Question

我正在运行一个查询来计算一些数字，它似乎运行得非常慢。这是在MSSQL服务器上。运行查询大约需要22秒，只返回34条记录。问题是我同时运行多个SUM，执行时间加起来。我已经将sql语句简化为我需要的准系统。我如何更快地运行？

SELECT 

  SUM(case when (claims.dateon >= '20161110' AND claims.dateon < '20161117') AND entries.errorCode NOT IN('DP','RB','WP','PE','OV') then entries.refundDue else 0.0 end) as rate1

FROM auditors 

INNER JOIN claims 
   ON claims.auditorID = auditors.auditorID 
  AND claims.status='closed' 
--AND (claims.dateon >= '20161020' AND claims.dateon < '20161117') 
INNER JOIN entries 
   ON claims.rID = entries.rid 
WHERE claims.status = 'closed' 
  AND (claims.dateon >= '20161020' AND claims.dateon < '20161117') 

GROUP BY auditors.auditorID

Answer 1

我会更像这样写这个查询：

SELECT auditor_id,
       sum(case when c.dateon >= '20161110' AND c.dateon < '20161117' AND
                     e.errorCode NOT IN ('DP', 'RB', 'WP', 'PE', 'OV')
                then e.refundDue else 0.0
           end) as rate1
FROM auditors a INNER JOIN
     claims c
     ON c.auditorID = a.auditorID AND c.status ='closed' INNER JOIN
     entries e
     ON c.rID = e.rid
WHERE c.status = 'closed' AND (c.dateon >= '20161020' AND c.dateon < '20161117') 
GROUP BY a.auditorID;

然后我会注意到没有必要加入审计员：

SELECT auditor_id,
       sum(case when c.dateon >= '20161110' AND c.dateon < '20161117' AND
                     e.errorCode NOT IN ('DP', 'RB', 'WP', 'PE', 'OV')
                then e.refundDue else 0.0
           end) as rate1
FROM claims c INNER JOIN
     entries e
     ON c.rID = e.rid
WHERE c.status = 'closed' AND
      (c.dateon >= '20161020' AND c.dateon < '20161117') 
GROUP BY c.auditorID;

然后我建议索引：claims(status, dateon, rId, auditorId)和entries(rid, error_code, refunddue)。

使用带有范围的SUM，嵌套的sql，运行缓慢

1 个答案: