1. A computer-implemented method for qualified checkpointing of a data flow model having a plurality of data flow operators and a plurality of links connecting the data flow operators, the method comprising: selecting a link of the plurality of links of the data flow model, based on a set of checkpoint criteria; generating a checkpoint for the selected link and by operation of one or more computer processors, wherein the checkpoint is selected from a plurality of different checkpoint types, wherein the generated checkpoint is assigned to the selected link; and executing the data flow model, wherein at least one link of the plurality of links of the data flow model has no assigned checkpoint.