下面的SQL
SELECT TOP 1 WITH TIES b.IId ,b.LId
FROM [test].[dbo].[IEL] b
WHERE b.IType =10
AND b.EId != 'SSDD'
ORDER BY ROW_NUMBER() OVER(PARTITION BY b.IId ORDER BY b.LUpdate DESC)
通过IO 发现,原来的
Scan count 9, logical reads 1772
增加了一个索引
create index idx_ite on [test].[dbo].[IEL](IType ,EId ) include( IId ,LId ,LUpdate )
Scan count 17, logical reads 177
逻辑读大量减少,但是scan count 增加了, 这是成功还是失败?
------解决方案--------------------
好像曾经看过,现在一时半刻不知道哪里找回来了,偶发性的东西不用太过在意,我个人觉得这种情况应该是发生了阻塞或者重编译