Oracle 資料庫支援兩種運行模式:歸檔模式與非歸檔模式。歸檔模式旨在提高可恢復性,正式生產環境必須啟用,並需搭配完備備份策略——單純啟用歸檔無備份策略反增運維負擔。
SQL> SHUTDOWN IMMEDIATE;
Database closed.
Database dismounted.
Oracle instance shut down.
SQL> STARTUP MOUNT;
Oracle instance started.
Total System Global Area 101782828 bytes
...
Database mounted.
SQL> ALTER DATABASE ARCHIVELOG;
Database altered.
SQL> ALTER DATABASE OPEN;
Database altered.
SQL> ARCHIVE LOG LIST;
Database log mode Archive Mode
Automatic archival Enabled
Archive destination /opt/Oracle/oradata/conner/archive
Oldest online log sequence 148
Next log sequence to archive 151
Current log sequence 151
ARCHIVE LOG LIST 可即時確認:
SQL> SHUTDOWN IMMEDIATE;
SQL> STARTUP MOUNT;
SQL> ALTER DATABASE NOARCHIVELOG;
SQL> ALTER DATABASE OPEN;
歸檔模式是資料庫可恢復性的基石,配合 RMAN 備份策略,構建企業級資料保護防線。切記:無備份的歸檔模式只是佔用磁碟空間的累贅。