為什么此嵌套的SQL代碼這么慢

Question

將ADODB記錄集與SQL Server 2016一起使用-此代碼的運行速度比我執行選擇查詢然后通過遍歷記錄集手動進行聚合的速度要慢得多。.有什么想法嗎？

SELECT SUM(wk1) AS wk1, SUM(wk2) AS wk2, SUM(wk3) AS wk3
    , SUM(recCount) AS recCount, MIN(Segment) AS Segment, Bucket
FROM (
    SELECT *, 1 AS recCount, NTILE(8) OVER (ORDER BY NEWID()) AS Bucket
    FROM [Data]
    WHERE (1 = 1 AND [Area] = 'EAST') AND Segment = 2
    ) AS q
GROUP BY Bucket

Answer 1

似乎已經

NTILE(8) OVER (ORDER BY NEWID()) 

片。 如果我改用

(ROW_NUMBER() OVER (ORDER BY (SELECT NULL)) % 8) + 1

它的運行速度似乎要快得多。