| 摘要 |
PURPOSE:To improve retrieving efficiency by dividing a data file into a data file part and a control file part. CONSTITUTION:A data file is divided into a data file part which actually stores data and a control file part which stores the control data on the data register state, etc. for each identification number and the data storing addresses of the data file part. The storing area of the control file part is divided into two layers and stores data in the 1st area 121 by giving an access to a storing cell with a hash key calculated from an identification number. When a collision occurs with the same hash key, the idle state of the 2nd area 122 is checked by a bit map for control of use of the area 122 for storage of data. The file part of the data file part has polymerization of a cell of the 2KB capacity, for example and performs the control for use of cell by the bit map. If the storage of data is impossible within a cell, the bit map is retrieved for detection of an idle cell. Then the next writing address is written to said idle cell and links are formed successively to the following cells for writing addresses. |
