- $db->problems->search({-or => ['contest_problems.contest' => undef, 'contest.stop' => {'<=', time}], 'me.private' => 0}, {join => {'contest_problems' => 'contest'}});
+ $db->problems->search({-or => ['contest_problems.contest' => undef, 'contest.stop' => {'<=', time}], 'me.private' => 0}, {join => {'contest_problems' => 'contest'}, distinct => 1});