I encountered a performance issue with large data tables using a TableView in Qml and a C++ Model providing the data. If the TableView is completely scrolled down to the bottom and the model is updated via the beginResetModel() and endResetModel() methods, it takes multiple seconds for the TableView to restore the view. If the scroll position is at the top, the view updates immediately.
I added a print in a delegate item and it seems that every item delegate is created once, from top to bottom, instead of just updating the items that are in the current view.
The TableView docs mentions to set contentWidth and contentHeight to avoid unnecessary calculations and updates, but it seems not to help in my case.
I managed to reproduce it completely in a Qml example. I just defined one colum and 100,000 rows, scrolled down the view and a button triggers the model switch. It takes 3-4 seconds on my machine.
Is this a known TableView limitation? If so, do you know a workaround for this?