Sql Server 2008清除選擇語句緩存？

Question

執行選擇語句後是否有可能清除緩存？

我試着用我的一個sql，第一次執行它時，它返回3.15分鐘和第二次（改變任何東西）它返回2.55分鐘。

對我來說，測試sql的實際性能是一種單調乏味的工作。

我發現在Sql Server 2005上有緩存在this後。

我正確的緩存有sql server 2008嗎？

Answer 1

這是我爲了同樣的目的做：

DBCC FREEPROCCACHE 
DBCC DROPCLEANBUFFERS 
GO 
DROP TABLE [WHATEVER I NEED TO DROP] 
GO 
TRUNCATE TABLE [WHATEVER I NEED TO EMPTY] 
GO 
UPDATE [WHATEVER HAS TO BE "RESET"] 
GO 
[DO REST OF "RESET ACTIONS" HERE] 
USE [YOUR DATABASE NAME] 
GO
 

DECLARE @start_time datetime, @end_time datetime, @miliseconds int
 

DECLARE @ALL_YOUR_VARS -- _YOU'LL_USE_WHILE_YOU_MEASURE /* BECAUSE YOU DON'T WANT TO MEASURE THE TIME SPENT ON TEMP VARS YOU CREATE FOR MEASURING EXEC TIME ONLY */
 

-- TODO: SET VARS' VALUES HERE, SAME REASON AS ABOVE
 

SET @start_time = GETDATE()
 

-- [EXECUTE ALL YOUR STATEMENTS HERE] -- [YOU WANT TO MEASURE]
 

SET @end_time = GETDATE() SET @miliseconds = DATEDIFF(ms, @start_time, @end_time) SELECT @start_time, @end_time, CAST(@miliseconds AS VARCHAR(max)) + ' ms' GO

編輯：差點忘了！您也可以在開始測量之前刪除所有活動連接到您的數據庫（在執行下面的代碼後，請不要忘記創建一個新的連接作爲實際的即時窗口，從中運行查詢也將斷開連接!!!）

USE master 
GO
 

SET NOCOUNT ON DECLARE @DBName varchar(50) DECLARE @spidstr varchar(8000) DECLARE @ConnKilled smallint SET @ConnKilled=0 SET @spidstr = ''
 

Set @DBName = 'YOURDBNAMEHERE' IF db_id(@DBName) < 4 BEGIN PRINT 'Connections to system databases cannot be killed' RETURN END SELECT @spidstr=coalesce(@spidstr,',')+'kill '+convert(varchar, spid)+ '; ' FROM master..sysprocesses WHERE dbid=db_id(@DBName)
 

IF LEN(@spidstr) > 0 BEGIN EXEC(@spidstr) SELECT @ConnKilled = COUNT(1) FROM master..sysprocesses WHERE dbid=db_id(@DBName) END