In this post, we will see in details the steps to upgrade your AWS Oracle RDS.
Here we are upgrading our Oracle database from 12c to 19c.
Upgrades are majorly of 2 types :
- Major Version Upgrade
Major Version Upgrade arent applied automatically by AWS and this need a manual intervention, since the changes introduced may not be compatible with your existing Applications
- Minor Version Upgrade
If you enable auto minor version upgrades on your DB instance, minor version upgrades occur automatically.
You need to ensure that the Application Team is aware of the Scheduled Maintenance Window of your Minor Version Upgrade, since AWS sometimes doesnt notify priorly for the DB Minor Version Upgrade.
The steps followed here are more or less same for every DB engines.
We need to know the theoretical part before proceeding with the practical session of the blog. Please refer to the below link from AWS for the theoretical part :
Let us proceed with the pratical session
1. You need to check the Option Groups and Parameter Groups before proceeding with the upgrade.
If your database is using Default Option and Parameter groups, you need not worry and proceed with your upgrade. If they are using Custom Option/Parameter groups, you need to create the same compatible with the new version and attach them to the database after upgrade by modifying your instance.
In this session, we are using Default Option/Parameter groups
2. If automatic backups arent enabled, please ensure to take a snapshot of your database before proceeding with the change. If automatic backups are enabled, AWS will automatically take a backup of your database before upgrading
You can verify whether your databases automatic backups are enabled or not, by checking on the Backup-retention period. If the Backup Retention Period is greater than 0, then Automatic Backups are enabled for your database
3. Login to your database and execute Stats Gather
4. Now to upgrade your database engine, click on your database –> Modify
5. Change the DB Engine Version to 19c
6. Click on Apply Immediately if you are planning to upgrade the database instantly, or else Click the other option to upgrade during the next scheduled Maintenance Window and Modify DB Instance
7. Once you click on Modify DB Instance, a snapshot of your Database instance will be taken (if Backup retention period is more than 0 days), and then the Database will be upgraded
NOTE : Once the database is upgraded, it wont be possible to revert back the changes. If you need the Older version of your database, you need to manually restore it from the snapshot. The DB Snapshot is taken before and after the upgrade activity.
8. Once the DB is upgraded, you can change the default parameter/option groups with the custom parameter/option groups compatible with the newer version by modifying the instance
For more videos and posts, refer to the below links :