Sorry about the flip flopping, but you are right: there are reports of people using 2i for crazy large sizes and this would hurt. I've tested the original prepend + foldl and that works as well and is more efficient. You can try the secondary_index_tests and verify_2i_limit tests of this branch for your own testing if you need: https://github.com/basho/riak_test/tree/eas-use-riakhttpc-in-2i