ORPHAN参数报告在同一个标记 （INCARNATION）中间断的备份，前一个备份和后一个备份不连续，也就是说同一个标记（INCARNATION）中两个备份中间有被删除的备份。
REPORT OBSOLETE ORPHAN;
删除过期备份：
# delete obsolete backups displayed when you issue REPORT OBSOLETE
DELETE OBSOLETE;
# delete obsolete backups according to a specified recovery window
DELETE OBSOLETE RECOVERY WINDOW OF 7 DAYS;
# delete obsolete backups according to a specified redundancy
DELETE OBSOLETE REDUNDANCY = 2;
报告数据库方案：
REPORT SCHEMA AT TIME 'SYSDATE-14'; # schema as it was two weeks ago
REPORT SCHEMA AT SCN 1000; # schema as it was at scn 1000
REPORT SCHEMA AT SEQUENCE 100 THREAD 1; # schema as it was at sequence 100
REPORT SCHEMA AT SCN 1000;
