| 摘要 |
PROBLEM TO BE SOLVED: To swiftly acquire a piece of information in a specified space range.SOLUTION: A space search tree storage stores a space search tree; each of terminal nodes is associated with a piece of attribute information of an object; and a host node is associated with a piece of aggregation attribute information which is generated according to the attribute information of all of lower terminal nodes. A search controller performs recursive search from a root node toward lower nodes of the space search tree on the basis of a search range, in which a part of the space is specified, to search a node to which an external envelope rectangular solid overlapping with the search range is allotted. When the node detected by the search controller is a first node that does not satisfy prescribed search conditions, a pruning section determines not to perform the search of nodes lower than the first node. The output section outputs a search result on the basis of the aggregation attribute information of the first node and the attribute information of the terminal node detected by the search controller. |
