Do note that 9/10 people in the know will tell you that global variables are a bad idea. The idea of OOP is to encapsulate and keep things on the need-to-know only basis. Not the other way round.
It’s just bad practice imho. Once you structure your code properly and learn blueprint comms (direct, dispatchers and interfaces), you’ll never want or need global variables.
And if you ever need to fetch something, it’s always a cast-away in a framework class that is already loaded, making things somewhat global anyway.
But an interface to a framework class that holds a refence to a data base actor is not a bad idea.