DATA PROCESSING APPARATUS, DATA PROCESSING METHOD, AND COMPUTER PROGRAM PRODUCT, AND ENTRY PROCESSING APPARATUS

According to an embodiment, an update request reception unit receives a data update request to update data stored in a storage. A read request unit makes a read request to read data from the storage. A data reception unit receives the data from the storage. An update value calculator calculates an update value of the received data. A write request unit makes a write request to write the calculated update value into the storage. A data processing execution unit executes reading and writing on the storage. A history processing unit generates a history of the reading and deletes a history of reading corresponding to the writing. An update information estimator estimates, from the generated history, update information indicating how the data is to be updated. A data update unit updates the data read according to the estimated update information and output new updated data to the data reception unit.