備庫數據文件是不容許寫數據,切換日誌是須要寫數據到數據文件中的。爲何rman備份能夠,是由於rman備份寫的是控制文件~數據庫
一、備庫演示,會報錯,數據庫爲打開。ide
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>