Abstract: A community server categorizes and accumulates messages exchanged by users on a virtual community for respective topics. The community server includes a subscription type setting unit, which provides, to each user and predetermined administrator, a mechanism for selecting a subscription type indicating the way each user subscribes to messages posted to the virtual community. For this purpose, the subscription type setting unit manages the subscription types of respective users for each community using a subscription type table of community management information, and changes the subscription type in the subscription table in accordance with a request from each user and administrator.

Abstract: A synonym search section searches a synonym dictionary for synonym group identifiers indicating synonym groups to which tags included in first structure-designating information from a terminal belong. Based on a search result, a structure-designating-information generation section generates 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. A synonym-structure-template search section searches a synonym-structure-template management block for a synonym structure template that matches the second structure-designating information. An acquisition section acquires, from a database, a document structure in a structured document indicated by a structure template corresponding to the detected synonym structure template.

Abstract: On the basis of an index generation request which is sent from the outside to direct generation of character string concatenation index and which designates a tag assigned the generated character string concatenation index, a tag detection unit detects the tag designated by the index generation request, in a structured document which is newly stored or has already been stored in a document storing area. An index management unit generates the character string concatenation index assigned to the detected tag and stores the generated character string concatenation index in an index storing area. The generated character string concatenation index includes values of a plurality of text nodes concatenated. The text nodes are included in the structured document having the detected tag and depend on the detected tag.

Abstract: The storage area of a storage unit includes a file area and temporary write area. A pair of map tables are allocated in the storage area. An update processing unit executes update of a page in a file stored in a file area by writing updated data to an unused page acquired from a temporary write area. A commit module alternately writes a list of effective pages in the temporary write area to the pair of map tables whenever each of transactions is committed. A checkpoint processing unit writes back the updated data of each effective page in the temporary write area to the corresponding original page position in the file area.

Abstract: A community server categorizes and accumulates messages exchanged by users on a virtual community for respective topics. Since the community server includes a thread moving unit, i.e., a mechanism that allows an administrator to move a thread as a set of messages posted to a given virtual community to another virtual community, each user can utilize collected and accumulated knowledge via his or her desired interface. Since the administrator can move a thread between communities, virtual communities can be combined or divided.

Abstract: A structured document retrieval system includes a structured document database which manages a structured document by a tree structure including a plurality of hierarchical nodes, a unit which receives a traverse request from a client, the traverse request including base point node designation information to designate one of nodes in the structured document database as a base point node corresponding to a base point for retrieval and relative location information to designate a location of a traverse destination node relative to the base point node, and a traverse processing unit which performs a traverse process to move from the one of nodes designated by the base point node designation information to another one of the nodes in accordance with the relative location information, and acquires data corresponding to the traverse destination node from the structured document database.

Abstract: The storage area of a storage unit includes a file area and temporary write area. A pair of map tables are allocated in the storage area. An update processing unit executes update of a page in a file stored in a file area by writing updated data to an unused page acquired from a temporary write area. A commit module alternately writes a list of effective pages in the temporary write area to the pair of map tables whenever each of transactions is committed. A checkpoint processing unit writes back the updated data of each effective page in the temporary write area to the corresponding original page position in the file area.

Abstract: A synonym search section searches a synonym dictionary for synonym group identifiers indicating synonym groups to which tags included in first structure-designating information from a terminal belong. Based on a search result, a structure-designating-information generation section generates 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. A synonym-structure-template search section searches a synonym-structure-template management block for a synonym structure template that matches the second structure-designating information. An acquisition section acquires, from a database, a document structure in a structured document indicated by a structure template corresponding to the detected synonym structure template.

Abstract: A community server categorizes and accumulates messages exchanged by users on a virtual community for respective topics. The community server includes a user access limiting control unit. The user access limiting control unit determines user's access authority of each client terminal for each community as an access destination. For this purpose, the user access limiting control unit manages a community type indicating the open level of each community, and a member type indicating the participation attribute of each user to the virtual community, using community management information, and limits access to a community as an access destination for each client terminal on the basis of the combination of the community type and member type.

Abstract: A community server categorizes and accumulates messages exchanged by users on a virtual community for respective topics. Since the community server includes a thread moving unit, i.e., a mechanism that allows an administrator to move a thread as a set of messages posted to a given virtual community to another virtual community, each user can utilize collected and accumulated knowledge via his or her desired interface. Since the administrator can move a thread between communities, virtual communities can be combined or divided.

Abstract: A community server categorizes and accumulates messages exchanged by users on a virtual community for respective topics. The community server includes a subscription type setting unit, which provides, to each user and predetermined administrator, a mechanism for selecting a subscription type indicating the way each user subscribes to messages posted to the virtual community. For this purpose, the subscription type setting unit manages the subscription types of respective users for each community using a subscription type table of community management information, and changes the subscription type in the subscription table in accordance with a request from each user and administrator.