Force_logging is not enabled in standbny system..any suggestion what to do?

[Former Member]

Dear Experts,

I Need to carry out Disaster Recovery Test( By Bringing up the SAP application on the standby system host) for BW system. As part of precheckes I just checked for the force_logging option,both in production and the standby systems. In production system force_logging option was set to Yes where as in standby system its set to NO.

As per my knowledge, we will not be able to run any query on the standby host as the force_logging option was set to NO in the standby system. Any suggestion how to fix this issue now ? Do I need to rebuild entire standby system again after enabling the force_logging option in the standby system also.

Note: There were many indexes,tables have been created in the production system with force_logging option set to yes and builted the standby system without enabling the force_loggin option.

Appriciate your response on this. It would be helpful for me if you can provide any doc or link to get aware about the force_loggin option and the use of it .

Thanks & Regards

Rajesh Meda

[stefan_koehler · Accepted solution]

Hello Rajesh,

the oracle documentation will answer your question:

http://download.oracle.com/docs/cd/B19306_01/server.102/b25159/configbp.htm#CHDDHBHC

> As per my knowledge, we will not be able to run any query on the standby host as the force_logging option was set to NO in the standby system

The FORCE LOGGING option is important for the production system and not in the standby system itself. If you enable FORCE LOGGING on the production site you will get all the corresponding redo log entries. So if you recover the redo log / archive log files on your standby site you got all what you need.

Just check the documentation - it describes it very well.

Regards

Stefan

[Former Member · Accepted solution]

Thanks for your reply...

Correct me If I am wrong...actually as suggested in that link, we need to identify the

data files that are affected and need to recreate the standby system as described in the secion 9.4.6. Would you please let me know how to find out the affected data files.

and one more thing ...I will cleanup entire standby system and will build the system from scratch..what do you say ?

1.Clean up the current hot stand by system

2.Enable the force_logging option in the standby system

3.Restore the Production db from consistent backup

4.Bring the standby system in Sync with Production

If you are suggesting to go for identifying the affected data files and then do perform the necessary actions, can you specify the sequence of steps please.

Thanks & Regards

Rajesh Meda

[stefan_koehler · Accepted solution]

Hello Rajesh,

> actually as suggested in that link, we need to identify the data files that are affected and need to recreate the standby system as described in the secion 9.4.6

No you are wrong. The documentation says "When the production database is in FORCE LOGGING mode, all database data changes are logged. FORCE LOGGING mode ensures that the standby database remains consistent with the production database.", so there is no need to copy any data files if you have enabled FORCE LOGGING on the production site.

If you have enabled FORCE LOGGING after the standby creation i would build up the standby database again.

Regards

Stefan

[Former Member · Accepted solution]

Hi Stefan,

My standby database was already in place when "Force logging" was not enabled at Primary.

Now, if I enable it on Primary database will there be an issue or standby will continue like before.

I am unable to get an approval for standby re-build so wanted to know the impact.

Regards,

Pallavi.