id
AND emailed_tags_logs.id =
(SELECT
emailed_tags_logs1.id AS emtid
FROM
emailed_tags_logs AS emailed_tags_logs1
WHERE emailed_tags_logs1.form_value_id = forms_values.id
ORDER BY emailed_tags_logs1.created_at DESC
LIMIT 1)
AND emailed_tags_logs.status IN (1, 3)
AND emailed_tags_logs.is_pt_responded = "0"
ORDER BY emailed_tags_logs.created_at DESC
LIMIT 1)
LEFT JOIN `my_list_assign_doctor`
ON `my_list_assign_doctor`.`form_value_id` = `forms_values`.`id`
AND `my_list_assign_doctor`.`id` =
(SELECT
my_list_assign_doctor.id
FROM
my_list_assign_doctor
WHERE my_list_assign_doctor.form_value_id = forms_values.id
AND my_list_assign_doctor.status IN (1, 2)
AND my_list_assign_doctor.prior_type = "others"
ORDER BY my_list_assign_doctor.created_at DESC
LIMIT 1)
LEFT JOIN `my_list_assign_doctor` AS `my_list_postpone`
ON `my_list_postpone`.`form_value_id` = `forms_values`.`id`
AND `forms_values`.`is_postpone` IN ('1', '2')
AND `my_list_postpone`.`id` =
(SELECT
my_list_assign_doctor.id
FROM
my_list_assign_doctor
WHERE my_list_assign_doctor.form_value_id = forms_values.id
AND my_list_assign_doctor.prior_type = "postpone"
ORDER BY my_list_assign_doctor.created_at DESC
LIMIT 1)
LEFT JOIN `users` AS `partner`
ON `user_payment_history`.`std_partner_id` = `partner`.`id`
LEFT JOIN `patient_responded_tags_logs`
ON `patient_responded_tags_logs`.`form_value_id` = `forms_values`.`id`
AND `patient_responded_tags_logs`.`status` = '1'
LEFT JOIN `user_subscriptions`
ON `user_subscriptions`.`user_payment_history_id` = `user_payment_history`.`id`
AND `user_payment_history`.`form_value_id` = `forms_values`.`id`
ORDER BY
postponed_consultation_ordering DESC,
`consultation_date_time` DESC
LIMIT 10 OFFSET 0
Remarque : toutes les jointures sont importantes, les champs ont été supprimés de la requête de sélection pour certaines considérations.
Résumé explicatif
![[Web front-end] Démarrage rapide de Node.js](https://img.php.cn/upload/course/000/000/067/662b5d34ba7c0227.png)
Le problème est la combinaison de LIMIT et ORDER BY.
Sans ORDER BY, la requête s'arrête une fois les dix premières lignes aléatoires sélectionnées. La requête order by doit collecter toutes les lignes possibles, les trier dans l'ordre, puis renvoyer uniquement les 10 premières lignes.
Considérant que "postponed_consultation_datetime" est un champ calculé, il n'y a vraiment aucun moyen de le rendre plus rapide.