SQL Server 2008 R2 存储过程很慢

Question

我要加入 3 个不同的表格以实现自动完成功能，而且它必须很快。建议必须及时返回。我需要使用 LIKE 运算符查看 3 个不同的字段以获得答案。请参阅下面的详细信息。

DECLARE @Space AS CHAR(1) = ' ';

 SELECT TOP (@QuantityToReturn) * 
 FROM
     (SELECT
          C.CMPID, C.CMPNAME, C.CMPTHEIRCODE, AD.ADTOWN
      FROM COMPANY C
      JOIN [dbo].[COMPADDRESS] CA ON CA.CMPID = C.CMPID
      JOIN [dbo].[ADDRESS] ad ON AD.ADID = CA.ADID
      JOIN [dbo].SUPPLIER SUP ON C.CMPID = SUP.CMPID
      WHERE 
          (C.CMPID = @LoggedInUserId
           OR @LoggedInUserId = dbo.fnIsAParentCompanyOf(@LoggedInUserId, C.CMPID) 
           OR @LoggedInUserId = 12345)

      UNION 

      SELECT
          C.CMPID, C.CMPNAME, C.CMP_THEIRCODE, AD.ADTOWN
      FROM COMPANY C
      JOIN [dbo].[COMPADDRESS] CA ON ca.CMPID = C.CMPID
      JOIN [dbo].[ADDRESS] AD ON AD.ADID = CA.ADID
      JOIN [dbo].CUSTOMER CUS ON C.CMPID = CUS.CMPID AND CUS.CUSTISTHIS = 1
      WHERE 
          (C.CMPID = @LoggedInUserId
           OR @LoggedInUserId = dbo.fnIsAParentCompanyOf(@LoggedInUserId, C.CMPID) 
           OR @LoggedInUserId = 12345)
      ) AS Results
      WHERE 
          (CMPNAME + @Space + ADTOWN + @Space + CMPTHEIRCODE) LIKE '%' + @Query + '%'

上面的代码很慢（~9sec）

• 如果我使用：WHERE CMPNAME LIKE '%' + @Query + '%' = 快速；
• 如果我使用：WHERE ADTOWN LIKE '%' + @Query + '%' = 快速；
• 如果我使用：WHERE CMPTHEIRCODE LIKE '%' + @Query + '%' = 快速；

只有当我连接它们时才会变慢？

Answer 1

我会尝试这样：

WHERE 
    LEN(@Query) <> LEN(REPLACE(@Query, CMPNAME, ''))

    AND (LEN(@Query) <> LEN(REPLACE(@Query, ADTOWN, ''))
         AND CHARINDEX(CMPNAME, @Query) = (CHARINDEX(ADTOWN, @Query) - 1 - LEN(CMPNAME)) 
        ) -- making sure that the value of ADTOWN comes after CMPNAME

    AND (LEN(@Query) <> LEN(REPLACE(@Query, CMPTHEIRCODE, ''))
         AND CHARINDEX(ADTOWN, @Query) = (CHARINDEX(CMPTHEIRCODE, @Query) - 1 - LEN(ADTOWN))
        ) -- making sure that the value of CMPTHEIRCODE comes after ADTOWN

我尝试重新实现您的 3 个条件的逻辑，以便在参数上运行，而不是在您拥有索引的列上运行。我的假设是在这种情况下将使用索引。

PS：查找/减去 charindex 的结果时可能需要进行一些小调整，以防我在计算中犯了一些错误，但希望你明白了。 - SQLFiddle to validate that the CHARINDEX() comparisons are correct。

另外，我建议/尝试对查询的顶部进行一些额外的更改，以便最终您的脚本如下所示：

DECLARE @Space AS CHAR(1) = ' ';

SELECT TOP (@QuantityToReturn) *
FROM (
    SELECT C.CMPID
        ,C.CMPNAME
        ,C.CMPTHEIRCODE
        ,AD.ADTOWN
    FROM COMPANY C
    INNER JOIN [dbo].[COMPADDRESS] CA
        ON CA.CMPID = C.CMPID
    INNER JOIN [dbo].[ADDRESS] ad
        ON AD.ADID = CA.ADID
    WHERE (
            C.CMPID = @LoggedInUserId
            OR @LoggedInUserId = dbo.fnIsAParentCompanyOf(@LoggedInUserId, C.CMPID)
            OR @LoggedInUserId = 12345
            )
        AND EXISTS (
            SELECT 1
            FROM [dbo].SUPPLIER SUP
            WHERE C.CMPID = SUP.CMPID
            )

    UNION

    SELECT C.CMPID
        ,C.CMPNAME
        ,C.CMP_THEIRCODE
        ,AD.ADTOWN
    FROM COMPANY C
    INNER JOIN [dbo].[COMPADDRESS] CA
        ON ca.CMPID = C.CMPID
    INNER JOIN [dbo].[ADDRESS] AD
        ON AD.ADID = CA.ADID
    WHERE (
            C.CMPID = @LoggedInUserId
            OR @LoggedInUserId = dbo.fnIsAParentCompanyOf(@LoggedInUserId, C.CMPID)
            OR @LoggedInUserId = 12345
            )
        AND EXISTS (
            SELECT 1
            FROM [dbo].CUSTOMER CUS
            WHERE C.CMPID = CUS.CMPID
                AND CUS.CUSTISTHIS = 1
            )
    ) AS Results
WHERE LEN(@Query) <> LEN(REPLACE(@Query, CMPNAME, ''))
    AND (
        LEN(@Query) <> LEN(REPLACE(@Query, ADTOWN, ''))
        AND CHARINDEX(CMPNAME, @Query) = (CHARINDEX(ADTOWN, @Query) - 1 - LEN(CMPNAME))
        ) -- making sure that the value of ADTOWN comes after CMPNAME
    AND (
        LEN(@Query) <> LEN(REPLACE(@Query, CMPTHEIRCODE, ''))
        AND CHARINDEX(ADTOWN, @Query) = (CHARINDEX(CMPTHEIRCODE, @Query) - 1 - LEN(ADTOWN))
        ) -- making sure that the value of CMPTHEIRCODE comes after ADTOWN

希望对你有帮助。