US 7,487,162 B2
Method and data processing system with data replication
Kenichi Kitamura, Yokohama (Japan); Mitsuo Miyazaki, Zushi (Japan); Kota Yamaguchi, Yamato (Japan); and Hiroshi Yamakawa, Yokohama (Japan)
Assigned to Hitachi, Ltd., Tokyo (Japan); and Hitachi Software Engineering Co., Ltd., Yokohama-shi (Japan)
Filed on Feb. 20, 2004, as Appl. No. 10/781,677.
Claims priority of application No. 2003-108361 (JP), filed on Apr. 11, 2003.
Prior Publication US 2004/0215637 A1, Oct. 28, 2004
Int. Cl. G06F 7/00 (2006.01)
U.S. Cl. 707—100  [707/202] 3 Claims
OG exemplary drawing
 
1. A data processing method comprising steps of:
copying data from a first database to a second database while allowing access to the first database by a program during the copying, such that the second database is a duplicate of the first database as a result of the copying;
as a result of an input designating reorganization of the first database, switching a program access allowance from the first database to the second database and allowing the program to access the second database in place of the access to the first database;
after switching the program access allowance, storing a history of a processing of the program to the second database as a processing history and executing the reorganization of the first database in parallel with the accessing of the program to the second database, the processing history being stored during the execution of the reorganization, and the processing history being stored on a storage system in which the first database and the second database are stored;
upon completion of the reorganization of the first database, updating the first database based on the processing history stored during the reorganization;
upon completion of the updating of the first database based on the processing history stored, switching the program access allowance from the second database to the first database and allowing the program to again access the first database in place of the access to the second database;
determining whether access to the first database in a replica operation mode is allowed for the program seeking the access, based on a condition of a replica operation of the first database; and
if it is determined that access to the first database in a replica operation mode is allowed for said program, executing said access to the first database in the replica operation mode in parallel with the accessing of the program to the second database, but if it is determined that access to the first database in a replica operation mode is not allowed for said program, causing an error and disabling access to the first database;
wherein the replica operation mode is a mode in which the program access allowance has been switched from the first database to the second database;
wherein said step of determining whether access to the first database in a replica operation mode is allowed includes a step of reading a dynamic access allowance flag from a table using the name of the program seeking the access as a key; and
wherein the access allowance flag indicates whether access to the first database is allowed for the program seeking the access.