RMAN I/O等候查看

RMAN I/O等待查看
SELECT b.io_count,
         b.ready,
         b.short_waits,
         b.long_waits,
         b.long_waits / b.io_count,
         b.filename
  FROM   v$backup_async_io b;
 
如果LONG_WAITS/IO_COUNT 过高 则说明有问题