| 摘要 |
PURPOSE: To improve operability and increase compression efficiency by eliminating the inconvenience (unnecessary selection and poor compression because of data compression on a town and village level) that tree structure as a conventional example has when place name data is retrieved according to a zip code. CONSTITUTION: In a character string table 105, high-frequency character strings among character strings constituting place name data are registered. Character string indexes 104 have the high-frequency character strings numbered through painters. A zip code dictionary main body 103 represent each place name data as a combination of the number of the high-frequency character string and the individual place name, and repetitive place name data is registered in an omitted state. The pointer of the high-order two digits of a zip code is allocated to a primary index 101, a secondary index 102 to which the low-order three digits of the zip code are allocated is generated with the pointer, and the pointer to the zip code dictionary main body 103, the number of place name data constitution characters, and the number of repetitive characters are allocated. |
