87.You are managing an Oracle Database 11g database running in ARCHIVELOG mode. The Flash Recovery Area is specified as the destination for the archived redo log files. You notice this warning in the alert log file: ORA-19815: WARNING: db_recovery_file_dest_size of 3221225472 bytes is 100.00% used,and has 0 remaining bytes available. What would you do to reclaim the used space in the Flash Recovery Area? (Choose two.) A.Back up the Flash Recovery Area. B.Decrease the retention time for the database backup and flashback log files. C.Manually delete all the archived log files from the Flash Recovery Area by using operating system (OS) commands. D.Manually delete all the expired backup sets from the Flash Recovery Area by using operating system (OS) commands. 答案：AB 解析：fra中的文件时oracle自动管理的，手动删除文件后，oracle并不会识别，因此不会释放空间，所以CD是错误的，如果想手动删除 那么需要在操作系统上执行crosscheck或者将expired的备份删除。 参考：https://docs.oracle.com/cd/B16240_01/doc/doc.102/e16282/rac_database_help/rac_database_recovery_area_free_space.html To free up space from the Flash Recovery Area,follow these steps: 1.Consider changing your RMAN retention policy. If you are using dataguard,then consider changing your RMAN archivelog deletion policy. 2.Back up files to a tertiary device,such as tape using the RMAN command BACKUP RECOVERY AREA. 3.Add disk space and increase the db_recovery_file_dest_size parameter to reflect the new space. 4.Delete unncessary files using the RMAN DELETE command. If an OS command was used to delete files,then use RMAN CROSSCHECK and DELETE EXPIRED commands.