如何粗略计算adg或ogg所需要使用的带宽

《How To Calculate The Required Network Bandwidth Transfer Of Redo In Data Guard Environments (Doc ID 736755.1) 》。

通过以下可统计主库REDO数据的产生速率： 

select thread#,
       sequence#,
       blocks * block_size / 1024 / 1024 MB,
       (next_time - first_time) * 86400 sec,
       (blocks * block_size / 1024 / 1024) / ((next_time - first_time) * 86400) "MB/s"
  from v$archived_log
where ((next_time - first_time) * 86400 <> 0)
   and first_time between
       to_date('2018/01/29 08:00:00', 'YYYY/MM/DD HH24:MI:SS') and
       to_date('2018/01/29 11:00:00', 'YYYY/MM/DD HH24:MI:SS')
   and dest_id = 2
 order by first_time;

通过主库REDO数据的产生速率来计算所需要的网络带宽： 

Required bandwidth = ((Redo rate bytes per sec. / 0.75) * 8) / 1,000,000 = bandwidth in Mbps

（除以0.75表示网络传输中其他的网络开销占用25%左右）。

参考：ADG设计及优化的最佳实践