DATA BASE REGION SECURING SYSTEM

摘要

PURPOSE: To easily secure a required region at the time of data restoration by setting a region holding mark when the length of data after updating gets shorter than before updating and holding this data until the time of work unit completion. ;CONSTITUTION: When data deletion is requested, a deletion processing part 221 sets a work unit ID (identifier) as the region holding mark at a specified position inside this data. And when the work unit which has performed the data deletion request is interrupted in the process, a recovery processing part 223 turns the work unit ID inside the data to '0.' Also, when retrieving request is performed to the data, at an retrieving processing part 222, the work unit ID inside the data is confirmed, and when it is '0,' this data is retrieved. And when it is not '0,' nor a self work unit ID, the retrieving processing part 222 waits the processing until the work unit of this work is completed. Also. when it is the self work unit ID, the retrieving processing part 222 treats this data as deleted data and retrieves the next data.;COPYRIGHT: (C)1993,JPO&Japio