SqlServer 函數Declare通過傳變量查詢超慢解決辦法 2，OPTION(RECOMPILE)提高帶參數執行SQL語句的索引效率

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參考：

1，Declare傳參查詢速度慢，直接放入參數執行sql卻快，求大牛給原因

2，OPTION(RECOMPILE)提高帶參數執行SQL語句的索引效率

 

遇到的問題：通過參數執行sql函數查詢速度超慢

示例示例代碼：

class="lang:tsql decode:true">declare @prefix nvarchar(10) = '095-0021-' ;
declare @serialLength int  = 4  ;
declare @remainedLength int = 1;

--1，直接傳值，速度很快 
select * from  [dbo].[f_getPartSerialNo]('095-0021-',4,1)
--2，傳變量，速度超慢
select * from  [dbo].[f_getPartSerialNo]( @prefix , @serialLength  , @remainedLength  )
--3，使用OPTION(RECOMPILE)解決2速度慢問題。執行速度同1
select  * from dbo.[f_getPartSerialNo]( @prefix , @serialLength  , @remainedLength  ) OPTION(RECOMPILE)

--：f_getPartSerialNo
CREATE FUNCTION [dbo].[f_getPartSerialNo]
(	
	-- Add the parameters for the function here
	@prefix varchar(40),
	@serialLength int, 
	@remainedLength int
)
RETURNS TABLE 
AS
RETURN 
(
	SELECT MIN(LX_IMA01) AS LX_IMA01
	FROM (
		SELECT PART_POOL.LX_IMA01, PART.LX_IMA01 AS IMA001
		FROM (
			SELECT @prefix + NUM AS LX_IMA01
			FROM NUMPOOL
			WHERE SerialLength = @serialLength
		) PART_POOL
		LEFT JOIN (
			SELECT lx_ima01
			FROM innovator.PART
			WHERE PART.LX_IMA01 LIKE @prefix+'%'
				AND IS_CURRENT = '1'
		) Part
		ON PART_POOL.LX_IMA01 = SUBSTRING(PART.LX_IMA01, 1, LEN(PART.LX_IMA01) - @remainedLength)
) X
WHERE IMA001 IS NULL
)
GO

3種查詢執行計劃：

1，傳值：

2，傳參

3，使用OPTION(RECOMPILE)，執行計劃與傳值一致。