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SET STATISTICS TIME ON
DECLARE @Process_Instance_Id nVarChar(48)
SET @Process_Instance_Id = 'nvevrqt6e25wzpvhpa95htn4h2.%'
SELECT 1
FROM ITWORKITEMS I
WHERE I.WIREFID LIKE @Process_Instance_Id
ORDER BY I.WISTART DESC, I.PRINSTUID DESC, I.WIID DESC
SET STATISTICS TIME ON
DECLARE @Process_Instance_Id nVarChar(48)
SET @Process_Instance_Id = 'nvevrqt6e25wzpvhpa95htn4h2.%'
SELECT 1
FROM ITWORKITEMS I
WHERE I.WIREFID LIKE 'nvevrqt6e25wzpvhpa95htn4h2.%'
ORDER BY I.WISTART DESC, I.PRINSTUID DESC, I.WIID DESC
SET STATISTICS TIME ON
DECLARE @Process_Instance_Id nVarChar(48)
SET @Process_Instance_Id = 'nvevrqt6e25wzpvhpa95htn4h2.%'
SELECT 1
FROM ITWORKITEMS I
WHERE I.WIREFID LIKE @Process_Instance_Id
ORDER BY I.WISTART DESC, I.PRINSTUID DESC, I.WIID DESC
DBCC FREEPROCCACHE
DBCC DROPCLEANBUFFERS
CHECKPOINT
SET STATISTICS TIME ON
DECLARE @Process_Instance_Id nVarChar(48)
SET @Process_Instance_Id = 'nvevrqt6e25wzpvhpa95htn4h2.%'
SELECT 1
FROM ITWORKITEMS I
WHERE I.WIREFID LIKE 'nvevrqt6e25wzpvhpa95htn4h2.%'
ORDER BY I.WISTART DESC, I.PRINSTUID DESC, I.WIID DESC
DBCC FREEPROCCACHE
DBCC DROPCLEANBUFFERS
CHECKPOINT
set statistics time on
select * from mytemptable where gctxmc like '%06%'
set statistics time on
declare @con varchar(20)
set @con='%06%'
select * from mytemptable where gctxmc like @con
--在我这like后面接常量和变量的执行速度是一样的
--请在执行第二个查询前加入以下语句后再试:
dbcc dropcleanbuffers --清除缓冲区的功能,因为第一个执行时已经将数据写到缓冲区中,第二次再执行就直接读缓冲区了,所以先执行这个语句清除缓冲区后再试结果
--请在执行第二个查询前加入以下语句后再试:
dbcc dropcleanbuffers --清除缓冲区的功能,因为第一个执行时已经将数据写到缓冲区中,第二次再执行就直接读缓冲区了,所以先执行这个语句清除缓冲区后再试结果