delete noprompt archivelog

刪除7天前已經備份的歸檔日志

delete noprompt archivelog all completed before 'sysdate - 7';

備份沒有備份的歸檔日志

backup archivelog all not backed up;

不備份已經備份1次的歸檔日志

backup archivelog all not backed up 1 times;　　

歸檔日志備份過兩次的， 第三次是不進行備份的

backup archivelog all not backed up 2 times;　

crosscheck archivelog all;
delete noprompt archivelog all completed before 'sysdate - 1/2' BACKED UP 1 TIMES TO DEVICE TYPE SBT;

delete noprompt archivelog all backed up 1 times to DEVICE TYPE SBT completed before 'sysdate-1/2';

backup archivelog all not backed up 1 times;　　---- # 不備份上次已經備份的歸檔
crosscheck archivelog all;
resync catalog;