众所周知，Oracle Rman的retention policy 在任意一个时刻：只能有一个生效。也就是说，两个retention policy 之间是or的关系。
如下使用catalog数据库完成，因为backup 命令的keep forever关键字只支持catalog
[oracle@vm21 ~]$ rman target / catalog rc/rc@rc Recovery Manager: Release 10.2.0.1.0 - Production on Mon Dec 15 21:18:06 2014 Copyright (c) 1982, 2005, Oracle. All rights reserved. connected to target database: PROD (DBID=275920358) connected to recovery catalog database RMAN> backup database format '/home/oracle/keep_test_%U' keep forever nologs; Starting backup at 15-DEC-14 allocated channel: ORA_DISK_1 channel ORA_DISK_1: sid=272 devtype=DISK backup will never be obsolete archived logs required to recover from this backup will not be kept RMAN-00571: =========================================================== RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS =============== RMAN-00571: =========================================================== RMAN-03002: failure of backup command at 12/15/2014 21:20:13 RMAN-06533: KEEP ... NOLOGS option cannot be used when datafiles are fuzzy --->该语法是不行的：fuzzy状态是 database open时，datafile的状态（该状态可以从v$datafile_header中获得） RMAN>backup database format '/home/oracle/keep_test_%U' keep forever logs; Starting backup at 15-DEC-14 using channel ORA_DISK_1 backup will never be obsolete archived logs required to recover from this backup will expire when this backup expires channel ORA_DISK_1: starting full datafile backupset channel ORA_DISK_1: specifying datafile(s) in backupset input datafile fno=00004 name=/u01/app/oracle/oradata/PROD/disk1/example_1.dbf input datafile fno=00001 name=/u01/app/oracle/oradata/PROD/disk1/system01.dbf input datafile fno=00003 name=/u01/app/oracle/oradata/PROD/disk1/sysaux01.dbf input datafile fno=00002 name=/u01/app/oracle/oradata/PROD/disk1/undotbs01.dbf input datafile fno=00009 name=/u01/app/oracle/oradata/PROD/disk1/r_1.dbf input datafile fno=00007 name=/u01/app/oracle/oradata/PROD/disk1/users_1.dbf input datafile fno=00008 name=/u01/app/oracle/oradata/PROD/disk1/oltp_1.dbf input datafile fno=00005 name=/u01/app/oracle/oradata/PROD/disk1/indx_1.dbf input datafile fno=00006 name=/u01/app/oracle/oradata/PROD/disk1/tools_1.dbf channel ORA_DISK_1: starting piece 1 at 15-DEC-14 piece handle=/home/oracle/keep_test_0spq8ni4_1_1 tag=TAG20141215T212732 comment=NONE -->备份的开始时间是：20141215T212732 channel ORA_DISK_1: backup set complete, elapsed time: 00:01:55 Finished backup at 15-DEC-14 Starting Control File and SPFILE Autobackup at 15-DEC-14 piece handle=/home/oracle/backup/control/c-275920358-20141215-00 comment=NONE Finished Control File and SPFILE Autobackup at 15-DEC-14 RMAN> [oracle@vm21 ~]$ sqlplus / as sysdba SQL*Plus: Release 10.2.0.1.0 - Production on Mon Dec 15 21:29:56 2014 Copyright (c) 1982, 2005, Oracle. All rights reserved. Connected to: Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Production With the Partitioning, OLAP and Data Mining options SQL> archive log list; Database log mode Archive Mode Automatic archival Enabled Archive destination /home/oracle/arch Oldest online log sequence 20 Next log sequence to archive 23 Current log sequence 23 ------------------------>此时的日志序列号是23 SQL> alter system switch logfile; System altered. SQL> / System altered. 以下略去归档的切换过程