A reader asked me for advice on upgrading Oracle Database and replacing the underlying operating system.

• Currently on Oracle Database 12.1.0.2
• Currently on Windows Server 2012
• Upgrade to Oracle Database 19c
• Move to new servers with Microsoft Windows Server 2022

What’s the recommended approach for transitioning to Oracle 19c on Windows 2022?

Oracle Data Guard

My first option is always Oracle Data Guard. It is often a superior option. You move the entire database, and the only interruption is a Data Guard switchover.

In this case, where the reader needs to replace the operating system, the first thing to check is platform certifications. Always check platform certifications on My Oracle Support. It has the most up-to-date information.

Here is an overview of the platform certification for Oracle Database 12.1.0.2 and 19c.

Oracle Database 12.1.0.2	Oracle Database 19c
Windows Server 2008
Windows Server 2008 R2
Windows Server 2012
Windows Server 2012 R2	Windows Server 2012 R2
	Windows Server 2016
	Windows Server 2019
	Windows Server 2022

Oracle Database 19c does not support the current platform, Windows Server 2012. Thus, the reader can’t set up a standby database on the new servers and transition via a regular switchover.

Windows Server 2012 R2

Let’s imagine the current servers were using Windows Server 2012 R2. Both database releases support this platform. I would recommend this approach:

1. Upgrade to Oracle Database 19c on current servers.
2. Set up new servers with Windows Server 2022.
3. Create standby database on new server.
4. Transition to new servers with a regular Data Guard switchver.

This approach requires two maintenance windows. Yet, it is still my favorite because it is very simple.

RMAN Backups

You could also use RMAN and incremental backups. You don’t need much downtime – just the time necessary for a final incremental backup and restore. Like with Data Guard, you bring over the entire database.

RMAN can restore backups from a previous version, and you can use that to your advantage.

1. Provision new servers with just Oracle Database 19c.
2. Backup on 12.1.0.2.
3. Restore and recover the database on the new servers with Oracle Database 19c binaries.
4. After the final incremental backup, open the new database in upgrade mode and perform the upgrade.

We covered this approach in one of our webinars; you can also find details in this blog post.

Move Storage

You can also unmount the storage from the old server, and attach it to the new server.

1. Run AutoUpgrade in analyze mode to determine upgrade readiness.
2. Down time starts.
3. Run AutoUpgrade in fixup mode to fix any issues preventing the upgrade from starting.
4. Cleanly shut down the source database.
5. Move the storage to the new server.
6. Start the database on the new server in upgrade mode.
7. Start AutoUpgrade in upgrade mode to complete the upgrade.

This is just a high-level overview. For a real move, there are many more intermediate steps.

Be sure to have a proper rollback plan. You are re-using the data files and AutoUprade in upgrade mode does not create a guaranteed restore point.

Data Pump

Data Pump is also a viable option, especially for smaller, less complex databases. It also enables you to restructure your database, for example:

• Transform old BasicFile LOBs to SecureFile
• Implement partitioning
• Exclude data (for archival)
• You can import directly into a higher release and even directly into a PDB.

But – the larger the database, the longer downtime (generally speaking).

When you use Data Pump for upgrades, I recommend using a full database export.

Full Transportable Export/Import

You can also use transportable tablespaces for upgrades. You can even migrate directly into a PDB on Oracle Database 19c.

The downside of transportable tablespace is that you must copy the data files to the new system.

But often, you can unmount the storage and mount the storage on the new servers. This avoids the cumbersome process of copying the data files to the new system.

Another approach is to combine transportable tablespaces with incremental backups, if you want to lower the downtime needed. This approach leaves the original database untouched, leaving you with a perfect rollback option.

Oracle GoldenGate

You could also use Oracle GoldenGate. But for most upgrades, it is overkill, partly because of the restrictions and considerations. I see this as a sensible option only if you have very strict downtime or fallback requirements.

Conclusion

What is the best option?

It depends…

This post helps you make the best decision for your organization.