RAMArray is compatible to ZBigArray in API and semantic, but stores its data in RAM only. It is useful in situations where ZBigArray compatible data type is needed, but the amount of data is small and the data itself is needed only temporarily - e.g. in a simulation.
Please see details in individual patches.
Original merge request by @klaus (https://lab.nexedi.com/nexedi/wendelin.core/merge_requests/8). /cc @Tyagov