以Oracle賬戶登錄到數據庫，執行以下命令：
1. 進入rman
2. connect target /
3. crosscheck archivelog all;
4. delete expired archivelog all;
5. DELETE ARCHIVELOG ALL COMPLETED BEFORE 'SYSDATE-7';——這個是刪除七天前的歸檔日志
DELETE ARCHIVELOG FROM TIME 'SYSDATE-7'; 刪除從7天前到現在的全部日志,慎用
6. crosscheck archivelog all;
7. delete expired archivelog all;
8. 退出：exit