RE: RMAN duplicate RAC to single instance - how to not duplicate redo threads and temp tablespace

  • From: Don Granaman <DonGranaman@xxxxxxxxxxxxxxx>
  • To: "campbell.neil@xxxxxxxxxxx" <campbell.neil@xxxxxxxxxxx>, Oracle List <oracle-l@xxxxxxxxxxxxx>
  • Date: Thu, 29 Mar 2012 13:54:12 -0500

I do this all the time.  Obviously, you cannot "skip" the redo or undo for any 
instance and still perform recovery, but you can duplicate the database and 
when it is done do (for a two-instance RAC database clone to an exclusive 

alter database disable thread 2;
alter database drop logfile group 7;
alter database drop logfile group 8;
drop tablespace UNDOTBS2 including contents and datafiles;
(Modify as appropriate for your system, redo logs and undo tablespaces.)

For the temp tablespace, I haven't tried the other suggestions, but I just do 
something akin to (using Oracle-managed files):
create temporary tablespace tmptmp tempfile size 100M;
alter database default temporary tablespace TMPTMP;
drop tablespace TEMP including contents and datafiles;
create temporary tablespace TEMP tempfile size 1024M;
alter database default temporary tablespace TEMP;
drop tablespace TMPTMP including contents and datafiles;

Of course there are other options...

Don Granaman | Phone: 402-361-3073 | Cell: 402-960-6955 | Fax: 402-361-3173 | 
Solutionary | Relevant . Intelligent . Security

-----Original Message-----
From: oracle-l-bounce@xxxxxxxxxxxxx [mailto:oracle-l-bounce@xxxxxxxxxxxxx] On 
Behalf Of neil campbell
Sent: Wednesday, March 28, 2012 12:01 AM
To: Oracle List
Subject: RMAN duplicate RAC to single instance - how to not duplicate redo 
threads and temp tablspace

Hi all,

Using and trying to work out if I can do an RMAN duplicate from 4 node 
RAC to single instance without
the duplicate generating the 4 threads of redo?

Also, I wondered if it was possible to have the duplicate NOT create the TEMP 
tablespace as part of the duplicate?

I am running the duplicate as part of an automated script, and it is a simple 
statement as follows

     duplicate database PROD to TEST pfile='/u01/app/oracle/test/pfile.test' 
backup location='/orabackup'

This works very well, but the reason behind the requirement to not create 
additional threads and TEMP tablespace is the limited amount of space
in the TEST environment at the moment. Removing the threads and TEMP tablespace 
would free up 48 Gb as the 
test environment doesn't run the batch jobs that use all that TEMP space.

Open to suggestions...



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