如何在大型数据库中优化具有多个左连接的选择查询

Question

我的查询是

    select  cp_emp_personal_detail.id
           ,cp_emp_personal_detail.emp_code
           ,cp_emp_personal_detail.emp_name
           ,cp_department.department
           ,GROUP_CONCAT(TIME(devicelogs_3_2018.LogDate) ORDER BY devicelogs_3_2018.LogDate) present
    from    cp_emp_personal_detail
    left join cp_emp_official_detail on cp_emp_official_detail.emp_id = cp_emp_personal_detail.id
    left join devicelogs_3_2018 on devicelogs_3_2018.DeviceId = cp_emp_personal_detail.org_id and cp_emp_personal_detail.id AND date(devicelogs_3_2018.LogDate) = CURRENT_DATE()
    left join cp_department on cp_emp_official_detail.department = cp_department.id
    where cp_emp_personal_detail.org_id = 1
    group by cp_emp_personal_detail.id

和数据库设计是

    CREATE TABLE `cp_emp_personal_detail` (
      `id` int(11) NOT NULL,
      `org_id` int(11) NOT NULL,
      `emp_code` varchar(100) DEFAULT NULL,
      `emp_name` varchar(100) NOT NULL,
      `emp_guardian_name` varchar(100) DEFAULT NULL,
      `emp_dob` date NOT NULL,
      `emp_email` varchar(100) DEFAULT NULL,
      `emp_password` varchar(100) NOT NULL,
      `emp_phone` bigint(15) DEFAULT NULL,
      `emp_mobile` bigint(15) NOT NULL,
      `emp_emergency_no` int(11) DEFAULT NULL,
      `emp_address1` longtext NOT NULL,
      `emp_address2` longtext,
      `emp_city` int(11) NOT NULL,
      `emp_pan` varchar(30) NOT NULL,
      `emp_country` int(11) NOT NULL,
      `emp_state` int(11) NOT NULL,
      `emp_aadhar` varchar(30) DEFAULT NULL,
      `emp_tax_status` varchar(100) NOT NULL,
      `emp_pic` varchar(255) DEFAULT NULL,
      `emp_gender` varchar(50) NOT NULL,
      `emp_status` varchar(100) NOT NULL DEFAULT 'activate',
      `crm_status` varchar(11) DEFAULT NULL,
      `created_at` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
      `last_updated_at` timestamp NULL DEFAULT NULL ON UPDATE CURRENT_TIMESTAMP
    ) ENGINE=InnoDB DEFAULT CHARSET=latin1
    PARTITION BY LIST (org_id)
    (
    PARTITION P1 VALUES IN (1) ENGINE=InnoDB,
    PARTITION P2 VALUES IN (2) ENGINE=InnoDB
    );

    CREATE TABLE `devicelogs_3_2018` (
      `DeviceLogId` bigint(20) NOT NULL,
      `DownloadDate` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
      `DeviceId` bigint(20) NOT NULL,
      `UserId` varchar(50) NOT NULL,
      `LogDate` timestamp NOT NULL DEFAULT '1970-12-31 18:30:01',
      `Direction` varchar(255) DEFAULT NULL,
      `AttDirection` varchar(255) DEFAULT NULL,
      `C1` varchar(255) DEFAULT NULL,
      `C2` varchar(255) DEFAULT NULL,
      `C3` varchar(255) DEFAULT NULL,
      `C4` varchar(255) DEFAULT NULL,
      `C5` varchar(255) DEFAULT NULL,
      `C6` varchar(255) DEFAULT NULL,
      `C7` varchar(255) DEFAULT NULL,
      `WorkCode` varchar(255) DEFAULT NULL,
      `hrapp_syncstatus` tinyint(4) DEFAULT NULL
    ) ENGINE=InnoDB DEFAULT CHARSET=latin1;

    CREATE TABLE `cp_department` (
      `id` int(11) NOT NULL,
      `org_id` int(11) NOT NULL,
      `department` varchar(20) NOT NULL,
      `depart_abb` varchar(10) DEFAULT NULL,
      `created_at` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
      `last_updated_at` timestamp NULL DEFAULT NULL ON UPDATE CURRENT_TIMESTAMP
    ) ENGINE=InnoDB DEFAULT CHARSET=latin1
    PARTITION BY LIST (org_id)
    (
    PARTITION P1 VALUES IN (1) ENGINE=InnoDB,
    PARTITION P2 VALUES IN (2) ENGINE=InnoDB
    );

    CREATE TABLE `cp_emp_official_detail` (
      `id` int(11) NOT NULL,
      `emp_id` int(11) NOT NULL,
      `org_id` int(11) NOT NULL,
      `joining_date` date DEFAULT NULL,
      `confirmation_periode` int(11) DEFAULT NULL,
      `job_type` varchar(100) DEFAULT NULL,
      `payment_mode` varchar(100) DEFAULT NULL,
      `department` int(11) DEFAULT NULL,
      `acc_no` int(11) DEFAULT NULL,
      `designation` int(11) DEFAULT NULL,
      `ess_status` int(11) DEFAULT NULL,
      `created_at` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
      `last_updated_at` timestamp NULL DEFAULT NULL ON UPDATE CURRENT_TIMESTAMP
    ) ENGINE=InnoDB DEFAULT CHARSET=latin1
    PARTITION BY LIST (org_id)
    (
    PARTITION P1 VALUES IN (1) ENGINE=InnoDB,
    PARTITION P2 VALUES IN (2) ENGINE=InnoDB
    );

有人可以解释我如何优化查询目前需要3到4分钟来执行超过8k的记录