-on conflict (user_uuid, target_uuid) do update set perm_level=EXCLUDED.perm_level, traverse_owned=EXCLUDED.traverse_owned;
+on conflict (user_uuid, target_uuid) do update
+set perm_level=EXCLUDED.perm_level, traverse_owned=EXCLUDED.traverse_owned
+where #{PERMISSION_VIEW}.user_uuid=EXCLUDED.user_uuid and
+ #{PERMISSION_VIEW}.target_uuid=EXCLUDED.target_uuid and
+ (#{PERMISSION_VIEW}.perm_level != EXCLUDED.perm_level or
+ #{PERMISSION_VIEW}.traverse_owned != EXCLUDED.traverse_owned);