| 摘要 |
PROBLEM TO BE SOLVED: To improve retrieval speed while maintaining features of a conventional basic 5-line table. SOLUTION: This data structure for a database includes a second type of records containing, for each record of a first type containing values for one or more items defined in an original RDB, item names of the defined items, values thereof, and identification data of the record concerned by the number of the items. In the second type of records, a filter item for extracting a group of the second type of records related to one record of the first type together at the time of retrieval is defined in conformation to each item retrievable in the first type of records. In the filter item, the values of the corresponding items are set for all of a group of the second type of records. Since all records of one group corresponding to one original record can be extracted by one retrieval by retrieving the filter items, the retrieval can be speeded up. COPYRIGHT: (C)2008,JPO&INPIT
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