PLANNED FAILOVER and ReIntializing the OLD Primary as the NEW Standby(Using Flashback)

UNPLANNED FAILOVER and ReInitializing the OLD Primary as the NEW Standby(Using Flashback).

failover is done when the primary database (all instances of an Oracle RAC primary database) fails or has become unreachable and one of the standby databases is transitioned to take over the primary role. Failover should be performed when the primary database cannot be recovered in a timely manner. Failover may or may not result in data loss depending on the protection mode in effect at the time of the failover.

–> In this article, I will explain when we unplanned for failover, In that case how to build standby database from old primary database using Flashback concept.

Primary –> prod(dba12)

Standby –>stand(dba13)

Primary Side:(dba12)

Check the information Primary  database and max log applied.

Standby Side: (dba13)

Check the information standby database and logs are syncing with primary  or not.

Stop the managed recovery at standby side.

Primary Side: (dba12)

Create a guaranteed Restore point on current PRIMARY DATABASE.

Verify physical standby databases are current

Standby Side: (dba13)

Activate standby by using following syntax.

NEW_PRIMARY SIDE :(dba13)

Shutdown new primary database and keep in state and obtain the SCN  from the new primary

Check if the remote archive destinations are in “DEFER” state.

OLD_PRIMARY SIDE :(dba12)

Flash back the old primary to SCN captured. but before doing flashback OLD_PRIMARY should be in mount state.

Once we done with flashback the database can’t become Physical standby . we need to manually.

NEW_PRIMARY SIDE :(dba13)

Give few log switches.

OLD_PRIMARY SIDE :(dba12)

Check logs are reflected and applied are not.

Now archives are reaching to standby side.

So,enable MANAGED RECOVERY mode at standby side.

NOTE :

Here we converted  the PRIMARY as STANDBY and STANDBY as PRIMARY.

Just try with opposite by following same steps.

 

 THANK YOU

 

 

 

Note: Please test scripts in Non Prod before trying in Production.
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