The field shared file management device, the data division which is formed from rehabilitation manner of the deletion member of the field

摘要

PPROBLEM TO BE SOLVED: To release data areas first when deleting members, and restore some deleted members without lowering deletion processing performance. PSOLUTION: A device comprises a deletion means for setting invalid validity information in an entry for a member to be deleted, moving the entry to the end of a directory block, inputting all the data blocks for the member to be restored according to a leading data block address in the entry and next data block addresses in the data blocks, and setting corresponding BAM description bits unused, and a restoration means for inputting the data block according to the leading data block address in the entry for the member to be restored, and if the corresponding BAM description bit is set unused, inputting all the data blocks for the member to be restored according to the next data block addresses as checking that the bits are set unused, setting the corresponding BAM description bits used, and setting valid validity information in the entry. PCOPYRIGHT: (C)2007,JPO&INPIT