I just finished upgrading my AWS RDS database engine from 9.6.22 to 10.17. I used these steps to make the upgrade using the AWS Console:
Create snapshot of target database to upgrade
Restore snapshot
Upgrade the restored snapshot's (which is now a new instance) DB Engine version.
After I did all of this, everything seems fine but when I access the database, this warning message appears
WARNING: psql major version 9.6, server major version 10.
Some psql features might not work.
I want to know the meaning of this warning because I am fairly new in AWS as a whole.