| 摘要 |
PURPOSE:To prevent the increase of the capacity of an index area due to the increase of records and the deterioration of the access speed and also to facilitate the control of an index by producing an index for records that received accesses at access of records. CONSTITUTION:When a record processing request is received, a record processing means 3 retrieves an index memory means 2 and extracts a prescribed area of a data memory means 1 storing a record containing a key designated by the key of the relevant record. Then an index production means 4 checks whether or not a fixed distance is secured between the stored position of the record containing a key that received an access from the means 3 and the store position within the index information stored in the means 2 in case the index information on said record containing a key is not stored in the means 2 yet. When said fixed distance is secured, the index information is produced to the record received an access and written into the means 2. Thus the access operations are ensured with high efficiency without increasing the capacity of an index area despite the increase of data records. |
