In this Document

Applies to:

Goal

Rman 11g release 2 provides us the flexibility of creating the rman duplicate without connecting to the target database and recovery catalog.

All rman needs here is the location of the backup pieces which is accessible and rman reads the backup pieces and restores the spfile,controlfile,datafiles and archivelog files to perform the duplicate operation.

An example for this kind of duplicate operation is:

RMAN> DUPLICATE DATABASE TO dup11r2
                UNTIL TIME "TO_DATE('29-MAY-2010 14:16:42','DD-MON-YYYYHH24:MI:SS')"
                SPFILE
                 set control_files='D:\dup11r2\c1.ctl'
                 set db_file_name_convert='D:\Database\Ora11g2\ora11g2','d:\dup11r2'
                 set log_file_name_convert='D:\Database\Ora11g2\ora11g2','d:\dup11r2'
               BACKUP LOCATION 'D:\dup11r2';

# Here use of the BACKUP LOCATION clause identifies the type of duplication as having no target connection, no recovery catalog and being backup-based.

Solution

Process involved in this type of duplicate database

++ Rman restores the spfile from the backup pieces located in the mentioned location.

++ Once the spfile is restored, rman sets appropriate values to the parameters mentioned the duplicate command. For example:

db_name
control_files
db_file_name_convert
log_file_name_convert

etc ...

Once done, rman restarts the instance to no mount so that the changes can take effect.

++ Rman now changes the value of the parameter db_name to the target database name to achieve the restore of the controlfile. The restored controlfile will have the db_name as of the target database name and since we cannot have a different db_name in the spfile and in the controlfile, rman will have to set the parameter db_name to the target database name and perform the restore of the datafiles and controlfiles.

Also here if the duplicate is happening on the same machine, then 2 controlfiles with the same db_name cannot be mounted. In order to achieve this the auxiliary instance will have the parameter db_unique_name set to a unique value. Rman takes care of this sets the db_uniqiue_name to the database name specified for the auxiliary database.

++ After the above operation,controlfile is restored from the backup piece to the location provided for the parameter control_files.

++ Now Rman restores the datafiles to the locations specified by the parameter log_file_name_convert.

++ Recovery of the datafiles are performed.

++ Once the recovery is completed, rman shuts down the database to reset the value of db_name to the value provided for the auxiliary database.

++ Once this is done, the database is taken to no mount phase and the controlfile is recreated to change the database name and the id.This is followed by the database getting opened with resetlogs.

The steps involved in creating the duplicate database are as follows

1) Take a backup of the spfile, controlfile, database, and archivelogs as follows:

2) Making the backup pieces available for duplicate operation.

3) Create a password file for the auxiliary instance.

4) Create a initialization parameter for the auxiliary instance with only one parameter DB_NAME.

5) Now start the auxiliary instance to no mount mode.

6) Connect to the auxiliary instance from RMAN and perform the rman duplicate as follows: