| 摘要 |
PURPOSE:To process the change of a random file storing plural kinds of data having address links with each other without using another working random file, by providing a memory area for positions of files set before and after the change of each data so as to avoid the breakdown of data obtained before change. CONSTITUTION:If a change request is given to the data A stored in a positive file F1, the storing addresses of data B and C are set on an old address table A2. The contents of the data A are changed and this data A is written to an unused part of the file F1. Then a new file address is set at the part of the address of the data A on a new address table A3. Both data B and C are processed in the same way, and old data A, B and C are deleted out of the file 1 with reference to the table A2. Thus it is possible to change data with use of the file 1 only and without using a secondary file and with use of both tables A2 and A3.
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