Validate the upgrade process
After a few minutes you will see that the database already finished the upgrade process and the status will be back to Available.
Click on the instance, then the Configuration tab and you will see that the database engine version went from 15.3 to 15.4.
Or if you rather use the CLI command, type in the console:
aws rds describe-db-instances --db-instance-identifier < your database name > --region < your region > --query DBInstances[*].EngineVersion
You can see engine version after run command above:
