where 子句中的 dateadd - 在这种特定情况下如何避免完全扫描？

Question

我有以下查询：

SELECT      u.userId,
            app.applicationId
FROM        app.application                 AS app
INNER JOIN  app.applicant                   AS ap   
            ON ap.applicantId = app.applicantId
INNER JOIN  usr.[user]                      AS u    
            ON u.userId = ap.userId
LEFT JOIN   msg.emailTemplateSent           AS t    
            ON t.toUserId = u.userId 
           AND t.emailTemplateName = 'v4_before_sixWeek_latestFlight_reminder'

WHERE       Convert(Date, GETUTCDATE())  = 
            DATEADD(week,-6,Convert(Date, app.flightDateLatest ))

AND         t.emailEventId IS NULL

ORDER BY    app.applicationId ASC

请再次注意where子句的第一行：

Convert(Date, GETUTCDATE())  = DATEADD(week,-6,Convert(Date, app.flightDateLatest ))

我可以以可以使用我的索引的方式更改此设置吗？索引实际上被使用了，但它是一个完整的扫描。

也可以在这里看到：

这是我的索引定义：

USE [APCore];
CREATE NONCLUSTERED INDEX i_flightDateLatest  
ON [app].[application] ( flightDateLatest  ASC  )  
INCLUDE ( [applicantId] , [applicationId] , [programID])  
WITH (  PAD_INDEX = OFF, 
        FILLFACTOR = 100  , 
        SORT_IN_TEMPDB = OFF , 
        ONLINE = OFF, 
--DROP_EXISTING = ON, 
        IGNORE_DUP_KEY = OFF, 
       STATISTICS_NORECOMPUTE = OFF, 
       DATA_COMPRESSION=PAGE, 
       ALLOW_ROW_LOCKS = ON, 
       ALLOW_PAGE_LOCKS = ON ) 
ON [NONCLUSTERED_INDEXES] 

这是完整的执行计划。

flightDateLatest不幸的是，我无法更改从日期时间调用的列以避免转换

除了创建计算列或更改架构之外，还有其他方法可以避免在这种情况下读取全表\索引扫描吗？

更新：

在接受答案后，相应地更改了查询，现在索引用于查找操作，如下图所示。

请注意原始查询成本的 94% 是改进后查询的 6%：

Answer 1

您可以在 getutc 中添加 6 周...
然后测试该特定日期 (flightDateLatest) 是否大于或等于DATEADD(week,6,Convert(Date, GETUTCDATE()))
或小于第二天DATEADD(DAY,1,DATEADD(week,6,Convert(Date, GETUTCDATE())))

SELECT
*
FROM
(
    SELECT CAST('20220511 15:14:52.050' AS DATETIME) as flightDateLatest union all
    SELECT CAST('20220512' AS DATETIME) 
) as app
WHERE   
    app.flightDateLatest >= DATEADD(week,6,Convert(Date, GETUTCDATE()))
    AND 
    app.flightDateLatest < DATEADD(DAY,1,DATEADD(week,6,Convert(Date, GETUTCDATE())))

与输出：

flightDateLatest
2022-05-11 15:14:52.050