Apparatus and method for searching structured documents

A method of searching a plurality of structured documents stored in a database for a document structure in a structured document corresponding to first structure-designating information, in response to a search request containing the first structure-designating information and issued from a client terminal, the first structure-designating information indicating an arbitrary document structure including tags, comprising:

• searching synonym group identifiers, stored in a synonym dictionary and indicating synonym groups, for synonym group identifiers indicating synonym groups to which the tags included in the first structure-designating information belong, the synonym dictionary storing the synonym group identifiers uniquely assigned to the synonym groups which contain synonyms of tags, and storing the tags belonging to the synonym groups;
• generating, based on a search result of the searching, second structure-designating information in which the tags included in the first structure-designating information are replaced with the respective synonym group identifiers indicating the synonym groups to which the tags of the first structure-designating information belong;
• searching synonym-structure-template-storing means for a synonym structure template corresponding to the second structure-designating information, the synonym-structure-template-storing means storing synonym structure templates in which all tags included in structure templates as templates of tag structures are replaced with synonym group identifiers indicating synonym groups to which said all tags included in the structure templates belong, the structure templates being stored in structure-template-storing means in relation to identifiers assigned to the structure templates, the structure templates corresponding to document structures included in the structured documents stored in the database;
• and
• acquiring, from the database, a document structure in a structured document indicated by a structure template corresponding to the searched synonym structure template.

A storage medium storing data for a structured-document search in which a database storing a plurality of structured documents is searched in response to a search request from a client terminal to detect a document structure included in a structured document corresponding to the search request, the storage medium comprising:

• a plurality of structure templates as templates of tag structures, the structure templates being associated with identifiers assigned to the structure templates, and corresponding to document structures included in the structured documents stored in the database;
• a synonym dictionary which stores synonym group identifiers indicating synonym groups, and tags belonging to the synonym groups, each of the synonym groups being a set of tags having a common concept;
• and
• synonym structure templates corresponding to the respective structure templates, the synonym structure templates being generated by replacing all tags with synonym group identifiers indicating the synonym groups to which said all tags belong, said all tags being included in the structure templates corresponding to the synonym structure templates.