Abstract: A data processing device according to the present invention includes: a partition unit that horizontally partitions records included in table data into a plurality of blocks, the horizontal partitioning indicating partitioning that uses records as a unit; a statistical value calculation unit that calculates, for each of the blocks, a statistical value of an attribute included in the records of the block; a determination unit that determines, when processing a query for performing aggregation processing after record selection processing with respect to the table data, based on the statistical value, for each of the blocks, whether all records in the block are selected or not based on the selection processing; and a query execution unit that uses, for a block determined that all records are selected based on the determination unit, the statistical value of the determined block as a result of the query for the determined block.