Release 10.1A: OpenEdge Development:
ProDataSets

Summary

This chapter has illustrated several techniques you can use to access data more flexibly using ProDataSets, including:

Setting a batch size and retrieving large amounts of data a batch at a time, to avoid the overhead of loading all rows into a temp-table and sending all the data across a network at one time.
Using the OUTPUT APPEND parameter mode for the ProDataSet to build up both header and detail information on the client a step at a time.
Using the include-field list to limit the number of fields that are actually populated with data from the Data-Source, and therefore reducing the amount of data sent across the network to the client.
Using OFF-END and FIND-FAILED event handlers to retrieve data transparently to add to the client’s ProDataSet when it is needed.

You could extend this example in many ways. For example, to support a FIND LAST or other client-side event to jump to a later batch of rows, and to enable scrolling and retrieving batches of rows backwards as well as forwards, and so on. Much of this simulates what the SmartDataBrowser object does in conjunction with a SmartDataObject for data retrieval in an ADM2 application.