注意：当apply动作没有进行，但是日志不断传输的时候，standby redo log中只是保存最新的当前log，与Primary相匹配。过期的日志是会作为归档保存在归档日志列表中。
此时alert log中的信息如下：
Mon Oct 19 11:21:57 2015
Archived Log entry 18 added for thread 1 sequence 39 ID 0xfac9d167 dest 1:
Mon Oct 19 11:21:57 2015
Primary database is in MAXIMUM PERFORMANCE mode
RFS[13]: Assigned to RFS process 15589
RFS[13]: Selected log 4 for thread 1 sequence 40 dbid -87496857 branch 892734889
Mon Oct 19 11:21:58 2015
Archived Log entry 19 added for thread 1 sequence 40 ID 0xfac9d167 dest 1:
Mon Oct 19 11:21:58 2015
Primary database is in MAXIMUM PERFORMANCE mode
RFS[14]: Assigned to RFS process 15591
RFS[14]: Selected log 4 for thread 1 sequence 41 dbid -87496857 branch 892734889
Mon Oct 19 11:22:02 2015
Archived Log entry 20 added for thread 1 sequence 41 ID 0xfac9d167 dest 1:
Mon Oct 19 11:22:02 2015
Primary database is in MAXIMUM PERFORMANCE mode
RFS[15]: Assigned to RFS process 15593
RFS[15]: Selected log 4 for thread 1 sequence 42 dbid -87496857 branch 892734889
注意：这个日志告诉我们，在standby端，是依次的找可用的standby redo log来使用。如果找到可用的standby redo log，就直接使用好了。