Hi @vitlibar,
In http implementation, ClickHouse will return format of query result in header `X-ClickHouse-Format`. Can we return format in gRPC response as well? This helps client like JDBC driver for deserialization(without the need for parsing the query).
{
            
            
            
            std::lock_guard lock{mutex};
            size_t callback_id = next_callback_id++;
            auto & callback_in_map = callbacks[callback_id];
            callback_in_map = [this, callback, callback_id](bool ok)
            {
                CompletionCallback callback_to_call;
                {
                    std::lock_guard lock2{mutex};
                    callback_to_call = callback;
                    callbacks.erase(callback_id);
                }
                callback_to_call(ok);
            };
            return &callback_in_map;
        }
        grpc::ServerContext grpc_context;
    private:
        grpc::ServerAsyncReaderWriter<GRPCResult, GRPCQueryInfo> reader_writer{&grpc_context};
        std::unordered_map<size_t, CompletionCallback> callbacks;
        size_t next_callback_id = 0;
        std::mutex mutex;
    };
    enum CallType