我有什么似乎是损坏的索引？
这是正在发生的事情。我有两个表函数，第一个是一组案例，第二个是一组感知日期。这两组具有 1（案例）到 0 或 1（知道日期）的关系。通常我会像这样查询他们；
SELECT c.CaseID, a.AwareDate
FROM Cases(@date) AS c
LEFT JOIN AwareDates(@date) AS a ON c.CaseID = a.CaseID;
问题在于，并非 AwareDates 中匹配的所有行似乎都已加入。如果我添加一个加入提示，他们就会这样做。说;
SELECT c.CaseID, a.AwareDate
FROM Cases(@date) AS c
LEFT MERGE JOIN AwareDates(@date) AS a ON c.CaseID = a.CaseID;
我从查询计划中注意到的是，添加连接提示会在连接之前添加一种 AwareDate 数据，否则该数据不存在。此外，当没有提示时，查询计划器会将连接翻转为 RIGHT OUTER JOIN，当然，在提示存在的地方保留 LEFT JOIN。
我已经完成了以下操作，没有检测到错误；
DBCC UPDATEUSAGE (0) WITH INFO_MESSAGES, COUNT_ROWS;
EXECUTE sp_updatestats 'resample';
DBCC CHECKDB (0) WITH ALL_ERRORMSGS, EXTENDED_LOGICAL_CHECKS;
我被难住了……有什么想法吗？
这是 UDF 定义
ALTER FUNCTION dbo.Cases( @day date ) RETURNS TABLE
WITH SCHEMABINDING
AS RETURN (
SELECT
CaseID -- other 42 columns ommitted
FROM (
SELECT
ROW_NUMBER() OVER (PARTITION BY CaseID ORDER BY UpdateDate DESC, UpdateNumber DESC) AS RecordAge,
CaseID,
Action
FROM
dbo.CaseAudit
WHERE
convert(date,UpdateDate) <= @day
) AS History
WHERE
RecordAge = 1 -- only the most current record version
AND isnull(Action,'') != N'DEL' -- only include cases that have not been deleted
)
ALTER FUNCTION dbo.AwareDates( @day date ) RETURNS TABLE
WITH SCHEMABINDING
AS RETURN (
WITH
History AS (
SELECT row_number() OVER (PARTITION BY CaseID, ContactID ORDER BY UpdateDate DESC, UpdateNumber DESC) AS RecordAge,
CaseID, InfoReceived, ReceiveDate, ResetClock, Action
FROM dbo.ContactLogAudit WITH (NOLOCK)
WHERE convert(date,UpdateDate) <= @day
),
Notes AS (
SELECT
CaseID,
convert(date,ReceiveDate,112) AS ReceiveDate,
ResetClock
FROM History
WHERE RecordAge = 1 -- only the most current record version
AND isnull(Action,'') != N'DEL' -- only include notes that have not been deleted
AND InfoReceived = N'Y' -- only include notes that have Info Rec'd checked
AND len(ReceiveDate) = 8 AND isnumeric(ReceiveDate) = 1 AND isdate(ReceiveDate) = 1 -- only include those with a valid aware date
),
Initials AS (
SELECT CaseID, min(ReceiveDate) AS ReceiveDate
FROM Notes
GROUP BY CaseID
),
Resets AS (
SELECT CaseID, max(ReceiveDate) AS ReceiveDate
FROM Notes
WHERE ResetClock = N'Y'
GROUP BY CaseID
)
SELECT
i.CaseID AS CaseID,
i.ReceiveDate AS InitialAwareDate, -- the oldest valid aware date value (must have AE Info Reveived checked and a received date)
coalesce(r.ReceiveDate,i.ReceiveDate) AS AwareDate -- either the newest valid aware date value with the Reset Clock checked, otherwise the initial aware date value
FROM Initials AS i
LEFT JOIN Resets AS r
ON i.CaseID = r.CaseID
);
我进一步发现，如果我删除“WITH (NOLOCK)”表提示，我会得到正确的结果。此外，如果向 AwareDates UTF 添加连接提示，甚至在 Initials 和 Resets 之间的 LEFT JOIN 关系上添加 COLLATE Latin1_General_BIN。
查询计划行数——没有连接提示（损坏）
- 案例{实际：25,891，估计：19,071.9}
- AwareDates { 实际：24,693，估计：1,463.09 }
- 首字母{实际：24,693，估计：1,463.09}
- 休息{实际：985，估计：33.2671}
- AwareDates 匹配连接结果集中的 8,108 个 Cases 行
查询计划行数——带有连接提示（工作）
- 案例{实际：25,891，估计：19,071.9}
- AwareDates { 实际：24,673，估计：1,837.67 }
- 首字母{实际：24,673，估计：1,837.67}
- 休息{实际：982，估计：42.6238}
- AwareDates 匹配连接结果集中的 24,673 个 Cases 行
我进一步缩小了问题的范围。我可以;
SELECT * FROM AwareDate(@date);
和
SELECT * FROM AwareDate(@date) ORDER BY CaseID;
具有不同的行数。