sql count不要和查询数据混用 非常耗时

Posted 2020-10-15 Lulus

count(1)不要和查询数据混用 非常耗时

例子：

SELECT  w.[PKID],
        COUNT(1) OVER() AS TotalCount
FROM w  WITH(NOLOCK)
INNER JOIN  s WITH(NOLOCK)
    ON s.PKID= w.SID
INNER JOIN s2 WITH (NOLOCK)
    ON s2.PKID= w.SID2
INNER JOIN w2 AS WTLWITH(NOLOCK)
    ON W2.WID=w.PKID
ORDER BY w.PKID 
OFFSET 0 ROW FETCH NEXT 15 ROW ONLY