Abstract: A data processing device (DPD) comprises a main memory (MM) and a processing means (PM). Data from a data base system (DBS) is stored as pages in the main memory (MM). During processing of the individual objects (OB) of the pages (P) the access frequency to each object (OB) stored in the main memory (MM) is determined. Objects having similar access frequencies are collected in the same data storage section of the main memory (MM). In particular, data objects (OB) can be moved to higher order data storage sections to which a higher access frequency range has been assigned. Thus, data which is more frequently used by the processing means (PM) stays in the main memory (MM) longer and data objects which are not so frequently used are transferred back to the data base or are overwritten earlier.