Hmm.. There was an earlier proposal to add a SplittableStore for a similar use-case:
https://github.com/twitter/storehaus/pull/191#issuecomment-32304833

Perhaps it's now time to add it. How about?
```scala

trait SplittableStore[R, K, V](store: ReadableStore[K, V])
  extends ReadableStore[R, Spool[K, V]) 
```
And then creating a `CassandreSliceStore` that implements this?