Abstract: A data retrieval method and apparatus in a distributed database system. Data is retrieved from a distributed database quickly with a minimum load on each terminal. A contents file is provided in each terminal, and a link file is provided in a center system to coordinate access to the distributed data in each terminal.

Abstract: The system provides a data storage system program 18 between a user and a physical memory device 14 which stores file records 20. The data storage system 18 stores records as linked record segments 40/51 that can be randomly located within the memory storage device 14. The segments 40/51 are linked by a next segment address found in a next segment address field 50/56 of a record segment 40/51. When a record needs to be expanded and the current record segment 1000 is not large enough to accommodate the expansion, another record segment 1082 is allocated and used. If variable length record segments 40 are used, only a single record extension is required. However, if fixed length record segments 50 are used, the system allocates sufficient fixed length record segments to store the additional data.

Abstract: In a network control system connecting terminal units providing at least a chat function to make communication with the other terminal units on a real time basis while connecting the keyboard and executing mutual communication between the terminal units, the terminal unit which becomes the transmitting side describes the mode corresponding to the function to be executed and sets a communication code corresponding to such mode within a communication command to be transmitted. The transmitting terminal indexes a connection timing table and also connects or disconnects the line for communication to the distant terminal unit on the basis of contents of the connection timing table in order obtain cost-effective application of the communication network.

Abstract: The present invention is a system that converts a vertical file (28) of time series data records from multiple terminals (10-14) and stored by time into a horizontal file (52) where records are organized by terminal (10-14). The user can then access the desired terminal information rapidly in the horizontal file (52) rather than having to perform an inefficient sequential search of the vertical file (28). After the terminal data is horizontally stored, the data is used to create display or print-out windows of the terminal data for many locations. Each window includes the data from a single terminal (10-14). For example, each window could include a graph of rain data for a location. The system also creates a cross reference table (76) of the addresses of the data used to create each window.

Abstract: A distributed data base system is formed by terminal units connected in a public network or a private network. Each terminal unit stores respectively the real data and a temporary center for storing the one or a plurality of control information among various pieces of control information, such as contents corresponding to each real data, keyword or command assigned to data. Moreover, check information set up for acquiring security is provided as the one of the terminal unit. A terminal unit utilizing data obtains identification information of terminal units storing relevant real data by inputting contents, commands or keywords by accessing the center and reading or extracting the necessary real data through the network from a terminal unit having real data based on such identification information but is capable of restricting users (terminal units) which are allowed to read the open data in accordance with the degree of importance of the data.