**环境描述：** DG环境强制read write打开备库为主库，想要从主库重新拷贝控制文件给备库，进而再将其恢复为备库状态。 **操作流程：** ``` 1.从主库拷贝了一份控制文件 alter database create standby controlfile as '/home/oracle/standby.ctl'; 2.关闭read write打开的备库，重新恢复控制文件， 3.进行数据文件重命名 4.此时后台警告日志是可以正常接收从主库传输过来的日志的 5.当我启动MRP进程进行日志应用时，前台无异常报错，后台警告日志中MRP异常关闭情况。 ``` **摘取部分警告日志：** ORA-19909: datafile 1 belongs to an orphan incarnation ORA-01110: data file 1: '/oracle/app/oradata/prod/system01.dbf' ``` alter database recover managed standby database disconnect from session Attempt to start background Managed Standby Recovery process (prod) Thu Aug 20 18:51:38 2020 MRP0 started with pid=26, OS id=3446 MRP0: Background Managed Standby Recovery process started (prod) started logmerger process Thu Aug 20 18:51:43 2020 Managed Standby Recovery not using Real Time Apply MRP0: Detected orphaned datafiles! Recovery will possibly be retried after flashback... Errors in file /oracle/app/diag/rdbms/prod/prod/trace/prod_pr00_3448.trc: ORA-19909: datafile 1 belongs to an orphan incarnation ORA-01110: data file 1: '/oracle/app/oradata/prod/system01.dbf' Recovery Slave PR00 previously exited with exception 19909 Completed: alter database recover managed standby database disconnect from session Thu Aug 20 18:52:03 2020 MRP0: Background Media Recovery process shutdown (prod) ``` **进入RMAN查看了数据库当前化身信息：** ``` RMAN> list incarnation using target database control file instead of recovery catalog List of Database Incarnations DB Key Inc Key DB Name DB ID STATUS Reset SCN Reset Time ------- ------- -------- ---------------- --- ---------- ---------- 1 1 PROD 457994418 PARENT 1 24-AUG-13 2 2 PROD 457994418 CURRENT 925702 19-JUL-20 ``` **查看数据文件头记录的resetogs信息.//可以看出明显与控制文件中SCN不一致** ``` SQL> select file#, status, checkpoint_change#, checkpoint_time, resetlogs_change#, resetlogs_time, fuzzy from v$datafile_header; FILE# STATUS CHECKPOINT_CHANGE# CHECKPOIN RESETLOGS_CHANGE# RESETLOGS FUZ ---------- ------- ------------------ --------- ----------------- --------- --- 1 ONLINE 1155722 20-AUG-20 1155722 20-AUG-20 NO 2 ONLINE 1155722 20-AUG-20 1155722 20-AUG-20 NO 3 ONLINE 1155722 20-AUG-20 1155722 20-AUG-20 NO 4 ONLINE 1155722 20-AUG-20 1155722 20-AUG-20 NO 5 ONLINE 1155722 20-AUG-20 1155722 20-AUG-20 NO ``` **根据文档MRP Recovery Failed With ORA-19909 [ID 554358.1]** **尝试解决：** ``` RMAN> reset database to incarnation 1 SQL> recover standby database; ORA-00283: recovery session canceled due to errors ORA-19909: datafile 1 belongs to an orphan incarnation ORA-01110: data file 1: '/oracle/app/oradata/prod/system01.dbf' //还是不行，官方Mos中记录的问题是由于主库与备库不处于同一个化身 而在我当前环境主备库化身线是一致的。 ``` **主库化身线：** ``` RMAN> list incarnation; using target database control file instead of recovery catalog List of Database Incarnations DB Key Inc Key DB Name DB ID STATUS Reset SCN Reset Time ------- ------- -------- ---------------- --- ---------- ---------- 1 1 PROD 457994418 PARENT 1 24-AUG-13 2 2 PROD 457994418 CURRENT 925702 19-JUL-20 ``` **备库化身线：** ``` RMAN> list incarnation using target database control file instead of recovery catalog List of Database Incarnations DB Key Inc Key DB Name DB ID STATUS Reset SCN Reset Time ------- ------- -------- ---------------- --- ---------- ---------- 1 1 PROD 457994418 PARENT 1 24-AUG-13 2 2 PROD 457994418 CURRENT 925702 19-JUL-20 ``` 看来当强制read write打开备库为主库时，如果想要再次将其恢复成备库，仅仅从主库拷贝一个备份的控制文件是不可以的，还需要重新同步数据文件。