DATABASE STRUCTURE CHANGING METHOD, CONTROL METHOD OF DATABASE ACCESS REQUEST, ONLINE SYSTEM, STORING MEDIUM STORING DATABASE OPERATION SUPPORTING MIDDLEWARE AND STORING MEDIUM STORING SHIFTING UTILITY

摘要

PROBLEM TO BE SOLVED: To enable maintenance operation such as the structure change of a database without stopping an online system. SOLUTION: In order to access to a DB, from an application job program 230, the name of the DB is not designated directly but the name of a file is designated. A DB operation supporting middleware 220 manages the name of the DB corresponding to this name of the file and transfers access from the program 230 to the DB corresponding to the name of the file. A DB (copy DB) 215 after change of structure is generated in addition to the DB (original DB) 210 before the change of structure and the name of the DB is related with the file name of the original DB. Next, data of the original DB is copied in the copy DB for each record. In the case where online access occurs during copying, whether a record given an access request is before or after copying is judged to sort the access request.