| 摘要 |
PROBLEM TO BE SOLVED: To back up a database online, while keeping consistency for a plurality of applications.SOLUTION: Database I/O units 30 control read/write from/to a database 20 from corresponding application 10a or 10b. When an instruction for online backup is issued, a status of each database I/O unit 30 in a status management unit 32 becomes "restriction being requested". The database I/O unit 30 which is in the "restriction being requested" accepts an update instruction to the database 20 until an update confirmation instruction is received from the application 10 for sessions which already have started update. After the update confirmation instruction is received, a new update instruction is not accepted for the session. After all database I/O units 30 become the status in which the update instruction is not accepted for all sessions, an online backup trigger unit 34 instructs an online backup unit 22 to start processing. |
