queen vs rook?

I was always wondering how to win an endgame queen vs. rook. Luckily it never appeared in any of my games yet.
What I know is, that there is a position from which you can reach a forced win (see below). What I also know is there are endgame databases for all positions with 5 pieces (maybe already 6 by now?) so it should be possible to force a win from any position. Or are some draw?



This is a position from where Black to move (first move will be Re7) White can force win. Euwe did the analysis on this. First the Black king will be forced to the g-file with all pieces remaining in the same constellation and then White can win the rook (Qe8-e4!).

Here are some Q vs. R draws:

White - Kg8, Rg7; Black - Kh1, Qf6.
White - Kh1, Re1; Black - Kf4, Qf2.
White - Kh7, Rg6; Black - Kh2, Qf1.

it barely happens, usually resination occur before that.