ADG 備庫不允許切換日誌

備庫數據文件是不允許寫數據，切換日誌是需要寫數據到數據文件中的。爲什麼rman備份可以，是因爲rman備份寫的是控制文件~

1、備庫演示，會報錯，數據庫爲打開。

SQL> archive log list;
Database log mode          Archive Mode
Automatic archival         Enabled
Archive destination        /arch
Oldest online log sequence     4132
Next log sequence to archive   0
Current log sequence           4134
SQL> alter system archive log current;
alter system archive log current
*
ERROR at line 1:
ORA-01109: database not open

SQL>