Data update system, navigation apparatus, and data update method

A navigation apparatus operated in accordance with a predetermined operation program while accepting a difference data file for updating a database from a server apparatus, comprising:

• a local storage database containing data in an update data format that is different from a referential data format used in execution of the operation program, the local storage database being updated by the difference data file;
• priority determination means for, after updating the local storage database, determining a conversion priority for a plurality of data groupings stored in the local storage database in accordance with state of operation of the operation program;
• and
• conversion means for converting data stored in the local storage database to the referential data format in the order of the conversion priority.

A data update method for updating a database by providing a difference data file from a server apparatus to a navigation apparatus, the navigation apparatus having a local storage database containing data in an update data format that is different from a referential data format utilized in execution of an operation program, wherein the method comprises:

• outputting the difference data file from the server apparatus to the navigation apparatus;
• and
• at the navigation apparatus:
• accepting the difference data file;
• updating the local storage database with the difference data file;
• determining, after updating the local storage database, a conversion priority for a plurality of data groupings stored in the local storage database according to state of operation state of the operation program;
• converting data stored in the local storage database to the referential data format in the order of the conversion priority, thus making the converted data available for use in execution of the operation program.