Function left_out_note 

pub fn left_out_note(
    column: &ColumnDrift,
    dataset: &DatasetSchema,
    rows: usize,
    filtered: bool,
    sorted: bool,
) -> Note

Rows a filter or sort leaves out, because the column it names is not read from the files those rows came from.

The only note here about the view rather than the dataset, and the only one datui writes in answer to something the user just did.

It is phrased about the files, not about the view, and that is the whole care of it. “2 rows are left out” reads as a claim that the view is two rows shorter, which is not true when a filter had already dropped one of them; how many rows are in the files that hold the column in another type is a fact of the footers, true whatever else the view is doing. Both counts here are of that kind.

The cost of saying it that way is that the note also appears where those rows had already gone — a filter that excluded them, then a sort on the column. It is still true there, and the alternative is a count of what the view actually lost, which cannot be had without collecting the frame twice.