Optimize case of "no projection" (include all) so that doc_json embedded directly

[tatu-at-datastax]

One possible optimization we may be able to do is to short-circuit "parse-JSON from doc_json, modify, write as JSON" for the special case of no/empty Projection: this is where we may be able to simply inject contents of doc_json into output and avoid at least serialization, but possibly also deserialization cost.

[tatu-at-datastax]

After studying the code I am not sure this is feasible to do: document is carried along as JsonNode-based representation which is mutable, and the original String containing doc_json is not passed, nor is it clear how to keep track of changes to Document object (to know if it might have been changed).

Will keep open for a bit in case I get an idea of how to work around challenges.

[tatu-at-datastax]

I don't think this is feasible as things are; closing.