| 摘要 |
PURPOSE:To process a sort request in descending and ascending orders at a high speed by installing a pointer capable of pointing data in right and left directions between nodes of the same depth on an index of a tree structure. CONSTITUTION:The titled system is of an index model having a tree structure, and formed with a route page 1, an index page 2, leaf pages 3-5 and data 7 and 8 of one line on a table, which include a key value. In order to attain the retrieval in descending and ascending orders by such an index, the pointer capable of pointing in both directions is given between nodes on pages having the same depth. Owing to the installation of the pointer, data can be obtained by specifying one index key value, and the result sorted in the ascending or descending order can be obtained with the use of the index having the tree structure.
|
