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Roll Forward Physical Standby

Typically, when rolling forward a physical standby database using primary incremental backup, multiple steps are required:

  1. Identify the Start SCN on Standby for performing incremental backup on primary
  2. Perform incremental backup on primary with FROM SCN clause
  3. Move the backup-pieces from primary to standby
  4. Catalog the backup-piece on Standby
  5. Perform recovery on standby using recover database noredo
  6. Refresh standby controlfile again from primary

Starting from 12.1, we could use “RECOVER DATABASE FROM SERVICE”command which will automate a few steps like performing incremental backup on primary, transfer the backup-pieces to standby over network and perform recovery on standby. However, we still had to manually refresh the standby controlfile and manually restore newly-added datafiles. These steps required manual efforts and are error prone especially when standby files are physically located in a path different to that of primary.

Starting with 18.1, we can use a single command to refresh the standby with changes made on primary:

RMAN> RECOVER STANDBY DATABASE FROM SERVICE primary_connect_identifier;

This command will internally keep track of standby file locations, refresh standby controlfile from primary, update the new standby controlfile with standby file names, perform incremental backup on primary, transfer the backup-pieces over network to standby and perform recovery on standby

1. To refresh the standby, ensure that managed recovery is stopped on standby:

SQL> recover managed standby database cancel;

NOTE: If you do not stop managed recovery, you will get RMAN-05150 error during execution:

RMAN> RECOVER STANDBY DATABASE FROM SERVICE PRM180;
RMAN-03090: Starting recover at 03-AUG-18
RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-03002: failure of recover command at 08/03/2018 12:33:05
RMAN-05150: Managed Recovery Process must be disabled before running RECOVER STANDBY DATABASE.

2. Ensure that Oracle Net connectivity is established between the physical standby database and the primary database by adding an entry corresponding to the primary database in the tnsnames.ora file of the physical standby database. In below example, PRM180 is the connect identifier for primary.

3. Connect RMAN to standby as target and run “RECOVER STANDBY DATABASE FROM SERVICE” command. Find below an example run for the command:

[oracle@ora18DbSrv ~]$ export ORACLE_SID=SBY180
[oracle@ora18DbSrv ~]$ rman target /

RMAN> RECOVER STANDBY DATABASE FROM SERVICE PRM180;

RMAN-03090: Starting recover at 03-AUG-18
RMAN-06009: using target database control file instead of recovery catalog
RMAN-06196: Oracle instance started

Total System Global Area 671086904 bytes

Fixed Size 8661304 bytes
Variable Size 188743680 bytes
Database Buffers 465567744 bytes
Redo Buffers 8114176 bytes

RMAN-08161: contents of Memory Script:
{
restore standby controlfile from service ‘PRM180’;
alter database mount standby database;
}
RMAN-08162: executing Memory Script

RMAN-03090: Starting restore at 03-AUG-18
RMAN-08030: allocated channel: ORA_DISK_1
RMAN-08500: channel ORA_DISK_1: SID=141 device type=DISK

RMAN-08016: channel ORA_DISK_1: starting datafile backup set restore
RMAN-08169: channel ORA_DISK_1: using network backup set from service PRM180
RMAN-08021: channel ORA_DISK_1: restoring control file
RMAN-08180: channel ORA_DISK_1: restore complete, elapsed time: 00:00:01
RMAN-08505: output file name=/u01/app/oracle/oradata/SBY180/control01.ctl
RMAN-03091: Finished restore at 03-AUG-18

RMAN-08031: released channel: ORA_DISK_1
RMAN-06986: Statement processed
RMAN-06958: Executing: alter system set standby_file_management=manual

RMAN-08161: contents of Memory Script:
{
recover database from service ‘PRM180’;
}
RMAN-08162: executing Memory Script

RMAN-03090: Starting recover at 03-AUG-18
RMAN-08030: allocated channel: ORA_DISK_1
RMAN-08500: channel ORA_DISK_1: SID=149 device type=DISK
RMAN-06179: datafile 4 not processed because file is read-only
RMAN-08039: channel ORA_DISK_1: starting incremental datafile backup set restore
RMAN-08169: channel ORA_DISK_1: using network backup set from service PRM180
RMAN-08509: destination for restore of datafile 00001: /u01/app/oracle/oradata/SBY180/system01.dbf
RMAN-08180: channel ORA_DISK_1: restore complete, elapsed time: 00:00:03
RMAN-08039: channel ORA_DISK_1: starting incremental datafile backup set restore
RMAN-08169: channel ORA_DISK_1: using network backup set from service PRM180
RMAN-08509: destination for restore of datafile 00002: /u01/app/oracle/oradata/SBY180/sysaux01.dbf
RMAN-08180: channel ORA_DISK_1: restore complete, elapsed time: 00:00:07
RMAN-08039: channel ORA_DISK_1: starting incremental datafile backup set restore
RMAN-08169: channel ORA_DISK_1: using network backup set from service PRM180
RMAN-08509: destination for restore of datafile 00003: /u01/app/oracle/oradata/SBY180/undotbs01.dbf
RMAN-08180: channel ORA_DISK_1: restore complete, elapsed time: 00:00:03

RMAN-08054: starting media recovery

RMAN-08181: media recovery complete, elapsed time: 00:00:00
RMAN-03091: Finished recover at 03-AUG-18
RMAN-06958: Executing: alter system set standby_file_management=auto
RMAN-03091: Finished recover at 03-AUG-18

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