you can try with an extended attribute filter then. use your sql debug output to see how normal reverse_related_objects works and do something similar with your extended attribute filter.
for extended_attribute_filter you can have a look at ezstarrating extension.
about template function, i wouldn't go like that. i mean, it seems you're doing the database query and then ordering the results, but with an extended_attribute_filter you can just the results sortered. better for perfomance i think.
Thanks Carlos, I'll check out the extended attribute filter and see if I can make it do sorting on this specific attribute I have. I also appreciate the feedback on the template function idea, it does make more sense to do the sort on the fetch.
Sure. suppose you have a 10.000 objects, but you only need to show 10 of them ordered by one of the attrs. usign that template custom operator, you will have to get all of 10.000 and then php will sort them. then you will have to use some kinda array_slice operator to get only 10.
you can certainly do all those steps in just one query.