A method and system are described for preparing a batch 15 of data sets 1-11 for a batch processing using a predetermined correlation encoding operation. In a first step, the batch 15 of data sets 1-15 is analysed to determine a plurality of correlation parameters 22 representing degrees of correlation between member data sets 1-11 of said batch 15 of data sets 1-11. In a second step, the correlation parameters 22 are used to generate an optimized correlation dependency graph 16 of the member sets 1-11 for performing the predetermined correlation encoding operation. By optimizing the correlation dependencies between data sets for subsequent processing, e.g. data compression, of the data sets, the advantages of correlation encoding can be used, even for data sets which appear a priori to be unordered and only weakly correlated.