| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To maintain a state capable of starting retrieval of index information within allowable retrieval time even when the addition of index information is repeated. <P>SOLUTION: An index construction method is executed in a document retrieval apparatus, wherein an index is composed of index information adopting a character string as an index item and a trie adopting a character included in each index item as a node. The index information is managed in each index information block which is composed of a plurality of index information having the same index item. One or more index information blocks are associated with each node of the trie to correlate the index information. The document retrieval apparatus, if the retrieval time of index information related to the node of the trie exceeds a prescribed threshold when a plurality of index information blocks correspond to each node of the trie, divides the index information correlated to the node of the trie so that the index information blocks included in the corresponding plurality of index information blocks may not be divided on the way, generates a new node connected to the lower stage of a master node of the corresponding trie node and correlates the divided index information to the new node. <P>COPYRIGHT: (C)2009,JPO&INPIT</p> |
