| 摘要 |
PURPOSE:To make the regeneration of indexes unnecessary even if lengths and attributes of data items are changed, by generating a key of indexes by a prescribed encoding system. CONSTITUTION:In respect to indexes of an index part 1, plural numeric data items which become a key are extended to double-word binary data items respectively, and encoded binary data obtained by encoding these binary data items are linked by the multifield linking technique. The key obtained by linkage includes a forward/backward compressed key. This key is compressed forward or backward in a forward/backward compression expanding routine 2 to expand the compressed key to its original form. Input data items i1-i3 are encoded in an encoding routine 3 and are linked by the multifield linking technique to output a link key (k). The key from the routine 2 and the key (k) are compared with each other; and if they coincide with each other, a data item pointed by the index for coincidence is outputted. |
