METHOD FOR READING DATA, DATA MANAGEMENT SYSTEM, AND STORAGE SYSTEM

摘要

PROBLEM TO BE SOLVED: To provide a database management system for issuing an optimal data read request in data location occurring while dynamic data migration inside a storage system. SOLUTION: The database management system obtains storage mapping information which associates addresses in a plurality of physical storage devices within the storage system and addresses in logical storage devices comprising these physical storage devices to create queues individually for the respective plurality of physical storage devices. The database management system receives a plurality of read requests which request data to be read out of the physical storage devices via the logical storage devices provided by the storage system and accumulates the read requests in the respective queues corresponding to the request destination physical storage devices. The database management system reorders a plurality of the accumulated read requests in order that shortens a total sum of the data read time in each physical storage device and issues the requests to the storage system. COPYRIGHT: (C)2009,JPO&INPIT