oracle DG 备库启动报错如下
SQL> startup
ORACLE instance started.
Total System Global Area 1.0689E+11 bytes
Fixed Size 2265864 bytes
Variable Size 1.2885E+10 bytes
Database Buffers 9.3952E+10 bytes
Redo Buffers 55242752 bytes
Database mounted.
ORA-10458: standby database requires recovery
ORA-01196: file 1 is inconsistent due to a failed media recovery session
ORA-01110: data file 1: '/oradata/orcl/datafile1/system01.dbf'
解决办法：
在备库执行
shutdown immediate;
startup mount
SQL> alter database recover managed standby database using current logfile disconnect from session;
Database altered.
在主库上切换日志
alter system switch logfile;多切换几次
如果返回结果”APPLIED”都是“YES”或者只有最后一个是“NO”的话，说明全部归档日志全部已经归档完了，此时到备库上上操作：
SQL> alter database recover managed standby database cancel;
Database altered.
SQL> alter database open;
Database altered.
SQL> ALTER DATABASE RECOVER MANAGED STANDBY DATABASE USING CURRENT LOGFILE DISCONNECT FROM SESSION;
Database altered.
SQL> select open_mode from v$database;
OPEN_MODE
READ ONLY WITH APPLY
解决。。。搞定。。。