Abstract: Bit string searching apparatus using a coupled node tree with a root node and a node pair stored in adjacent areas that is formed by a branch node and a leaf node, branch nodes, or leaf nodes; the branch node including a discrimination bit position in the search key and information indicating a position of a primary node that is one node of a node pair; the leaf node including an index key formed by a bit string; from the root node of an arbitrary subtree of the coupled node tree, linking is repeated based on the search key's bit value at the discrimination bit position and information indicating a position of a primary node until a leaf node is reached; an index key stored in the leaf node is obtained as a search result key of the subtree by means of the search key.

Abstract: Provided is a search method which is appropriate for handling a don't-care bit. A coupled node tree comprises a root node and a node pair, the node pair being a branch node and leaf node, or a pair of branch nodes, or a pair of leaf nodes located in adjacent storage areas. The branch node includes a discrimination bit position of a search key for the bit string search, which key is encoded so as to distinguish between don't-care bits and significant bits, and position information indicating a position of a primary node, which is one node of a node pair of a link target. A leaf node includes an index key which is a bit string in the status of either being or not being encoded.

Abstract: A method of database update processing for updating efficiently database index keys, when new database index keys are supplied to replace index keys already in the database, generates a delta data between the new and old data comprising insert and delete keys by delete processing from a coupled node tree holding the index keys in the old data using index keys of new data as delete keys, and generates new data by delete and insert processing from and into a coupled node tree holding index keys in old data as index keys using the delete keys and insert keys of the delta data.

Abstract: A bit string searching apparatus has a coupled node tree, having a root node and a node pair, the node pair being a branch node and leaf node, or a pair of branch nodes, or a pair of leaf nodes in adjacent storage areas, the branch node including a search key discrimination bit position and information indicating a position of one node of a node pair of a link target, and the leaf node including an index key that is a bit string that is the target of a search, wherein a search for an index key from the root node to a branch node using a search key is executed by repeatedly and successively linking to one node of a node pair of a link target, according to a bit value of a search key at the discrimination bit position in the branch node, until reaching the leaf node.

Abstract: The sort processing of keys to be sorted, which keys are expressed as bit strings involves a classification processing. In the classification processing, a bit string comparison between a reference key and a key which is an object of the classification is performed, and a difference bit position is obtained that is the bit position of the first bit that differs in the bit string comparison and the keys to be sorted are classified by the difference bit position into key groups with the same difference bit position.

Abstract: A code ID range table holding code ID ranges for each code and a next code ID table holding next code IDs, which are the code ID located next to each code ID, are created. Code ID ranges of codes configuring a search code string are read out from the code ID range table for the search target code string, and the stored next code ID corresponding to a code ID included in the code ID range of the head code in the search code string is read out from the next code ID table while the stored next code IDs corresponding to the next codes are successively read out from the next code ID table, and the next code ID read out from the next code ID table is verified whether it is included in the code ID range read out from the code ID range table.

Abstract: To perform a path finding for a network by traversing mutually connected links by means of a link destination table that is a data configuration for representing the network. The link destination table contains, for link IDs of each of the links in the network, a node ID of a node on one side of the link, destination link IDs for the node on one side which are link IDs of other links to that node, a node ID of the node on the other side of the link, destination link IDs of the node on the other side which are link IDs of other links to that node, and interval costs.

Abstract: A storage area management method for a data storage apparatus partitions an acquired storage area into storage areas with differing power-of-2 sizes and manages each of them. Also, a storage area allocation method receives an allocation request for a storage area that includes a requested allocation size, and acquires an available storage area whose size is the smallest power-of-2 size encompassing the requested allocation size, and obtains a binary expression of the requested allocation size, and in response to the received allocation request, allocates a contiguous storage area comprised of storage areas each of whose size is a power of 2 of a value of a bit position wherein a 1 is set in the binary expression.

Abstract: Using a tree configuration wherein node groups of four or more nodes composed of combinations of branch nodes, leaf nodes or empty nodes are linked into a tree form, a bit string search by a search key string is enabled by repeatedly linking to one of the nodes of a node group to which a primary node belongs in response to the bit values of keys of the search key string at the discrimination bit position included in the branch node.

Abstract: An index key is a key string formed of three or more keys whose tail-end key is unique, and a search key string for a bit string search has a unique key as its tail-end key. A branch node includes a search key sequence number expressing the position information of a key in the search key string to be used in the bit string comparison during the bit string search and the discrimination bit position for that key. Search for index keys is performed by extracting from the search key string the key with the search key sequence number in the branch node and repeatedly linking to one of the nodes of a node pair of the link target in response to the bit value at the discrimination bit position of that key until the leaf node corresponding to that index key is reached.

Abstract: A method of database update processing for updating efficiently database index keys, when new database index keys are supplied to replace index keys already in the database, generates a delta data between the new and old data comprising insert and delete keys by delete processing from a coupled node tree holding the index keys in the old data using index keys of new data as delete keys, and generates new data by delete and insert processing from and into a coupled node tree holding index keys in old data as index keys using the delete keys and insert keys of the delta data.

Abstract: To realize a high speed merge sort method by applying a coupled node tree, which method extracts a smallest or largest key from a plurality of sorted key storage areas in each of which is stored keys comprised of bit strings that are sorted, and generates a coupled node tree for merge while adding a processing source identifier that identifies the sorted storage area wherefrom the key has been extracted, and repeats the actions of writing out into the merged key storage area a key being obtained by a minimum or maximum value search on the coupled node tree and deleting the key, and inserting into the coupled node tree a key by extracting the key from one of the plurality of sorted key storage areas.

Abstract: To provide a method that lessens the reduction in efficiency of processing using a coupled node tree even if the scale of the coupled node tree grows large. Is stored a termination node, whose discrimination bit position has a value smaller than 0, in a search path stack that holds the search history while successively storing therein branch nodes that have been traversed in the search path. The coupled node indicator of the stored branch node is converted to a value wherein a 1 is added if the link target is node [1].

Abstract: Provided is a search method which is appropriate for handling a don't-care bit. A coupled node tree comprises a root node and a node pair, the node pair being a branch node and leaf node, or a pair of branch nodes, or a pair of leaf nodes located in adjacent storage areas. The branch node includes a discrimination bit position of a search key for the bit string search, which key is encoded so as to distinguish between don't-care bits and significant bits, and position information indicating a position of a primary node, which is one node of a node pair of a link target. A leaf node includes an index key which is a bit string in the status of either being or not being encoded.

Abstract: A coupled node tree comprises a root node and a node pair, the node pair being a branch node and leaf node, or a pair of branch nodes, or a pair of leaf nodes arranged in adjacent storage areas. The branch node includes a discrimination bit position of the search key and the first position information of a primary node, one node of a node pair of a link target. The leaf node includes the second position information of the storage area holding an index key that is the target of a search. According to a bit value of the search key of a discrimination bit position in the branch node, repeated linking to a primary node of a node pair of the link target or a node at a position in a memory area adjacent thereto until a leaf node is reached.

Abstract: A coupled node tree has a root node and a node pair, the node pair being a branch node, which includes position information of a link target node pair, and a leaf node, which includes a search target index key, or a pair of branch nodes, or a pair of leaf nodes located in adjacent storage areas. The nodes of the coupled node tree are backed up in a depth precedence search sequence. The coupled node tree is restored by repeating the following process: reading out the nodes in the sequence they are backed up, storing in a stack the position information of the node to be restored, successively restoring child nodes as long as branch nodes are encountered, restoring a leaf node which is read out and then, tracing back up the stack, a decision being made as to which node is next to be restored.

Abstract: A coupled node tree comprises a root node and a node pair, the node pair being a branch node and leaf node, or a pair of branch nodes, or a pair of leaf nodes located in adjacent storage areas. The branch node includes a discrimination bit position of the search key and a position information of a primary node, which is one node of a node pair of a link target. The leaf node includes an index key that is a bit string that is the target of a search. A coupled node tree is searched using a longest-match/shortest-match search key and the longest-match/shortest-match node is determined through a comparison of the difference bit position between the index key resulting from the search and the longest-match/shortest-match search key and the discrimination bit position of a branch node on the search path memorized when the search is performed.

Abstract: In map data having link information, each of the links has reference information regarding a start point node of the link, a next link in a series of links, and an upper link. Further, links are memorized in a form of link list, and the position of the link in the link list is not changed in the course of adding/deleting a link, thereby enabling a direct reference to each of the links in the link list by the position of the link. The link information organized in the above-described manner enables the ease of the update of the map data as well as the speed-up of the calculation of, for example, a navigation route.

Abstract: To provide a method that minimizes efficiency reductions in processing coupled node trees even if the size of the coupled node tree grows large. In basic searching or maximum or minimum value searching, the search history, not only the address information of the storage area wherein a node is stored but also the discrimination bit position of branch nodes traversed in the search path, is stored in the search path stack.

Abstract: A bit string searching apparatus has a coupled node tree, having a root node and a node pair, the node pair being a branch node and leaf node, or a pair of branch nodes, or a pair of leaf nodes in adjacent storage areas, the branch node including a search key discrimination bit position and information indicating a position of one node of a node pair of a link target, and the leaf node including an index key that is a bit string that is the target of a search, wherein a search for an index key from the root node to a branch node using a search key is executed by repeatedly and successively linking to one node of a node pair of a link target, according to a bit value of a search key at the discrimination bit position in the branch node, until reaching the leaf node.