| 摘要 |
A data management system and method enable the storage of along record held in volatile memory as a set of keyed physical records of restricted length in non-volatile storage while minimising movement of data. The logical record 12 to be stored is logically divided into a number of physical record portions 14,15,16 to each of which is prepended a key with a unique sequence number. By starting from one end of the record with the key of highest sequence number and copying the physical record consisting of key plus data into the data set, successive physical records can be assembled in situ by overwriting the previous record's data portion with the current record's key. This ensures that the split logical record data need only be moved once as it is transferred to non-volatile storage as physical records 24,25,26 of the data set. The original logical record can be reassembled (Fig 4) by reversing the above procedure. Thus, the last written (lowest sequence number) physical record is written into main memory first and subsequent physical records are written into main memory so that their data portions overwrite the previously written record's key.
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