Convert RAC Physical Standby To Snapshot Standby in RAC enviroment

 

 

Convert RAC Physical Standby To Snapshot Standby in RAC enviroment

 Current : Standby Database with 4 node RAC enviroment

Step1 :-  Pre-requiste   

•  FRA needs to be configured.
•  Ensure the  ORL  path exist  (Online redo logs are created)

Show parameter db_recovery_files_dest

Show parameter db_recovery_file_dest_size

 

To Check if ORL (Online redo log path exist)

 

SELECT thread#, group#, sequence#, bytes, archived ,l.status, blocksize, member FROM v$log l join v$logfile f using (GROUP#) ORDER BY thread#, group#;

Step 2 :- Once FRA is configured and redo log created on Standby

Stop the db using srvctl command on standby

 srvctl stop database -d ORCLDR -o immediate

Startup db in mount stage

srvctl start database -d ORCLDR -o mount

srvctl status database -d ORCLDR

Confirm its mounted.                                                   

Step 3 : Connect to sqlplus and enable flashback

Creation of guarantee restore point instead of normal restore point

alter system set db_flashback_retention_target=1440;

create restore point before_snapshot_19c guarantee flashback database;

select scn, storage_size, time, name from v$restore_point;

or

Connect /as sysdba

Select status from v$instance;

Ensure it shows Mounted

alter database flashback on;

Alter system set db_flashback_retention_target=<value> scope=both sid='*' ;

Select flashback_on from v$database ;

Select * from v$flash_recovery_area_size ;

Select * from v$restore_point ;

 

 

Step 4 :- Shutdown the db and startup in mount stage

srvctl stop database -d ORCLDR -o immediate

srvctl status database -d ORCLDR

 

srvctl start database -d ORCLDR -o mount

srvctl status database -d ORCLDR

Ensure the instance is mounted

Step 5 :- Connect to sqlplus and convert to Snapshot standby

Connect /as sysdba

Select status from v$instance ; ===> Should show Mounted


Alter database convert to Snapshot standby ;

Alter database open ;

Once done

Select database_role,controlfile_type from v$database ;

 

Step 6 :- Restart the entire db if required

srvctl stop database -d ORCLDR -o immediate

srvctl status database -d ORCLDR

Start the db (Both instance using srvctl)

srvctl start database -d ORCLDR -o open

 

 

------------------Revert Back---------------------------

##once app testing is completed and confirmed by apps team

##shutdown DR , restart it in mount stage and convert to physical standby

                      

srvctl stop database -d ORCLDR -o immediate

srvctl start database -d ORCLDR -o mount

 

alter database convert to physical standby;

 

srvctl stop database -d ORCLDR -o immediate

srvctl start database -d ORCLDR 

 

ALTER DATABASE RECOVER MANAGED STANDBY DATABASE DISCONNECT FROM SESSION.

 

alter database flashback off;

or

drop RESTORE POINT before_snapshot_19c;

 

Monitor DC -DR sync progress.