[Interest] Proper way of updating a model?

[Stephen Chu]

Thanks to everyone who helped on the 64-bit internal ID question I 
posted. I end up maintaining a copy of index-and-id mapping to work 
around it.

Now I have a question on how to properly update the model. My model is a 
read-only representation of a database. I am using a QTreeView to hold 
the model. The data themselves are not tree-like but I like the visual 
of QTreeView better.

The model needs to update itself periodically from the remote database. 
I keep a QList of data IDs and rebuild the list every time I get a new 
snapshot from the database.

What's the recommended way to reflect the changes to the view? I need to 
keep the current selection and scroll position of the QTreeView between 
updates.

Do I reset the model? Or do I remove deleted rows and insert new ones?

Thanks.