Download App Updates
Make sure you update the applications, both first and third-party, on your Galaxy Note 9 before you download Android Pie.
Samsung's updated many of its applications with support for Android 9.0 Pie. The company says you'll need to update some apps including Calculator, Samsung Internet, Samsung Health, Samsung Notes, Samsung Members, and Samsung Pay individually.
These updates deliver new features and they'll help the apps maintain their performance as you transition from Oreo to Pie.
Apps that haven't been optimized for Android Pie might not work properly after you make the move.