Downgrade database to earlier version is it possible?

[Former Member]

Hi All,

We are planning to upgrade our database from 10.1.0.4 to 10.2.0.2 on our SRM server. ( it is an upgrade and not just patch set application )

Can anybody guide for any fallback plan that should we go for?

i.e. if due to any problem we want to downgrade our database to earlier version, what procedure should be followed.

Will database upgrade make any changes to our data files?

If I take offline backup of database using brtools, will I be able to restore it on the newer version of databse?

Or should we go for NT level Backup ( file system backup ) if yes...What file systems should be included.

Thanks.

Regards,

Shamish

[former_member204746 · Accepted solution]

obviously, backup your system before attempting your upgrade.

this means that you upgrade your database, but also do an OS backup of all other files not taken by BRBACKUP.

this way, you will be able to completely restore your system to point before upgrade.

Good luck.

[Former Member]

Dear Shamish Lele,

Downgrade is not possible once you do upgrade of your database.

Before doing upgrade take backup of Database so in case you want to come back to old stage you can have option to restore old database thats only possibility.

Regards,

Nikunj

[stefan_koehler]

Hello Shamish,

> Can anybody guide for any fallback plan that should we go for?

At first you should know that a downgrade is only possible, if you have done everything correct (especially with the parameter COMPATIBLE - sapnote #598470). For oracle information about COMPATIBLE - take a look here:

http://download.oracle.com/docs/cd/B19306_01/server.102/b14238/compat.htm#i1014069

The downgrade procedure is described here:

http://download.oracle.com/docs/cd/B19306_01/server.102/b14238/downgrade.htm#CACGBHDB

> Will database upgrade make any changes to our data files?

Of course, it make changes to your data files. If you set the correct COMPATIBLE only the content will be changed, if the COMPATIBLE is set to the upgraded version, the "logical" structure can / is be changed, too.

> If I take offline backup of database using brtools, will I be able to restore it on the newer version of databse?

No, if you try to open a database that was created on 10.1.x with a 10.2.x installation, you will get an error and have to run the upgrade on the database again (STARTUP UPGRADE).

> Or should we go for NT level Backup ( file system backup ) if yes...What file systems should be included.

All oracle directories.

Regards

Stefan