Hello,

I ran into some problems when displaying more than 72 million rows in a table (the view only showed garbage). The reason here was that internally the view components do all computations with integer (signed 32 bit) and the default row height is 30, so the view produces integer overflows when working with that amount of data. There is already a bug note on this in the Qt bug tracker.

For working around this I have chosen the following approach (maybe this could help you too):
1. I divided my model into "pages" consisting of up to 60 million rows. The view will display only the currently loaded "page" and the scrollbar is used for scrolling inside this "page".
2. I added a - and + button at the top and bottom of the view vertical scrollbar. Clicking the + button will move the model page by half page size down and pressing - button will move it by half page size up. The view will get updated when clicking those buttons.

In your situation you can unload old / load new data into the model when the +/- buttons are clicked.

Regards
ars