SQL Server Execpt和not in 性能区别

CREATE TABLE tb1(ID int) 



CREATE TABLE tb2(ID int)



BEGIN  TRAN

DECLARE @i INT = 500

WHILE @i > 0

begin

INSERT INTO dbo.tb1

VALUES  ( @i  -- v - int

          )

SET @i = @i -1

end

COMMIT

我测试的时候tb1 是1000，tb2 是500

 DBCC FREESYSTEMCACHE ('ALL','default');



SET STATISTICS IO ON

SET STATISTICS TIME on

SELECT * FROM tb1 EXCEPT SELECT * FROM tb2;

SELECT * FROM tb1 WHERE id NOT IN(SELECT id FROM tb2);--得不到任何值

 SET STATISTICS IO OFF

SET STATISTICS TIME OFF

SELECT * FROM tb1 EXCEPT SELECT * FROM tb2;

|--Merge Join(Right Anti Semi Join, MERGE:([master1].[dbo].[tb2].[ID])=([master1].[dbo].[tb1].[ID]), RESIDUAL:([master1].[dbo].[tb1].[ID] = [master1].[dbo].[tb2].[ID]))

       |--Sort(DISTINCT ORDER BY:([master1].[dbo].[tb2].[ID] ASC))

       |    |--Table Scan(OBJECT:([master1].[dbo].[tb2]))

       |--Sort(DISTINCT ORDER BY:([master1].[dbo].[tb1].[ID] ASC))

            |--Table Scan(OBJECT:([master1].[dbo].[tb1]))

SELECT * FROM tb1 WHERE id NOT IN(SELECT id FROM tb2);--得不到任何值

  |--Hash Match(Right Anti Semi Join, HASH:([master1].[dbo].[tb2].[ID])=([master1].[dbo].[tb1].[ID]), RESIDUAL:([master1].[dbo].[tb1].[ID]=[master1].[dbo].[tb2].[ID]))

       |--Table Scan(OBJECT:([master1].[dbo].[tb2]))

       |--Nested Loops(Left Anti Semi Join)

            |--Nested Loops(Left Anti Semi Join, WHERE:([master1].[dbo].[tb1].[ID] IS NULL))

            |    |--Table Scan(OBJECT:([master1].[dbo].[tb1]))

            |    |--Top(TOP EXPRESSION:((1)))

            |         |--Table Scan(OBJECT:([master1].[dbo].[tb2]))

            |--Row Count Spool

                 |--Table Scan(OBJECT:([master1].[dbo].[tb2]), WHERE:([master1].[dbo].[tb2].[ID] IS NULL))