Abstract: A data processing system (1) has a data processing section (2) having user interface objects (10), work flow activity objects (11) and primitive objects (12). WFA objects (11) access a database (5) via a state machine (13). A data record is requested by a primitive object (12) being requested. The state machine (13) responds by retrieving a row of data from a table (6) and using this to instantiate a primitive object according to the data and the instruction from the requesting WFA object (11). A primitive object reference is stored in a temporary memory stack (15) and the reference is also copied to the requesting WFA objects (11). The primitive object (12) is then used subsequently for transaction processing until a transaction is complete. At this stage, the state machine (13) flushes the primitive objects to the database (5).