Method of changing system configuration in shared-nothing database management system

• US 7,370,029 B2
• Filed: 04/30/2004
• Issued: 05/06/2008
• Est. Priority Date: 01/09/2004
• Status: Expired due to Fees

• Current Assignee: Avago Technologies General IP PTE Limited (Broadcom, Inc.)
• Original Assignee: Hitachi, Ltd.
• Inventors: Ito, Daisuke, Fujiwara, Shinji, Ushijima, Kazutomo, Maciel, Frederico Buchholz
• Primary Examiner(s): Lee; Wilson
• Application Number:
  US10/835,073
• Publication Number:
  US 20050154731A1
• Time in Patent Office: 1,467 Days
• Field of Search: 709/203, 709220-222, 709226-229, 707 1- 10, 707/100, 707/101, 707/102
• US Class Current: 707/752
• CPC Class Codes: G06F 16/284 Relational databases
• CPC Class Codes: Y10S 707/99932 Access augmentation or optimizing
• CPC Class Codes: Y10S 707/99943 Generating database or data structure, e.g. via user interface

Abstract

A shared-nothing database management system employs a method of adding and removing a database server without significantly affecting the processing performance for accessing a table from a user or an application. A scheduler module creates a schedule which separately handles the addition of a CPU resource and the addition of a storage I/O resource, and a server is added in accordance with the created schedule. A common disk is used to remove a disk at an arbitrary timing. Further, a data region is previously subdivided on the common disk to eliminate a movement of data associated with the addition of a server.

Claims

1. A system configuration changing method in a shared-nothing database management system which includes a plurality of CPU resources, a storage, and a network for connecting said CPU resources and said storage, wherein each of said plurality of CPU resources runs a database search program stored in a computer readable medium being executable by a processor so that each functions as a backend module for processing data, said method comprising the steps of:

allocating physically independent data regions of the storaae to respective CPU resources by a mapping module;

adding to said shared-nothing database management system a backend module exclusively for sorting and merging data without accessing a table in a database, wherein the added backend module sorts and merges data by receiving the data from other backend modules that have read the data from said storage;

determining whether or not a storage I/O resource is to be added to said backend module exclusively for sorting and merging data;

changing said backend module exclusively for sorting and merging data to an ordinary backend module for accessing a table in a database in response to a determination that the storage I/O resource is to be added; and

relocating data after a load on a group of active backend modules is reduced to a system-defined value or a user-defined value in response to the determination that the storage I/O resource is to be added.