Patent ID: 7421456
Filing Date: 2008-09-02
Classification: G06F

Abstract:
1. A method of reorganizing a database which is stored in a disk drive of a storage device and which is accessed by a host computer, the disk drive containing a first volume where the database is stored and a second volume paired with the first volume to store a copy of the database, the method comprising the steps of: making a transaction of the host computer into a quiescent state; splitting the paired first volume and second volume, wherein the database is able to be accessed in the first volume but not the second volume; releasing the quiescent state of the transaction; reorganizing the second volume by copying and reorganizing data of the second volume into an unloading volume in the storage system; copying the reorganized data from the unloading volume to the second volume; updating the second volume using log data; and copying the reorganized and updated data in the second volume to the first volume to resynchronize and pair the first volume and the second volume with each other, wherein the disk drive further contains a third volume to store a log of the log data which is made when the database is accessed, and a fourth volume as the unloading volume where a copy of the data of the database stored in the second volume is stored, and wherein the step of reorganizing the second volume comprises the steps of: reorganizing data of the database which is stored in the second volume and copying the reorganized data to the fourth volume; initializing the second volume after completion of copying the reorganized data to the fourth volume; restoring the reorganized data of the database which is stored in the fourth volume to the second volume; obtaining, from the third volume, logs which are entered after the quiescent state of the transaction is released; and reflecting the logs on the reorganized data of the database which is stored in the second volume.