Rate       _split       _index _split_LIMIT       _regex
_split        657900/s           --         -26%         -31%         -38%
_index        890097/s          35%           --          -7%         -17%
_split_LIMIT  952857/s          45%           7%           --         -11%
_regex       1066336/s          62%          20%          12%           --