Geographic information indicator, method for displaying geographic information and storage medium for storing program for executing the same

A geographic region indicator for displaying geographic information obtained via a network from a remote database server that stores said geographic information as a map and facilities to be arranged on said map, comprising:

• a local database for storing data obtained from said database server as a result of an inquiry;
• screen display request input device configured to input a screen display request range in a form of a rectangular range;
• means for storing a plurality of effective ranges each having corresponding data stored in said local database, said effective ranges overlapping and corresponding to rectangular ranges of said map;
• local database effective range check device configured to decide at least one of first and second rectangular ranges of said map within said screen display request range, said first range having corresponding data already stored in said local database and said second range having corresponding data not stored in said local database;
• server-side database retrieval request device configured to retrieve, from said remote database server via said network, said data corresponding to said second rectangular range based on a decision result of said local database effective range check device;
• local database update device configured to store the data corresponding to the second rectangular range and obtained as a retrieval result in said local database, and also update said effective range in said local database effective range information to include an effective range corresponding to said rectangular range;
• local database retrieval device configured to extract total data associated with said rectangular range, including the data corresponding to said first area and the data corresponding to said second area, from said data stored in said local database;
• and
• screen display device configured to display said total data extracted from said local database on a screen.

A program storing medium readable by a computer, tangibly embodying a program of instructions executable by said computer to perform method steps for a geographic region indicator for displaying data stored in a local database, which is obtained via a network from a remote database server that stores geographic information as a map and facilities to be arranged on said map, said method comprising the steps of:

• a screen display request input step for inputting a screen display request range;
• a step for storing a range having corresponding data stored in said local database in a form of a local database effective range information, said range corresponding to an area of said map;
• a local database effective range check step for deciding at least one of first and second areas of said map within said screen display request range, said first area having corresponding data already stored in said local database and the second area having corresponding data not stored in said local database based on said local database effective range information;
• a server-side database retrieval request step for retrieving, from said remote database server via said network, said data corresponding to said second area based on a decision result of said local database effective range check step;
• a local database update step for storing said data corresponding to the second area and obtained as a retrieval result in said local database and also updating said local database effective range information to include an effective range corresponding to said second area;
• a local database retrieval step for extracting total data included in said screen display range necessary for screen display including the data corresponding to said first area and the data corresponding to said second area;
• from said data stored in said local database;
• and
• a screen display step for displaying said total data extracted from said local database on a screen.

A method for indicating geographic region to supply a user data stored in a local database, which is obtained via a network, from a remote database server that stores geographic information as a map and facilities to be arranged on said map, said method comprising the steps of:

• a step for urging said user to input a screen display request range;
• a step for storing a range having corresponding data stored in said local database in a form of a local database effective range information, said range corresponding to an area of said map;
• a step for deciding at least one of first and second areas of said map within said screen display range, said first area having corresponding data already stored in said local database and the second area having corresponding data not stored in said local database based on said local database effective range information;
• a step for retrieving, from said remote database server via said network, said data corresponding to in said second area based on a decision result;
• a step for storing said data corresponding to the second area and obtained as a retrieval result in said local database and also updating said local database effective range information to included effective range information corresponding to said second area;
• a step for extracting total data included in said screen display range necessary for screen display including the data corresponding to said first area and the data corresponding to said second area, from said data stored in said local database;
• and
• a step for transmitting said total data extracted from said local database to a terminal of said user.