如何优化包含多个UNION的多个子查询的MySQL查询

Question

我有一个要优化的查询，但没有取得太大的成功。 我正在尝试使用以下sql查询来计算每日使用情况数据并返回正确的结果，但是我想对此进行优化。 在这里，我正在使用具有多个union。的多个子查询。我有它的工作，但我试图进行优化，使其运行速度更快。

/*  Plan First day usage */

SELECT 
  msisdn,
  plan_id,
  plan_date,    
  plan_start_date, 
  plan_end_date,   
  ROUND(total_usage_mb, 2) AS usage_mb,   
  DATE(plan_start_date) usage_date,
 0 AS starting_balance, ROUND(total_usage_mb, 2) AS closing_balance,   
'start Using' AS usage_status

FROM 
  `usage_info`    
WHERE
   DATE(created) = '2016-02-07'
   AND package_status = 'Plan Using'
   AND DATE(plan_start_date) = '2016-02-06'
   AND ROUND(total_usage_mb, 2)>=0

 UNION

 /* SUBSCRIBER RUNNING PLAN USAGE */

SELECT
   msisdn,
   plan_id,
   plan_date,
   plan_start_date,
   plan_end_date,
   ROUND(mb - bm, 2) AS usage_mb,
   usage_date,bm AS starting_balance, mb AS closing_balance,
  'Continuous Using' AS usage_status
FROM
(
  SELECT
   a.msisdn,
   a.plan_id,
   a.plan_date,
   a.plan_start_date,
   a.plan_end_date,
   a.mb mb,
   b.bm bm,a.name_source,
   b.created AS usage_date
  FROM
   (
    SELECT
     msisdn,
     plan_id,
     plan_date,
     plan_start_date,
     plan_end_date,
     total_usage_mb AS mb,
     name_source,
     created
    FROM
     `usage_info`
    WHERE
     DATE(created) = '2016-02-07'
    AND package_status = 'Plan Using'
   ) a,
   (
    SELECT
     msisdn,
     plan_id,
     plan_date,
     plan_start_date,
     plan_end_date,
     total_usage_mb bm,
     name_source,
     created
    FROM
     `usage_info`
    WHERE
     DATE(created) = '2016-02-06'
    AND package_status = 'Plan Using'
   ) b
  WHERE
   a.msisdn = b.msisdn
  AND a.plan_id = b.plan_id
  AND a.plan_date=b.plan_date
  AND a.plan_start_date=b.plan_start_date
  AND a.plan_end_date=b.plan_end_date
  AND a.name_source=b.name_source
  AND a.mb>=b.bm
 ) c WHERE  ROUND(mb - bm, 2)>=0

 UNION

 /* SUBSCRIBER PLAN LAST DAY USAGE */

SELECT
msisdn,
plan_id,
plan_date,
plan_start_date,
plan_end_date,
ROUND(mb - bm, 2) AS usage_mb,
  usage_date,bm AS starting_balance, mb AS closing_balance,
'End Using' AS usage_status
FROM
(  
  SELECT 
   a.msisdn,
   a.plan_id,
   a.plan_date,
   a.plan_start_date,   
   a.plan_end_date, 
   a.mb mb,
   b.bm bm,a.name_source,
   b.created AS usage_date 
 FROM
   (
    SELECT
     msisdn,
     plan_id,
     plan_date,
     plan_start_date,
     plan_end_date,
     total_usage_mb AS mb,
     name_source,
     created
    FROM
     `usage_info`
    WHERE
     DATE(created) = '2016-02-07'
    AND package_status = 'Plan Used'
   ) a,
   (
    SELECT
     msisdn,
     plan_id,
     plan_date,
     plan_start_date,
     plan_end_date,
     total_usage_mb bm,
     name_source,
     created
    FROM
     `usage_info`
    WHERE
     DATE(created) = '2016-02-06'
    AND package_status = 'Plan Using'
    ) b
  WHERE
   a.msisdn = b.msisdn
  AND a.plan_id = b.plan_id
  AND a.plan_date=b.plan_date
  AND a.plan_start_date=b.plan_start_date
  AND a.plan_end_date=b.plan_end_date
  AND a.name_source=b.name_source
AND a.mb>=b.bm
 ) c WHERE  ROUND(mb - bm, 2)>=0

在下面的链接中找到数据库表架构和一些测试数据

http://faisal-ibrahim.info/usage_info.sql

在这方面的任何帮助表示赞赏。 我对SQL不太了解，因此我不太精通诸如此类的查询。

Answer 1

使用JOIN ... ON ...语法。

但是避免FROM ( SELECT ... ) JOIN ( SELECT ... ) ON ...

将DATE(x) = '2016-02-06'更改为

    x >= '2016-02-06'
AND x <  '2016-02-06' + INTERVAL 1 DAY

添加INDEX(msisdn, package_status, created)和INDEX(package_status, created) 。

可能值得这样做

CREATE TEMPORARY TABLE z 
    SELECT ... GROUP BY DATE(created);