Moving from 8.3 to 8.4
The client system was recently upgraded to Pega 831.
As Pega 8.4 is out now, what does it take to upgrade/update the version?
Is there a delta portion (like a patch), which can be considered for swift movement. Or the entire process of upgrading a system will be the way to go; including re-running the upgrade jobs, re-deploying the war, and any post-upgrade changes that would follow.