Dynamic Select
Data Abstract for Cocoa comes with two samples that demonstrate using Dynamic Select to only retrieve certain fields from a table row when requesting a table.
Sample 1: Console based application
The Console Sample is typically located in /Developer/RemObjects Software/Samples/Data Abstract/Console/DynamicSelect, though you may have installed the sample in another location.
Sample 2: Desktop based application
The Desktop Sample is typically located in /Developer/RemObjects Software/Samples/Data Abstract/Desktop/DynamicSelect, though you may have installed the sample in another location.