SQL server替代品或处于where条件

或的替代方案是什么？该或正在进行此查询 真慢

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您可以尝试删除

distinct

，并确保在

tbl\u响应（ClientRequestId）

上有索引：

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其他索引可能会有所帮助。此外，卸下外部的

独立的
（如果不需要也会提高性能）。其他索引可能会有所帮助，但无法指定，因为您没有限定
AreCalculationsCompleted
经常将
或
重写为
UNION
帮助

SELECT DISTINCT c.ID
FROM tbl_Case c INNER JOIN
     tbl_RequestBaseRequest b
     ON CaseId = c.ID
WHERE AreCalculationsCompleted = 0 AND
      b.IsApplicantRequest = 1 and
      c.IsArchived = 0 AND
      (b.ID IN (SELECT ClientRequestId FROM tbl_Response) OR
       b.OldClientRequestId IN (SELECT ClientRequestId FROM tbl_Response)
      );

SELECT DISTINCT c.ID 
FROM tbl_Case c 
INNER JOIN tbl_RequestBaseRequest b ON CaseId = c.ID
INNER JOIN tbl_Response r ON (b.ID = r.ClientRequestId OR b.OldClientRequestId = r.ClientRequestId)

您可以将c和b的连接封装到CTE中，并在联合的两个分支中引用它，而不是重复它，或者如果初始连接本身很昂贵，则将其具体化到临时表中，从而在某种程度上对其进行整理。
您将两次运行同一子查询。在这种情况下，您可以将关键字
与
一起使用，以便只需运行一次。与答案中的方法相比，这可能是一种更好的方法，也可能不是。
SELECT c.ID
FROM   tbl_Case c
       INNER JOIN tbl_RequestBaseRequest b
               ON CaseId = c.ID
WHERE  AreCalculationsCompleted = 0
       AND b.IsApplicantRequest = 1
       AND c.IsArchived = 0
       AND b.ID IN (SELECT ClientRequestId
                    FROM   tbl_Response)
UNION
SELECT c.ID
FROM   tbl_Case c
       INNER JOIN tbl_RequestBaseRequest b
               ON CaseId = c.ID
WHERE  AreCalculationsCompleted = 0
       AND b.IsApplicantRequest = 1
       AND c.IsArchived = 0
       AND b.OldClientRequestId IN (SELECT ClientRequestId
                                    FROM   tbl_Response) 

SELECT DISTINCT c.id
FROM tbl_Case c
JOIN tbl_RequestBaseRequest b ON CaseId = c.id
WHERE AreCalculationsCompleted = 0
    AND b.IsApplicantRequest = 1
    AND c.IsArchived = 0
    AND EXISTS(
        SELECT *
        FROM tbl_Response r
        WHERE r.ClientRequestId IN (b.id, b.OldClientRequestId)
    )

SELECT DISTINCT c.ID 
FROM tbl_Case c 
INNER JOIN tbl_RequestBaseRequest b ON CaseId = c.ID
INNER JOIN tbl_Response r ON (b.ID = r.ClientRequestId OR b.OldClientRequestId = r.ClientRequestId)

SELECT c.ID
FROM   tbl_Case c
       INNER JOIN tbl_RequestBaseRequest b
               ON CaseId = c.ID
WHERE  AreCalculationsCompleted = 0
       AND b.IsApplicantRequest = 1
       AND c.IsArchived = 0
       AND b.ID IN (SELECT ClientRequestId
                    FROM   tbl_Response)
UNION
SELECT c.ID
FROM   tbl_Case c
       INNER JOIN tbl_RequestBaseRequest b
               ON CaseId = c.ID
WHERE  AreCalculationsCompleted = 0
       AND b.IsApplicantRequest = 1
       AND c.IsArchived = 0
       AND b.OldClientRequestId IN (SELECT ClientRequestId
                                    FROM   tbl_Response) 

SELECT DISTINCT c.ID 
FROM tbl_Case c 
    INNER JOIN tbl_RequestBaseRequest b 
        ON CaseId = c.ID
        AND AreCalculationsCompleted = 0
        AND b.IsApplicantRequest = 1
        AND c.IsArchived=0
        AND EXISTS (SELECT NULL 
                    FROM tbl_Response 
                    WHERE ClientRequestId IN (b.ID, b.OldClientRequestId))