Question

请告知如何改善此慢查询。

SELECT response.`reasonid`
FROM response 
    INNER JOIN ACTION ON action.actionid = response.actionid 
WHERE 
    response.respdate BETWEEN 20160305 
    AND 20160905 
    AND 
    (
        (
         response.reasonid = 'Prospect Call' 
         AND response.typeid = '0'
         AND action.typeid = '9'
        ) 
    OR 
        (
         response.typeid = '1000'  
         AND action.typeid = '1'
        )
    )

有索引：

response.actionid / response.reasonid / response.typeid / action.typeid / response.respdate

解释结果：

 table   type   possible_keys                   key           key_len  ref               rows   Extra

ACTION   range  PRIMARY,idx_actiontypeid    idx_actiontypeid    5      \N               310617  Using where; Using index
response ref    idx_respdate2,idx_actionid, idx_actionid        5      ACTION.actionid    1         Using where
            idx_reasonid,idx_resptypeid

Answer 1

尝试此查询将一些索引列添加到连接

SELECT response.`reasonid`
FROM response 
    INNER JOIN ACTION ON action.actionid = response.actionid   and response.typeid in( '1000','0') and action.typeid in('0','1')
WHERE 
    response.respdate BETWEEN 20160305 
    AND 20160905 
    AND 
    (
        (
         response.reasonid = 'Prospect Call' 
         AND response.typeid = '0'
         AND action.typeid = '9'
        ) 
    OR 
        (
         response.typeid = '1000'  
         AND action.typeid = '1'
        )
    )

Answer 2

试试：将表格的大小缩小到只需要使用的内容：

select a.* 
from (
      SELECT response.`reasonid`
      FROM response 
      WHERE response.respdate BETWEEN 20160305 AND 20160905 
      ) a
INNER JOIN ACTION ON action.actionid = a.actionid
WHERE (
     response.reasonid = 'Prospect Call' 
     AND response.typeid = '0'
     AND action.typeid = '9'
    ) 
OR 
    (
     response.typeid = '1000'  
     AND action.typeid = '1'
    )

Answer 3

请尝试在查询中指定日期，因为它们在数据库中：

SELECT response.`reasonid`
FROM response 
    INNER JOIN ACTION ON action.actionid = response.actionid 
WHERE 
    response.respdate BETWEEN "2016-03-05" 
    AND "2016-09-05" 
    AND 
    (
        (
         response.reasonid = 'Prospect Call' 
         AND response.typeid = '0'
         AND action.typeid = '9'
        ) 
    OR 
        (
         response.typeid = '1000'  
         AND action.typeid = '1'
        )
    )

并检查这是否加快了您的查询速度。如果将其写为数值（20160305），则数据库必须在比较之前对每一行进行隐式类型转换，这可能会导致性能降低。

Answer 4

您的查询不应该有单独的索引，而是复合甚至覆盖索引。其他人没有评论我感到惊讶。我为索引提供了以下建议

表索引响应（typeid，respdate，reasoned，actionid）动作（actionid，typeid）

然后我调整了查询以使用UNION而不是OR

gtags

在where子句中使用OR进行慢查询

4 个答案: