Protection for issues after upgrade
In this part you’ll use again two techniques to protect your database, but this time for issues happening after the upgrade. You can call this also “Downgrade“.
1. Downgrade with a Full Database Export and Import
For this part you’ll just start the export from the 18c database after upgrading.
- Run the full database export:
The important part is that the
VERSIONparameter tells Data Pump to create an export in the format a database of “VERSION” will understand.
- In this case you will downgrade into a 12.1 Pluggable Database. You need to create the PDB first.
This was a quick exercise. Of course it would take longer the more data and objects your database contains. Especially LOB data types can be crucial.
2. Downgrade with the downgrade scripts
In this final exercise you’ll use a powerful technique, the database downgrade with downgrade scripts.
- Set a marker in the database
- Run the downgrade script
- Switch to the source environment and start he bootstrap reload script
- Final steps and checks
The downgrade should have removed the XDB component as well. Did it?
You can watch an entire database downgrade in this short video as well:
Congratulations. You completed all 4 steps of the Fallback Strategies Hands-On Lab.
Feel free to upgrade again!