Apparatus, method, and computer program product for managing structured documents

A structured document managing method comprising:

• analyzing a difference between document identifiers of a pair of vocabulary indexes adjacent to each other in a page and a difference between element identifiers of a pair of the vocabulary indexes adjacent to each other in the page, the vocabulary index being stored in the page stored in an index storing unit that stores, in the page as a fixed-length storage area, the vocabulary index which associates vocabulary identifiers for identifying vocabularies included in a structured document having a layered logical structure and specific information including the document identifiers for identifying the structured document where the vocabularies appear and the element identifiers for identifying elements where the vocabularies appear, the elements being actual information corresponding to the logical structure in the structured document;
• judging whether the difference between the document identifiers exceeds a first threshold value;
• dividing the page into a plurality of blocks between the vocabulary indexes where the difference between the document identifiers exceeds the first threshold value, each of the plurality of blocks including one of a plurality of the vocabulary indexes;
• judging whether the difference between the element identifiers exceeds a second threshold value decided in advance when the document identifiers coincide with each other;
• dividing the page into the blocks between the vocabulary indexes where the difference between element identifiers exceeds the second threshold value;
• and
• calculating a first range representing a range of the specific information of the vocabulary indexes included in the blocks, and storing the first range in each of the divided blocks in the index storing unit.

A non-transitory computer readable medium including programmed instructions for managing a structured document, wherein the instructions, when executed by a computer, cause the computer to perform:

• analyzing a difference between document identifiers of a pair of vocabulary indexes adjacent to each other in a page and a difference between element identifiers of a pair of the vocabulary indexes adjacent to each other in the page, the vocabulary index being stored in the page stored in an index storing unit that stores, in the page as a fixed-length storage area, the vocabulary index which associates vocabulary identifiers for identifying vocabularies included in a structured document having a layered logical structure and specific information including the document identifiers for identifying the structured document where the vocabularies appear and the element identifiers for identifying elements where the vocabularies appear, the elements being actual information corresponding to the logical structure in the structured document;
• judging whether the difference between the document identifiers exceeds a first threshold value;
• dividing the page into a plurality of blocks between the vocabulary indexes where the difference between the document identifiers exceeds the first threshold value, each of the plurality of blocks including one of a plurality of the vocabulary indexes;
• judging whether the difference between the element identifiers exceeds a second threshold value decided in advance when the document identifiers coincide with each other;
• dividing the page into the blocks between the vocabulary indexes where the difference between element identifiers exceeds the second threshold value, and
• calculating a first range representing a range of the specific information of the vocabulary indexes included in the blocks, and storing the first range in each of the divided blocks in the index storing unit.