| 摘要 |
PURPOSE: To improve performance by reducing the number of time of key comparison as much as possible without delection of an equivalent key record in the sorting of the record for which the equivalent key record exists. CONSTITUTION: A competition control table 10 setting the information for every record participating in the competition at the time of sorting is provided with the equivalent key flag for every record. When a competition means 2 detects an equivalent key record, the means 2 sets the equivalent key flag corresponding to the record which becomes a winner to ON. This equivalent key flag is added as control data to the record at the time of the output to a string to be an intermediate result. When a merge means 4 obtains the next record from the string to which the winner of the competition belongs at the time of the merge of the string, the next acquired record is immediately outputted to the string without participating the record in the competition if the equivalent key flag added to the record of the winner is ON. |
