情景：
Dataguard 物理备库执行恢复报错：
Errors in file /home/u01/app/diag/rdbms/rzorcl11g/ORCL/trace/ORCL_pr00_35893.trc:
ORA-01111: name for data file 20 is unknown – rename to correct file
ORA-01110: data file 20: ‘/home/u01/app/oracle/product/11.2.0/db_1/dbs/UNNAMED00020’
ORA-01157: cannot identify/lock data file 20 – see DBWR trace file
ORA-01111: name for data file 20 is unknown – rename to correct file
ORA-01110: data file 20: ‘/home/u01/app/oracle/product/11.2.0/db_1/dbs/UNNAMED00020’
Recovery Slave PR00 previously exited with exception 1111
MRP0: Background Media Recovery process shutdown (ORCL)
原因：参数standby_file_management 值是manual，导致主库增加数据文件时候备库没有自动增加。
SQL> show parameter standby_file_management
NAME TYPE VALUE
———————————— ———– ——————————
standby_file_management string MANUAL
SQL> select file#,name from v$datafile where file#=20;
FILE# NAME
———- —————————————————————————————-
20 /home/u01/app/oracle/product/11.2.0/db_1/dbs/UNNAMED00020
解决方法： 将该文件rename到正确的目录中，然后设置standby_file_management参数的值为auto。
SQL> alter database create datafile ‘/home/u01/app/oracle/product/11.2.0/db_1/dbs/UNNAMED00020’ as ‘/home/u01/app/oradata/orcl11g/fsownbox04.dbf’;
SQL> alter system set standby_file_management = auto;
再执行恢复：
SQL> alter database recover managed standby database disconnect from session;