| 摘要 |
PROBLEM TO BE SOLVED: To maintain the strictness of retrieval while maintaining satisfactory update retrieval performance by constructing an index of a category suitable to each element. SOLUTION: A retrieval expression processing part in a data retrieving part 16 analyzes a retrieval expression given from the outside, extracts a retrieval condition and acquires a set of candidates for retrieval results satisfying the retrieval condition. A value extracting part in an index managing part 15 acquires a history of retrieval conditions applied to a corresponding element of the elements included in a structured document stored in a structured document DB 21. An index category determining part in the index managing part 15 determines an index category on the basis of the largest retrieval category in the history of the retrieval conditions applied to the corresponding element of the elements included in the structured document to which an index should be attached. An index constructing part in the index managing part 15 constructs indexes of the index category determined by the index category determining part and stores them in an N-gram index DB 22, a word index DB 23 or a B-tree index DB 24. COPYRIGHT: (C)2008,JPO&INPIT
|
