摘要 |
According to the present invention, a header includes delete history data (counter) area where a delete history of the logically subsequent record header is written in. By sequentially referring to record headers by using this data, a logical storing order of records is not destroyed even if a delete instruction is executed. In addition, the header has physical position data. Accordingly, when a squeeze instruction is executed after the delete instruction, the logical storing order of records is not destroyed and an empty area in the block can be effectively utilized.
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