| 摘要 |
PURPOSE:To improve the performance of a data base managing system by lowering the frequency of updating of a bit map at the time of adding and deleting to and from a data base. CONSTITUTION:For instance, when requesting the deletion of a data, a data deletion control means 6 deletes the data whose deletion is requested, and thereafter, starts a bit map updating necessity deciding means 9. When the means 9 is started, the idle space quantity of the data page concerned before deleting and after deleting the data is converted to the bit map by a bit map converting means 12, and whether the values of the bit map before deletion and after deletion are equal or not is decided. In case when the values of the bit map are different, a bit map page containing a bit map corresponding to the data gage concerned is inputted from a data base 15 by a page input/output control means 13, the bit map concerned is updated by a bit map updating means 10, the bit map page concerned is outputted to the base 15 by the means 13, and thereafter, the control is returned to the means 6. |
