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

• US 20080163237A1
• Filed: 02/27/2008
• Published: 07/03/2008
• Est. Priority Date: 01/09/2004
• Status: Active Grant

• Current Assignee: Daisuke Ito, Frederico Buchholz Maciel, Kazutomo Ushijima, Shinji Fujiwara
• Original Assignee: Daisuke Ito, Frederico Buchholz Maciel, Kazutomo Ushijima, Shinji Fujiwara
• Inventors: Ito, Daisuke, Fujiwara, Shinji, Ushijima, Kazutomo, Maciel, Frederico Buchholz
• Granted Patent: US 8,041,685 B2
• Time in Patent Office: Days
• US Class Current: 718/104
• 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 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 storage to respective backend modules by registering mapping information between the data regions and the backend modules;

determining whether or not a CPU resource is to be removed from the shared-nothing database management system by monitoring the stats of the plurality of CPU resources;

in response to the determination that the CPU resource is to be removed, delegating a data region previously allocated to a backend module corresponding to the CPU resource to be removed to another backend module; and

relocating to respective backend modules except the backend module corresponding to the CPU resource to be removed by changing the mapping information.

2. 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 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 storage to respective backend modules by registering mapping information between the data regions and the backend modules;

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; and

in response to the determination that the storage I/O resource is to be added, relocating to respective backend modules including said added backend module by changing the mapping information.