Bcp Sync Using Rman

7/27/2019 Bcp Sync Using Rman

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Yahoo! White Paper

BCP Sync using RMAN IncrementalBackups

ByYahoo DBA Team


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Yahoo! White PaperBCP Sync using RMAN Incremental Backups

1.PurposeThis document explains the steps to sync up a BCP (Standby) with a primary database using

RMAN incremental backups.

2.Steps for BCP Sync using RMAN Incremental Backups

Oracle Recovery Manager (RMAN) is used to synchronize a BCP database with a primary

database by creating an incremental backup at the primary (source) database that always contain

the changed values in the blocks from the time it was created or cloned (refreshed). The

incremental backup is then applied to the BCP for keeping it up to date.

Incremental Backup using System Change Number (SCN) is the concept used to sync the

BCP with the primary.

Step 1: (Standby site)

From the standby that is lagging query the V$DATABASE view and record the current SCN.

SQL>column current_scn format 9999999999999

SQL> select current_scn from v$database;

Current_scn

------------------------------------

14218177179

Step 2: (Primary site)

Prepare command file to take incremental RMAN backup from primary.

Connect to the primary database as the RMAN target (RMAN target /) and create incremental

backup from the current SCN of the standby database recorded from the step 1 by means of

BACKUP INCREMENTAL FROM SCN=n (where n=number).

In the illustration the RMAN Backup location on source: /n01/rman_bkup


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Yahoo! White Paperrman_bkp.rcv:

=============

run

{

CONFIGURE DEVICE TYPE DISK PARALLELISM 16 BACKUP TYPE TO COMPRESSED

BACKUPSET;

backup as compressed backupset incremental from scn 14218177179 database filesperset=1

format ='/n01/rman_bkup/stex_%U';

}

The files that are backed up contains data blocks that were changed at SCNs greater than or

equal to SCN from step 1.


Start the backup

nohup rman target / cmdfile rman_bkp.rcv msglog rman_bkp.log &

RMAN backup took 80 min. for 11g fi les.


Use Netcat copy to copy the RMAN backups to the standby and also backup the control file to

the standby and note the location of the control files.

SQL> select name from v$contolfile;

On the Primary, create a new standby control file.

SQL> alter database create standby controlfile as '/tmp/standby.ctl';

Netcat copy took 45 min.


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Yahoo! White PaperStep 5: (Standby site)

1. Find out if the standby database is performing managed recovery.SQL> select process, status from v$managed_standby;

If the MRP process exists, then the standby database is performing managed recovery

2. Cancel the managed recovery process (MRP), stop redo apply on the standby database:

SQL> alter database recover managed standby database cancel;


Prepare recovery command file.

Connect to the standby database as RMAN target and apply incremental backups.

rman_reco.rcv:

==============

run

{

recover database noredo parallel 16;

}


Start the recovery

nohup rman target / cmdfile rman_reco.rcv msglog rman_reco.log &


Restore the standby control file.


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Yahoo! White Papercp -p /n01/oradata/STEXPAC2/standby_control01.ctl

/n01/oradata/STEXPAC2/standby_control01.ctl.bak

cp -p /n01/oradata/STEXPAC2/standby_control02.ctl

/n01/oradata/STEXPAC2/standby_control02.ctl.bak

cp -p standby.ctl /n01/oradata/STEXPAC2/standby_control01.ctl

cp -p standby.ctl /n01/oradata/STEXPAC2/standby_control02.ctl

RMAN apply took 80 mins


Start the managed recovery process:

SQL> alter database recover managed standby database disconnect from session;

Log apply services apply the archived redo logs to the standby database when the database is

performing managed recovery.

Step 9: (Primary and Standby site)

Check the SCNs in both Primary and BCP.

[Standby site] SQL> select current_scn from v$database;

CURRENT_SCN-----------1447474

[Primary site] SQL> select current_scn from v$database;

CURRENT_SCN-----------1447478


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Bcp Sync Using Rman