| 摘要 |
PROBLEM TO BE SOLVED: To provide a disaster recovery (DR) technique capable of attaining reduction in equipment cost and further easy operation. SOLUTION: In the DR system, from a standpoint of equipment cost, a physical application capable of log recovery by an inexpensive DB appliance server 400 is adapted when no retrieval is performed. Further, local mirror operation in a sub-site is not performed. From an operational standpoint, the tendency of log application or operation is monitored, and retrieval processing is received according to the progress of log application. When the log application in the sub-site cannot sufficiently catch up, retrieval is not received. Further, when the matching property of a sub-DB is ensured, transactions Tr in progress at the time of retrieval instruction are not undone, but redo processing is performed only to the Tr in progress at the time of retrieval instruction. COPYRIGHT: (C)2008,JPO&INPIT
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