RMAN> backup database plus archivelog;
此命令将触发以下操作：
1、首先，进程使用alter system archivelog current命令完成了日志切换操作。
2、进程将现存所有归档重做日志备份
3、开始执行实际的数据库备份操作，此时会发生一次日志切换（alter system archivelog current），同时RMAN备份剩余的归档重做日志（使用backup archivelog all命令）。
4、执行控制文件和服务器参数文件的自动备份操作。
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案例：
1、查看备份前的日志信息
17:13:50 SYS@ prod>select group#,sequence#,thread#,status from v$log;
GROUP# SEQUENCE# THREAD# STATUS
---------- ---------- ---------- ----------------
1 16 1 CURRENT
2 14 1 INACTIVE
3 15 1 INACTIVE
Elapsed: 00:00:00.05
2、执行备份
RMAN> backup database plus archivelog;
Starting backup at 03-JUL-14
current log archived
using channel ORA_DISK_1
channel ORA_DISK_1: starting archived log backup set
channel ORA_DISK_1: specifying archived log(s) in backup set
input archived log thread=1 sequence=13 RECID=41 STAMP=851966028
input archived log thread=1 sequence=14 RECID=42 STAMP=851966028
input archived log thread=1 sequence=15 RECID=43 STAMP=851966030
input archived log thread=1 sequence=16 RECID=44 STAMP=851966141
channel ORA_DISK_1: starting piece 1 at 03-JUL-14
channel ORA_DISK_1: finished piece 1 at 03-JUL-14
piece handle=/u01/app/oracle/product/11.2.0/db_1/dbs/0kpcfu5t_1_1 tag=TAG20140703T171541 comment=NONE
channel ORA_DISK_1: backup set complete, elapsed time: 00:00:04
Finished backup at 03-JUL-14
Starting backup at 03-JUL-14
using channel ORA_DISK_1
channel ORA_DISK_1: starting full datafile backup set
channel ORA_DISK_1: specifying datafile(s) in backup set
input datafile file number=00001 name=/u01/app/oracle/oradata/prod/system01.dbf
input datafile file number=00002 name=/u01/app/oracle/oradata/prod/sysaux01.dbf
input datafile file number=00008 name=/u01/app/oracle/oradata/prod/perftbs01.dbf
input datafile file number=00004 name=/u01/app/oracle/oradata/prod/users01.dbf
input datafile file number=00005 name=/u01/app/oracle/oradata/prod/example01.dbf
input datafile file number=00007 name=/u01/app/oracle/oradata/prod/undotbs2.dbf
input datafile file number=00006 name=/u01/app/oracle/oradata/prod/tbs1.dbf
input datafile file number=00003 name=/u01/app/oracle/oradata/prod/undotbs1.dbf
channel ORA_DISK_1: starting piece 1 at 03-JUL-14
channel ORA_DISK_1: finished piece 1 at 03-JUL-14
piece handle=/u01/app/oracle/product/11.2.0/db_1/dbs/0lpcfu61_1_1 tag=TAG20140703T171545 comment=NONE
channel ORA_DISK_1: backup set complete, elapsed time: 00:01:26
Finished backup at 03-JUL-14
Starting backup at 03-JUL-14
current log archived
using channel ORA_DISK_1
channel ORA_DISK_1: starting archived log backup set
channel ORA_DISK_1: specifying archived log(s) in backup set
input archived log thread=1 sequence=17 RECID=45 STAMP=851966231
channel ORA_DISK_1: starting piece 1 at 03-JUL-14
channel ORA_DISK_1: finished piece 1 at 03-JUL-14
piece handle=/u01/app/oracle/product/11.2.0/db_1/dbs/0mpcfu8o_1_1 tag=TAG20140703T171712 comment=NONE
channel ORA_DISK_1: backup set complete, elapsed time: 00:00:01
Finished backup at 03-JUL-14
Starting Control File and SPFILE Autobackup at 03-JUL-14
piece handle=/u01/app/oracle/product/11.2.0/db_1/dbs/c-239333010-20140703-00 comment=NONE
Finished Control File an