| 摘要 |
PURPOSE: To attain page division in both horizontal and vertical directions for processing page overflow. CONSTITUTION: A multidimensional B tree for storing data has a buried 'master/ slave' structure for allowing a sub-tree to be included in a node, and the sub- tree includes sub-nodes 34 and 35 which can include the sub-tree. A node 30 is indexed by a main key value, and the sub-node of the sub-tree is indexed by a second-dimensional key value. The node of the multidimensional B tree includes a key value chart, sub-node chart, and data area. When a tree manager stores the unit of the data in a page, and the data are too large for the page, the node stored at present in the page is divided into the sub-nodes and the sub-tree in trial. When the unit of the data can not divided into the sub-nodes and the sub-tree, more than one node stored at present in the page are moved to a new page.
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