Variable-length database apparatus and method for accessing the same

摘要

A variable-length database apparatus capable of performing addition, change or the like of data without reconstructing a database in the event of attempting to change the database in accordance with the items of a table or the change of specifications of a record. The database apparatus is provided with an inputting portion for inputting stored data. It also has a retrieval condition, a database for storing data inputted by the inputting portion, a database management system for reading and writing data from and to the database, and an outputting portion for outputting the result of retrieving data stored in the database. The database includes: (1) an item definition area for storing, and relating to each other, the item name, data type and item length of each item defined in said database, and the packet number given to the item of data; (2) a record management area for giving a packet number to a record consisting of items defined by the item definition, and for storing and relating to each other those packet numbers; (3) a data area for storing items of data; (4) an extracting means for extracting, when data inputted by said inputting portion and data in the record management area are matched with a retrieval condition in retrieval of data, the matched data from said data area; and (5) an outputting means for outputting the data extracted by the extracting means.