Dx is an semi-structured in-memory datastore with copy-on-write semantics for
fast concurrent access. Records are schema-less name-value pairs that are
grouped together into buckets. Each record must have an integer id field
that is unique within the bucket.
Mutations to a store are handled by a writer instance which buffers a set of changes and then produces a new store copy. The backing data is held in persistent data structures for efficient reuse of unmodified data and to make mutations thread safe.