| 摘要 |
PURPOSE:To extract data in sorting order at a high speed by generating a relative address table of all page numbers of data to be sorted in a main storage device or external storage device, and sorting and rearranging the data according to the table. CONSTITUTION:Data is represented by page numbers of a disk file and in-page relative addresses and the sorting order is expressed by their arrangement order, so sorting results are stored with small storage capacity. Then, the stored sorting results become more than those in tree structure of each page and the number of times of input to and output from the buffer 8 and external storage device 4 for knowing the sorting order decreases. When one data is outputted, a reference to the sorting table 7 and a reference to data based upon the sorting table are both necessary, but reference records in the sorting table 7 are already present on the buffer frequently, so the input/output operation of the external storage device 7 is performed only once. Thus, data are processed at a high speed.
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