初涉SQL Server性能问题（3/4）：列出阻塞的会话

/*****************************************************************************************
STEP 4: List the Open session with transaction which is not active
****************************************************************************************/
SELECT es.session_id,
es.login_name,
es.HOST_NAME,
DB_NAME(SP.dbid) AS DatabaseName,
sp.lastwaittype,
est.TEXT,cn.last_read,
cn.last_write,
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)))))
)ELSE es.program_name END  AS program_name
FROM sys.dm_exec_sessions es
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
INNER JOIN sys.sysprocesses SP ON SP.spid=es.session_id
LEFT OUTER JOIN sys.dm_exec_requests er  ON st.session_id = er.session_id
AND er.session_id IS NULL
CROSS APPLY sys.dm_exec_sql_text(cn.most_recent_sql_handle) est
WHERE (DATEDIFF(SS,cn.last_read,GETDATE())+DATEDIFF(SS,cn.last_write,GETDATE()))>30
AND lastwaittype NOT IN ('BROKER_RECEIVE_WAITFOR' ,'WAITFOR')
GO