[lucian1900]

What I'd like is a scrollbar absolute to the entire dataset, and some hint on how much of it is loaded.

[generateui]

That's where inifinite scroll is a good idea. Infinite scroll is usually correctly applied to datasets where it is unknown how many items the dataset consists of. E.g. google images, tweets, et cetera.

We already have what you want, it's called a scrollbar ;).

[lucian1900]

Where the dataset size is known, but just very large, a scroll bar and lazy loading of items is what I want.

For datasets with unknown size, just make sure scrolling is only ever needed for looking at previous pages.