初涉SQL Server性能问题（3/4）：列出阻塞的会话

原文: 初涉SQL Server性能问题（3/4）：列出阻塞的会话

在 初涉SQL Server性能问题（2/4）里，我们讨论了列出等待资源或正运行的会话脚本。这篇文章我们会看看如何列出包含具体信息的话阻塞会话清单。

 1 /******************************************************************************************/

 2 CREATE FUNCTION [dbo].dba_GetStatementForSpid

 3 (  

 4    @spid SMALLINT  

 5 )  

 6 RETURNS NVARCHAR(4000)  

 7 BEGIN  

 8    DECLARE @SqlHandle BINARY(20)  

 9    DECLARE @SqlText NVARCHAR(4000)  

10    SELECT @SqlHandle = sql_handle   

11       FROM sys.sysprocesses WITH (nolock) WHERE   spid = @spid  

12    SELECT @SqlText = [text] FROM   

13       sys.dm_exec_sql_text(@SqlHandle)  

14    RETURN @SqlText  

15 END  

16 GO

17 

18 /*****************************************************************************************

19 STEP 4: List the current blocking session information

20 ****************************************************************************************/

21 

22 SELECT

23 es.session_id,

24 es.HOST_NAME,

25 DB_NAME(database_id) AS DatabaseName, 

26 CASE WHEN es.program_name LIKE '%SQLAgent - TSQL JobStep%' THEN (SELECT 'SQL AGENT JOB: '+name FROM msdb..sysjobs WHERE job_id=MASTER.DBO.ConvertStringToBinary (LTRIM(RTRIM((SUBSTRING(es.program_name,CHARINDEX('(job',es.program_name,0)+4,35)))))) 

27 ELSE es.program_name END  AS program_name ,

28 es.login_name ,

29 bes.session_id AS Blocking_session_id,

30 MASTER.DBO.dba_GetStatementForSpid(es.session_id) AS [Statement],

31 bes.HOST_NAME AS Blocking_hostname,

32 CASE WHEN Bes.program_name LIKE '%SQLAgent - TSQL JobStep%' THEN

33 (SELECT 'SQL AGENT JOB: '+name FROM msdb..sysjobs WHERE job_id=

34 MASTER.DBO.ConvertStringToBinary 

35 (LTRIM(RTRIM((SUBSTRING(Bes.program_name,CHARINDEX('(job',es.program_name,0)+4,35))))))

36 ELSE Bes.program_name END  AS Blocking_program_name,

37 bes.login_name AS Blocking_login_name,

38   MASTER.DBO.dba_GetStatementForSpid(bes.session_id ) AS [Blocking Statement]

39 FROM sys.dm_exec_requests S 

40 INNER JOIN sys.dm_exec_sessions  es ON es.session_id=s.session_id

41 INNER JOIN sys.dm_exec_sessions  bes ON bes.session_id=s.blocking_session_id

这个脚本会列出被阻塞和正阻塞的语句信息，帮助我们进行问题分析。下面的脚本会帮助我们列出已经打开事务但未活动的会话，即打开事务，但上30秒内都没执行任何语句的会话。

 1 /*****************************************************************************************

 2 STEP 4: List the Open session with transaction which is not active

 3 ****************************************************************************************/

 4 SELECT es.session_id, 

 5 es.login_name, 

 6 es.HOST_NAME, 

 7 DB_NAME(SP.dbid) AS DatabaseName,

 8 sp.lastwaittype,

 9 est.TEXT,cn.last_read, 

10 cn.last_write, 

11 CASE WHEN es.program_name LIKE '%SQLAgent - TSQL JobStep%' THEN(SELECT 'SQL AGENT JOB: '+name FROM msdb..sysjobs WHERE job_id=MASTER.DBO.ConvertStringToBinary (LTRIM(RTRIM((SUBSTRING(es.program_name,CHARINDEX('(job',es.program_name,0)+4,35)))))

12 )ELSE es.program_name END  AS program_name 

13 FROM sys.dm_exec_sessions es

14 INNER JOIN sys.dm_tran_session_transactions st ON es.session_id = st.session_id                INNER JOIN sys.dm_exec_connections cn ON es.session_id = cn.session_id 

15 INNER JOIN sys.sysprocesses SP ON SP.spid=es.session_id                 

16 LEFT OUTER JOIN sys.dm_exec_requests er  ON st.session_id = er.session_id   

17 AND er.session_id IS NULL             

18 CROSS APPLY sys.dm_exec_sql_text(cn.most_recent_sql_handle) est                

19 WHERE (DATEDIFF(SS,cn.last_read,GETDATE())+DATEDIFF(SS,cn.last_write,GETDATE()))>30

20 AND lastwaittype NOT IN ('BROKER_RECEIVE_WAITFOR' ,'WAITFOR')                                  

21 GO