1. A method for managing data set objects for use in connection with a dataflow graph processing data in a data processing system, the method including: storing a group of one or more data set objects in a data storage system, each data set object in the group representing a respective data set, the group including a first data set object representing a first data set, the first data set object having a plurality of modes, each of the plurality of modes corresponding to respective transformational logic, the plurality of modes including at least: a first mode for reading data records from the first data set, the first mode being associated with first transformational logic to be applied to data records read from the first data set, and a second mode for writing data records to the first data set, the second mode being associated with second transformational logic to be applied to data records before they are written to the first data set, wherein the first transformational logic is different from the second transformational logic; accessing information specifying the dataflow graph, the dataflow graph comprising a plurality of nodes and a plurality of links connecting the plurality of nodes, the plurality of links representing flows of data among nodes in the plurality of nodes; identifying the first data set object from the group of one or more data set objects; identifying a mode from the plurality of modes for the first data set object; adding, based on the accessed information specifying the dataflow graph, a first node to the plurality of nodes of the dataflow graph; and generating an association between the first data set object and the first node of the dataflow graph such that data processed by the first node is processed in accordance with transformational logic associated with the identified mode.