MySQL - Slow Несколько подзапросов и GROUP BY

Question

При выполнении следующего запроса с использованием GROUP BY это занимает слишком много времени.

SELECT specialities.id AS ID_DEPARTMENT, 
     specialities.name AS ID_DEPARTMENT_NAME, 
     agenda.idagenda AS ID_SERVICE, 
     agenda.name AS ID_SERVICE_NAME, 
     supervisor.clients_waiting AS CWaiting, 
     IFNULL(supervisor.clients_resent_waiting_area, 0) AS CWaiting_Resent_Area, 
     supervisor.clients_attending AS CAttending, 
     supervisor.clients_attended AS CAttended, 
     (SELECT SUM(TIME_TO_SEC(TIMEDIFF(NOW(), time_waiting))/CWaiting) 
     FROM supervisor_time_data 
     WHERE supervisor_time_data.id_service = supervisor.id_service) AS TME, 
     (SELECT SUM(TIME_TO_SEC(TIMEDIFF(NOW(), time_attending))/CAttending) 
     FROM supervisor_time_data 
     WHERE supervisor_time_data.id_service = supervisor.id_service) AS TMA, 
     (SELECT TIME_TO_SEC(MAX(TIMEDIFF(NOW(), time_waiting))) 
     FROM supervisor_time_data 
     WHERE supervisor_time_data.id_service = supervisor.id_service) AS MTE, 
     (SELECT TIME_TO_SEC(MAX(TIMEDIFF(NOW(), time_attending))) 
     FROM supervisor_time_data 
     WHERE supervisor_time_data.id_service = supervisor.id_service) AS MTA, 
     supervisor.tme_accumulated AS TME_ACCUMULATED, 
     supervisor.tma_accumulated AS TMA_ACCUMULATED 
FROM supervisor, supervisor_time_data, agenda, specialities 
WHERE supervisor.id_service = agenda.id 
    AND supervisor_time_data.id_service = supervisor.id_service 
    AND agenda.idspeciality = specialities.id 
    AND supervisor.booked_or_sequential = 0 
    AND supervisor.id_service IN (1,2,3) 
GROUP BY supervisor.id_service 
ORDER BY agenda.name ASC; 

Это занимает более 3 секунд при комментировании строки GROUP BY, она занимает 8 мс.

Любые идеи о том, как я могу оптимизировать этот запрос?

Благодаря

EDIT:

CREATE TABLE `supervisor` (
    `id` int(9) NOT NULL AUTO_INCREMENT, 
    `id_department` int(6) DEFAULT NULL, 
    `id_service` int(9) DEFAULT NULL, 
    `clients_waiting` int(6) DEFAULT '0', 
    `clients_attending` int(6) DEFAULT '0', 
    `clients_attended` int(6) DEFAULT '0', 
    `tma_accumulated` int(9) DEFAULT '0', 
    `tme_accumulated` int(9) DEFAULT '0', 
    `clients_resent_waiting_area` int(6) DEFAULT NULL, 
    `booked_or_sequential` tinyint(1) DEFAULT NULL, 
    PRIMARY KEY (`id`), 
    KEY `id_service` (`id_service`), 
    KEY `booked_or_sequential` (`booked_or_sequential`), 
    KEY `clients_waiting` (`clients_waiting`) 
) ENGINE=MyISAM AUTO_INCREMENT=172 DEFAULT CHARSET=latin1; 

.

CREATE TABLE `supervisor_time_data` (
    `id` int(9) NOT NULL AUTO_INCREMENT, 
    `id_ogs` int(32) DEFAULT NULL, 
    `booked_or_sequential` tinyint(1) DEFAULT NULL, 
    `time_waiting` datetime DEFAULT NULL, 
    `time_attending` datetime DEFAULT NULL, 
    `status` int(2) DEFAULT '0', 
    `id_service` int(6) DEFAULT NULL, 
    PRIMARY KEY (`id`), 
    KEY `id_service` (`id_service`), 
    KEY `time_waiting` (`time_waiting`), 
    KEY `time_attending` (`time_attending`), 
    KEY `booked_or_sequential` (`booked_or_sequential`) 
) ENGINE=MyISAM AUTO_INCREMENT=2281 DEFAULT CHARSET=latin1; 

.

CREATE TABLE `agenda` (
    `id` int(3) NOT NULL AUTO_INCREMENT, 
    `name` varchar(255) DEFAULT NULL, 
    `idagenda` varchar(255) DEFAULT NULL, 
    `iduser` int(3) DEFAULT NULL, 
    `date_created` datetime DEFAULT NULL, 
    `agendatype` tinyint(4) DEFAULT NULL, 
    `idspeciality` int(6) DEFAULT NULL, 
    `denomination` varchar(255) DEFAULT NULL, 
    `ticket_count` int(3) DEFAULT NULL, 
    `waiting` int(3) DEFAULT NULL, 
    `ticket_start` int(3) DEFAULT NULL, 
    `ticket_end` int(3) DEFAULT NULL, 
    `ticket_letter` varchar(12) DEFAULT NULL, 
    `idcenter` int(9) DEFAULT NULL, 
    PRIMARY KEY (`id`), 
    KEY `idagenda` (`idagenda`), 
    KEY `idspeciality` (`idspeciality`) 
) ENGINE=MyISAM AUTO_INCREMENT=2228 DEFAULT CHARSET=latin1; 

.

CREATE TABLE `specialities` (
    `id` int(6) NOT NULL AUTO_INCREMENT, 
    `name` varchar(255) DEFAULT NULL, 
    `date_created` datetime DEFAULT NULL, 
    `idwaitingarea` int(3) DEFAULT NULL, 
    PRIMARY KEY (`id`) 
) ENGINE=MyISAM AUTO_INCREMENT=149 DEFAULT CHARSET=latin1; 

Answer 1

Вот ваши вопросы с присоединениями. Отправьте свою схему, если это не сработает.

SELECT 
    specialities.id    AS ID_DEPARTMENT, 
    specialities.name   AS ID_DEPARTMENT_NAME, 
    agenda.idagenda    AS ID_SERVICE, 
    agenda.name     AS ID_SERVICE_NAME, 
    supervisor.clients_waiting AS CWaiting, 
    IFNULL(supervisor.clients_resent_waiting_area, 0) AS CWaiting_Resent_Area, 
    supervisor.clients_attending AS CAttending, 
    supervisor.clients_attended AS CAttended, 
    SUM(TIME_TO_SEC(TIMEDIFF(NOW(), supervisor_time_data.time_waiting))/supervisor.clients_waiting) AS TME, 
    SUM(TIME_TO_SEC(TIMEDIFF(NOW(), supervisor_time_data.time_attending))/supervisor.clients_attending) AS TMA, 
    TIME_TO_SEC(MAX(TIMEDIFF(NOW(), supervisor_time_data.time_waiting))) AS MTE, 
    TIME_TO_SEC(MAX(TIMEDIFF(NOW(), supervisor_time_data.time_attending))) AS MTA, 
    supervisor.tme_accumulated AS TME_ACCUMULATED, 
    supervisor.tma_accumulated AS TMA_ACCUMULATED 
FROM supervisor 
    LEFT JOIN supervisor_time_data 
    ON supervisor_time_data.id_service = supervisor.id_service 
    LEFT JOIN agenda 
    ON supervisor.id_service = agenda.id 
    LEFT JOIN specialities 
    ON agenda.idspeciality = specialities.id 
WHERE supervisor.booked_or_sequential = 0 
    AND supervisor.id_service IN(1,2,3) 
GROUP BY supervisor.id_service 
ORDER BY agenda.name ASC;