Data management apparatus and method for efficiently generating a blocked transposed file and converting that file using a stored compression method

摘要

A data management apparatus and method provide for a virtual conversion by repeatedly reading at least one record from an input file having a plurality of records, each record including a plurality of fields, and adding the at least one record to a buffer. The records in the buffer are then converted into a post-conversion block on a field-by-field basis until data size of post-conversion blocks for each kind of field of the records in the buffer exceeds a threshold size. The number of records in the post-conversion blocks can be determined by counting the records in the buffer during a process immediately preceding a time when the data size exceeds the threshold size, and storing that number. The conversion is completed by reading out records of the stored number of records from the input file, converting the records read out into post-conversion blocks on a field-by-field basis, and storing the post-conversion blocks.