实验为了证明如下：---
数据库版本 11.2.0.3.
RMAN备份中，归档日志、控制文件和数据文件不能放在同一个备份集里，因为数据文件所在的备份集以Oracel 数据块为最小单位，
而控制文件块大小为作为16384，16K。归档日志文件所在的备份集也是以操作
系统块为最小单位，此处为512字节。
所以归档日志文件备份集、控制文件备份集和数据文件备份集不能在同一个备份集里面。
---以上都是默认参数时的，当然可以使用piece=N或者maxpiecesize=1g之类参数来调整。
证明以上以后，创建不同块大小的表空间，测试不同块大小的表空间，也不能备份到同一个备份PIECE中。
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实验一：验证归档日志文件备份集、控制文件备份集和数据文件备份集不能在同一个备份集里面
当前数据库中数据文件、控制文件、日志文件块大小：
SQL> col name for a50
SQL> select file#,name,block_size from v$datafile;
FILE# NAME BLOCK_SIZE
---------- -------------------------------------------------- ----------
1 +DATA01/bys9/datafile/system.260.876770855 8192
2 +DATA01/bys9/datafile/sysaux.261.876770927 8192
3 +DATA01/bys9/datafile/undotbs1.262.876770987 8192
4 +DATA01/bys9/datafile/users.264.876771015 8192
SQL> select members,bytes/1024/1024 M,blocksize from v$log;
MEMBERS M BLOCKSIZE
---------- ---------- ----------
2 50 512
2 50 512
2 50 512
SQL> select name,block_size from v$controlfile;
NAME BLOCK_SIZE
-------------------------------------------------- ----------
+DATA01/bys9/controlfile/current.256.876770817 16384
+FLASH/bys9/controlfile/current.256.876770821 16384
########备份测试情况：
可以看到归档文件的备份集、数据文件的备份集、控制文件的备份集是不在同一个备份PIECE中。
RMAN> backup database format "/home/oracle/full_%d_%T_%s"
2> plus archivelog delete all input;
Starting backup at 12-MAY-15
current log archived
allocated channel: ORA_DISK_1
channel ORA_DISK_1: SID=41 device type=DISK
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=15 RECID=1 STAMP=877627122
input archived log thread=1 sequence=16 RECID=2 STAMP=879547905
input archived log thread=1 sequence=17 RECID=3 STAMP=879548073
channel ORA_DISK_1: starting piece 1 at 12-MAY-15
channel ORA_DISK_1: finished piece 1 at 12-MAY-15
piece handle=+FLASH/bys9/backupset/2015_05_12/annnf0_tag20150512t225434_0.263.879548075 tag=TAG20150512T225434 comment=NONE
channel ORA_DISK_1: backup set complete, elapsed time: 00:00:04
channel ORA_DISK_1: deleting archived log(s)
archived log file name=+FLASH/bys9/archivelog/2015_04_21/thread_1_seq_15.260.877627115 RECID=1 STAMP=877627122
archived log file name=+FLASH/bys9/archivelog/2015_05_12/thread_1_seq_16.261.879547905 RECID=2 STAMP=879547905
archived log file name=+FLASH/bys9/archivelog/2015_05_12/thread_1_seq_17.262.879548073 RECID=3 STAMP=879548073
Finished backup at 12-MAY-15
Starting backup at 12-MAY-15
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=+DATA01/bys9/datafile/system.260.876770855
input datafile file number=00002 name=+DATA01/bys9/datafile/sysaux.261.876770927
input datafile file number=00003 name=+DATA01/bys9/datafile/undotbs1.262.876770987
input datafile file number=00004 name=+DATA01/bys9/datafile/users.264.876771015
channel ORA_DISK_1: starting piece 1 at 12-MAY-15
channel ORA_DISK_1: finished piece 1 at 12-MAY-15
piece handle=/home/oracle/full_BYS9_20150512_2 tag=TAG20150512T225442 comment=NONE
channel ORA_DISK_1: backup set complete, elapsed time: 00:01:25
Finished backup at 12-MAY-15
Starting backup |