1.主库添加临时文件
SQL> create temporary tablespace temp_1 tempfile '+datadg' size 10m;

Tablespace created.

SQL> alter system archive log current;

System altered.

col file_name for a50;
set lines 150
select file_name,tablespace_name from dba_temp_files;

FILE_NAME                                          TABLESPACE_NAME
-------------------------------------------------- ------------------------------
+DATADG/ORCL/TEMPFILE/temp.265.954623079           TEMP
+DATADG/ORCL/TEMPFILE/temp_1.605.963692313         TEMP_1

SQL> 

2.查看备库
SQL> select open_mode from v$database;

OPEN_MODE
--------------------
READ ONLY WITH APPLY

SQL> col file_name for a50;
SQL> set lines 150
SQL> select file_name,tablespace_name from dba_temp_files;

FILE_NAME                                          TABLESPACE_NAME
-------------------------------------------------- ------------------------------
+DATADG/ORCLDG/TEMPFILE/temp.406.962961491         TEMP

SQL> 

--查看备库日志

*********************************************************************
WARNING: The following temporary tablespaces contain no files.
         This condition can occur when a backup controlfile has
         been restored.  It may be necessary to add files to these
         tablespaces.  That can be done using the SQL statement:

         ALTER TABLESPACE  ADD TEMPFILE

         Alternatively, if these temporary tablespaces are no longer
         needed, then they can be dropped.
           Empty temporary tablespace: TEMP_1
*********************************************************************

解决方法
备库直接添加一个临时文件

3.备库执行
SQL> alter tablespace temp_1 add tempfile '+datadg' size 10m;

Tablespace altered.

SQL> col file_name for a50;
SQL> set lines 150
SQL> select file_name,tablespace_name from dba_temp_files;

FILE_NAME                                          TABLESPACE_NAME
-------------------------------------------------- ------------------------------
+DATADG/ORCLDG/TEMPFILE/temp.406.962961491         TEMP
+DATADG/ORCLDG/TEMPFILE/temp_1.342.963694567       TEMP_1

重启备库，查看告警日志，无报错。

小结
1.主库添加临时表空间，备库数据字典存在表空间信息。
2.备库dba_temp_files数据字典不存在临时文件记录。
3.备库open状态直接添加一个临时文件即可。
4.ADG的文件管理方式和单机、RAC管理方式不同，需要大家多去测试。