This ensures that if another process did a split on the relevant leaf, then subsequent reads will see a conflict in the master group; and then do a read repair on that.
riak_column is a concurrent dict abstraction on top of riak. It's a variant of vector map, which gracefully handles many updates because the contents is split into groups controlled by bit-prefix of the sha of the key. Intended use is for secondary indices and/or materialized views on top of riak.
The created objects hold an erlang binary with a vset structure, so that conflicting updates of links can be managed properly when merging such link objects.