  CRDT[24] Sets as implemented in Riak[6] perform poorly for writes, both as
cardinality grows, and for sets larger than 500KB[25]. Riak users wish to
create high cardinality CRDT sets, and expect better than O(n) performance for
individual insert and remove operations. By decomposing a CRDT set on disk, and
employing delta-replication[2], we can achieve far better performance than just
delta replication alone: relative to the size of causal metadata, not the
cardinality of the set, and we can support sets that are 100s times the size of
Riak sets, while still providing the same level of consistency. There is a
trade-off in read performance but we expect it is mitigated by enabling queries
on sets.
