Oracle-DG,疑问，Duplicate在主库或者备库本地是否留下备份文件或者备份信息？

一、需求

某客户需要搭建dg,但是主库与备库剩余空间都不是很充足， 如果使用RMAN备份到本地，然后scp 备份文件到dg,空间需要考虑很多问题！

那么duplicate 方式搭建，是否会备份主库写到主库，或者写到备库的备份文件中呢？

本质上这个问题就是对duplicate操作的理解到什么程度！

二、观察duplicate日志

2.1 观察duplicate日志

Recovery Manager: Release 12.2.0.1.0 - Production on Tue Apr 20 06:38:37 2021

Copyright (c) 1982, 2017, Oracle and/or its affiliates.  All rights reserved.

connected to target database: ORCL (DBID=1594123398)
connected to auxiliary database: ORCL (not mounted)

RMAN> 2> 3> 4> 5> 6> 7> 8> 9> 10> 11>
using target database control file instead of recovery catalog
allocated channel: p1
channel p1: SID=75 device type=DISK

allocated channel: p2
channel p2: SID=76 device type=DISK

allocated channel: p3
channel p3: SID=77 device type=DISK

allocated channel: p4
channel p4: SID=78 device type=DISK

allocated channel: s1
channel s1: SID=35 device type=DISK

allocated channel: s2
channel s2: SID=36 device type=DISK

allocated channel: s3
channel s3: SID=37 device type=DISK

allocated channel: s4
channel s4: SID=38 device type=DISK

Starting Duplicate Db at 20-APR-21

contents of Memory Script:
{
   backup as copy reuse
   targetfile  '/picclife/app/oracle/product/12.2.0/db_1/dbs/orapwc11' auxiliary format
 '/picclife/app/oracle/product/12.2.0/db_1/dbs/orapwc12'   ;
}
executing Memory Script

Starting backup at 20-APR-21
Finished backup at 20-APR-21

contents of Memory Script:
{
   restore clone from service  'tns_pri' standby controlfile;
}
executing Memory Script

Starting restore at 20-APR-21

channel s1: starting datafile backup set restore
channel s1: using network backup set from service tns_pri
channel s1: restoring control file
channel s1: restore complete, elapsed time: 00:00:04
output file name=/picclife/app/oracle/oradata/orcldg/control01.ctl
output file name=/picclife/app/oracle/oradata/orcldg/control02.ctl
Finished restore at 20-APR-21

contents of Memory Script:
{
   sql clone 'alter database mount standby database';
}
executing Memory Script

sql statement: alter database mount standby database

contents of Memory Script:
{
   set newname for tempfile  1 to
 "/picclife/app/oracle/oradata/orcldg/temp01.dbf";
   set newname for tempfile  2 to
 "/picclife/app/oracle/oradata/orcldg/pdbseeddg/temp012021-03-04_22-18-29-699-PM.dbf";
   set newname for tempfile  3 to
 "/picclife/app/oracle/oradata/orcldg/c11pdbdg/temp01.dbf";
   switch clone tempfile all;
   set newname for datafile  1 to
 "/picclife/app/oracle/oradata/orcldg/system01.dbf";
   set newname for datafile  3 to
 "/picclife/app/oracle/oradata/orcldg/sysaux01.dbf";
   set newname for datafile  4 to
 "/picclife/app/oracle/oradata/orcldg/undotbs01.dbf";
   set newname for datafile  5 to
 "/picclife/app/oracle/oradata/orcldg/pdbseeddg/system01.dbf";
   set newname for datafile  6 to
 "/picclife/app/oracle/oradata/orcldg/pdbseeddg/sysaux01.dbf";
   set newname for datafile  7 to
 "/picclife/app/oracle/oradata/orcldg/users01.dbf";
   set newname for datafile  8 to
 "/picclife/app/oracle/oradata/orcldg/pdbseeddg/undotbs01.dbf";
   set newname for datafile  9 to
 "/picclife/app/oracle/oradata/orcldg/c11pdbdg/system01.dbf";
   set newname for datafile  10 to
 "/picclife/app/oracle/oradata/orcldg/c11pdbdg/sysaux01.dbf";
   set newname for datafile  11 to
 "/picclife/app/oracle/oradata/orcldg/c11pdbdg/undotbs01.dbf";
   set newname for datafile  12 to
 "/picclife/app/oracle/oradata/orcldg/c11pdbdg/users01.dbf";
   restore
   from  nonsparse   from service
 'tns_pri'   clone database
   ;
   sql 'alter system archive log current';
}
executing Memory Script

executing command: SET NEWNAME

executing command: SET NEWNAME

executing command: SET NEWNAME

renamed tempfile 1 to /picclife/app/oracle/oradata/orcldg/temp01.dbf in control file
renamed tempfile 2 to /picclife/app/oracle/oradata/orcldg/pdbseeddg/temp012021-03-04_22-18-29-699-PM.dbf in control file
renamed tempfile 3 to /picclife/app/oracle/oradata/orcldg/c11pdbdg/temp01.dbf in control file

executing command: SET NEWNAME

executing command: SET NEWNAME

executing command: SET NEWNAME

executing command: SET NEWNAME

executing command: SET NEWNAME

executing command: SET NEWNAME

executing command: SET NEWNAME

executing command: SET NEWNAME

executing command: SET NEWNAME

executing command: SET NEWNAME

executing command: SET NEWNAME

Starting restore at 20-APR-21

skipping datafile 5; already restored to SCN 1447512
skipping datafile 6; already restored to SCN 1447512
skipping datafile 8; already restored to SCN 1447512
channel s1: starting datafile backup set restore
channel s1: using network backup set from service tns_pri
channel s1: specifying datafile(s) to restore from backup set
channel s1: restoring datafile 00001 to /picclife/app/oracle/oradata/orcldg/system01.dbf
channel s2: starting datafile backup set restore
channel s2: using network backup set from service tns_pri
channel s2: specifying datafile(s) to restore from backup set
channel s2: restoring datafile 00003 to /picclife/app/oracle/oradata/orcldg/sysaux01.dbf
channel s3: starting datafile backup set restore
channel s3: using network backup set from service tns_pri
channel s3: specifying datafile(s) to restore from backup set
channel s3: restoring datafile 00004 to /picclife/app/oracle/oradata/orcldg/undotbs01.dbf
channel s4: starting datafile backup set restore
channel s4: using network backup set from service tns_pri
channel s4: specifying datafile(s) to restore from backup set
channel s4: restoring datafile 00007 to /picclife/app/oracle/oradata/orcldg/users01.dbf
channel s4: restore complete, elapsed time: 00:00:17
channel s4: starting datafile backup set restore
channel s4: using network backup set from service tns_pri
channel s4: specifying datafile(s) to restore from backup set
channel s4: restoring datafile 00009 to /picclife/app/oracle/oradata/orcldg/c11pdbdg/system01.dbf
channel s3: restore complete, elapsed time: 00:01:04
channel s3: starting datafile backup set restore
channel s3: using network backup set from service tns_pri
channel s3: specifying datafile(s) to restore from backup set
channel s3: restoring datafile 00010 to /picclife/app/oracle/oradata/orcldg/c11pdbdg/sysaux01.dbf
channel s4: restore complete, elapsed time: 00:00:55
channel s4: starting datafile backup set restore
channel s4: using network backup set from service tns_pri
channel s4: specifying datafile(s) to restore from backup set
channel s4: restoring datafile 00011 to /picclife/app/oracle/oradata/orcldg/c11pdbdg/undotbs01.dbf
channel s4: restore complete, elapsed time: 00:00:20
channel s4: starting datafile backup set restore
channel s4: using network backup set from service tns_pri
channel s4: specifying datafile(s) to restore from backup set
channel s4: restoring datafile 00012 to /picclife/app/oracle/oradata/orcldg/c11pdbdg/users01.dbf
channel s2: restore complete, elapsed time: 00:01:38
channel s4: restore complete, elapsed time: 00:00:07
channel s1: restore complete, elapsed time: 00:01:53
channel s3: restore complete, elapsed time: 00:00:47
Finished restore at 20-APR-21

sql statement: alter system archive log current

contents of Memory Script:
{
   switch clone datafile all;
}
executing Memory Script

datafile 1 switched to datafile copy
input datafile copy RECID=4 STAMP=1070347457 file name=/picclife/app/oracle/oradata/orcldg/system01.dbf
datafile 3 switched to datafile copy
input datafile copy RECID=5 STAMP=1070347457 file name=/picclife/app/oracle/oradata/orcldg/sysaux01.dbf
datafile 4 switched to datafile copy
input datafile copy RECID=6 STAMP=1070347457 file name=/picclife/app/oracle/oradata/orcldg/undotbs01.dbf
datafile 5 switched to datafile copy
input datafile copy RECID=7 STAMP=1070347457 file name=/picclife/app/oracle/oradata/orcldg/pdbseeddg/system01.dbf
datafile 6 switched to datafile copy
input datafile copy RECID=8 STAMP=1070347457 file name=/picclife/app/oracle/oradata/orcldg/pdbseeddg/sysaux01.dbf
datafile 7 switched to datafile copy
input datafile copy RECID=9 STAMP=1070347457 file name=/picclife/app/oracle/oradata/orcldg/users01.dbf
datafile 8 switched to datafile copy
input datafile copy RECID=10 STAMP=1070347457 file name=/picclife/app/oracle/oradata/orcldg/pdbseeddg/undotbs01.dbf
datafile 9 switched to datafile copy
input datafile copy RECID=11 STAMP=1070347457 file name=/picclife/app/oracle/oradata/orcldg/c11pdbdg/system01.dbf
datafile 10 switched to datafile copy
input datafile copy RECID=12 STAMP=1070347457 file name=/picclife/app/oracle/oradata/orcldg/c11pdbdg/sysaux01.dbf
datafile 11 switched to datafile copy
input datafile copy RECID=13 STAMP=1070347457 file name=/picclife/app/oracle/oradata/orcldg/c11pdbdg/undotbs01.dbf
datafile 12 switched to datafile copy
input datafile copy RECID=14 STAMP=1070347457 file name=/picclife/app/oracle/oradata/orcldg/c11pdbdg/users01.dbf
Finished Duplicate Db at 20-APR-21
released channel: p1
released channel: p2
released channel: p3
released channel: p4
released channel: s1
released channel: s2
released channel: s3
released channel: s4

RMAN>

可以看到对于duplicate产生的日志：
1.连接主备，分配RMAN备份通道；
2.将主库口令文件 scp 到dg;
3.主库备份standby controlfile ->scp dg-> dg 启动到mount;
4.根据参数convert 转换文件路径；
5.主库在线进行copy datafile ->scp dg 
6.结束!  如果是生产环境，会scp ->archive 

2.2 主备检查备份

Primary
RMAN> list backup of datafile 1;
using target database control file instead of recovery catalog
specification does not match any backup in the repository
list backup 出现一堆乱七八糟的信息太多，全备肯定会存在datafile 1的备份信息

Standby
RMAN> list backup of datafile 1;
using target database control file instead of recovery catalog
specification does not match any backup in the repository

所以，在主备本地空间不是很充足的情况下，可以使用duplicate,这样不在需要考虑rman备份文件的存储空间占用。