| 摘要 |
PURPOSE:To ensure promptness and high reliability of response to request for retrieval and facilitate management of file by arranging files redundantly and adopting dispersed constitution that enables sort by multiple keys. CONSTITUTION:When request for retrieval is inputted by an input/output device 21, the kind of key is discriminated, and corresponding inverted index is read out on a main memory 26. Then, address of record group of corresponding record file is obtained by searching the inverted index file in the device 26 and obtaining a pointer value basing on a value designated by condition of retrieval. Basing on this address, corresponding record group in a secondary memory 28 is read on the device 26 and displayed on the device 21 as the result of retrieval through a main memory control unit 25, etc. Thus, by arranging files redundantly in the device 28 and inputting by a multiple key device 21, efficiency of information retrieval is increased and management of files is made easy. |
