在SQL Server 2005和2008获取数据库备份或者恢复完成百分比

If you want to see how far along your restore or backup is then you can do this...
如果你想知道备份或者恢复进度如何，你可以如此操作：
 
select percent_complete
from sys.dm_exec_requests
where session_id = 53
 
This is in addition to the STATS = n option on the BACKUP/RESTORE commands.
该语句是对备份恢复命令中STATS = n选项的一个补充。
 
原文： http://sqlblogcasts.com/blogs/tonyrogerson/archive/2009/06/19/determining-backup-or-restore-percent-complete-in-sql-server-2008-and-sql-server-2005.aspx