A data processing application for selectively processing data sub-segments using a data mask. Data segments are retrieved from a data source and pre-processed to include selected data sub-segments based upon the data mask. The masked data segments are communicated to a processor for processing. The excluded data sub-segments, if any, may be recombined with the processed data in post-processing, also using the data mask. Systems, methods, and articles of manufacture embodying the invention are described.