在做主备切换的时候，需要将备库的联机日志文件清除(clear online redo logfile)，为了加快switchover的速度，Oracle10g在将备库置于manged standby状态的时候就提前将这个clear的动作做了，这个想法是好的，只是实现有点糟糕，会在alert里记录错误一堆错误：
Errors in file /u01/oracle/admin/ning/bdump/ning_mrp0_319584.trc: ORA-00367: checksum error in log file header ORA-00316: log 1 of thread 1, type 0 in header is not log file ORA-00312: online log 1 thread 1: ‘/u01/oracle/oradata/ning/redo01_01.dbf’ Clearing online redo logfile 1 /u01/oracle/oradata/ning/redo01_01.dbf Clearing online log 1 of thread 1 sequence number 3715 Tue Mar 4 19:00:07 2008 Errors in file /u01/oracle/admin/ning/bdump/ning_mrp0_319584.trc: ORA-19527: physical standby redo log must be renamed ORA-00312: online log 1 thread 1: ‘/u01/oracle/oradata/ning/redo01_01.dbf’ Clearing online redo logfile 1 complete
Oracle不承认这是bug，不过还是给出了解决方法：首先要在备库创建online redo logfile，然后设置log_file_name_convert参数，即使主备库日志文件的路径和名字都一样也要设置，不然还是会报ORA-19527。
找到了一段正式的解释
Cause
This is in fact an enhancement to the Dataguard product in 10gR2 ..
The goal here is to improve speed of switchover. Before this a switchover would require to clear the online logfiles before we can become a primary. In this release we attempt to clear the online logfiles when starting Managed Recovery.
If the files exist then they will be cleared, but if they do not exist we report the error and the MRP does not fail.
As an extra enhancement if the online redo logs do exist you must specify the log_file_name_convert parameter even if there is no difference in the name. This has been implemented to reduce the chances that the primary online redo logs are cleared when MRP starts. It is the equivalent of asking - Are you sure you want the logs to be called this....
If the log_file_name_convert parameter is not set then the ORA-19527 is reported and the log file is not cleared at this time..
Solution
Solution to stop both of these errors is to create the online redo logs and ensure log_file_name_convert is set.
友情参考链接：
http://www.taobaodba.com/html/80_oracle10g_standby_ora_00367_ora_19527.html
http://space.itpub.net/11258275/viewspace-666811
http://www.xifenfei.com/4388.html