SQL server 备份job堵塞查询

SELECT req.session_id,
database_name = db_name(req.database_id),
req.status,
req.blocking_session_id,
req.command,
[sql_text] = Substring(txt.TEXT, (req.statement_start_offset / 2) + 1, (
(
CASE req.statement_end_offset
WHEN - 1 THEN Datalength(txt.TEXT)
ELSE req.statement_end_offset
END - req.statement_start_offset
) / 2
) + 1),
req.percent_complete,
req.start_time,
cpu_time_sec = req.cpu_time / 1000,
granted_query_memory_mb = CONVERT(NUMERIC(8, 2), req.granted_query_memory / 128.),
req.reads,
req.logical_reads,
req.writes,
eta_completion_time = DATEADD(ms, req.[estimated_completion_time], GETDATE()),
elapsed_min = CONVERT(NUMERIC(6, 2), req.[total_elapsed_time] / 1000.0 / 60.0),
remaning_eta_min = CONVERT(NUMERIC(6, 2), req.[estimated_completion_time] / 1000.0 / 60.0),
eta_hours = CONVERT(NUMERIC(6, 2), req.[estimated_completion_time] / 1000.0 / 60.0/ 60.0),
wait_type,
wait_time_sec = wait_time/1000,
wait_resource
FROM sys.dm_exec_requests as req WITH(NOLOCK)
CROSS APPLY sys.dm_exec_sql_text(req.sql_handle) as txt
WHERE req.session_id>50
AND command IN ('BACKUP DATABASE', 'BACKUP LOG', 'RESTORE DATABASE', 'RESTORE LOG');