Oracle 12c DG备库启动报错：SQL> alter database open read only;alter database open read only*ERROR at line 1:ORA-10458: standby database requires recoveryORA-01196: file 1 is inconsistent due to a failed media recovery sessionORA-01110: data file 1: '/data/oracle/oradata/WMSPROD/system01.dbf' 原因：备库丢失归档日志。ORA-16016: archived log for thread 1 sequence# 4673 unavailableRecovery interrupted!Some recovered datafiles maybe left media fuzzy解决办法：从主库拷贝过来相应的归档日志进行恢复。
1)备库查询：SQL>select process,client_process,sequence#,status from v$managed_standby;//定位正在应用的日志文件
select max(sequence#) from v$archived_log;
2)主库查询：SQL> select process,client_process,sequence#,status from v$managed_standby;//查询主库当前写到的日志文件
select max(sequence#) from v$archived_log;
3)对比备库与主库之间的待传输应用日志文件，从主库拷贝到备库归档路径
4)备库注册，注册备库缺失的最近的归档日志即可
ALTER DATABASE REGISTER PHYSICAL LOGFILE '/u01/app/oracle/archivelog/xxx.dbf' ;
5)备库应用redo
alter database recover managed standby database disconnect from session;
问题解决。
