Redmine

Good catch! I'd vote +1 for your second solution, though it shouldn't introduce (more?) performance issues within such an implementation.

Still hard to use on a large project base : 100+ projects => "Completed in 24617ms", VS 1.6s for the test database. I had nearly the same results with my patch but it was less clean (I imagine parsing .descendants for each project costs a lot). I'll try to see if I can improve it.

OK, nothing to do with searching for .descendants in each project. I turned on development mode, I end up with some 922 queries to the database, maybe a bit too much ;) To be continued

And I've already made a few optimizations on the initial implementation. It's still very slow and I think we'll have to make some compromises, like removing project/version completion calculation which generates a bunch of queries. Project completion is not calculated properly BTW.