when a RETRIEVE Command is send to an NG/AMS Server it is possible to specify that the NG/AMS Server should execute a Data Processing Plug-In (DPPI) on the file. If this is the case, only the result/output of the DPPI will be send back to the requestor rather than the complete file.
	The actual processing of the file is carried out on the node where the file is stored. I.e., if a Main Node is handling the request and acting as proxy, it will forward the Retrieve Request to the node hosting the file. The processing will take place on that node.
	Client applications may issue parallel Retrieve Requests and in this way use the NGAS Cluster as a parallel number cruncher. In addition, less network traffic is needed.