Performance Tuning for Content Manager

20 Performance Tuning for Content Manager

2.1 DB2 Universal Database overview

Library Server uses a relational database, and Resource Manager also uses a

relational database. IBM DB2 Universal Database (DB2) is a multimedia,

Web-ready, relational database management system (RDBMS). It is available on

z/OS, UNIX®, Windows, and AS/400® platforms. Understanding DB2 is critical

to achieving success in performance tuning for Content Manager systems.

There are many well-written publications on DB2 that contain very useful

information. Most of the material presented in the following sections is extracted

from these publications:

 IBM DB2 Universal Database Version 8.2 Administration Guide: Planning,

SC09-4822

 IBM DB2 Universal Database Version 8.2 Administration Guide: Performance,

SC09-4821

 IBM DB2 UDB V8 and WebSphere V5 Performance Tuning and Operation

Guide, SG24-7068

We include what we think is important to give you a quick start in the basic

concepts of DB2, as well as aspects of performance tuning for the DB2 database

system and routine maintenance that should be performed. For a more in-depth

understanding of DB2, we recommend that you read these publications because

they proved to be extremely helpful for us.

2.1.1 Basic DB2 database concepts

In this section, we introduce some of the basic relational database concepts. This

includes an overview of the various database objects and the database

configuration files.

Database objects

Database objects are the components that make up a DB2 relational database.

Some of the more important database objects are: instances, databases,

database partition groups, tables, views, indexes, schemas, system catalog

tables, buffer pools, table spaces, containers, and stored procedures.

Figure 2-1 on page 21 displays the database objects relationship. The individual

components of the database objects will be discussed throughout this section.

Chapter 2. Content Manager base products 21

Figure 2-1 Database objects relationship

Instances (database managers)

An instance (also known as a database manager) is DB2 code that manages

data. It controls what can be done to the data, and manages system resources

that are assigned to it. Each instance is a complete environment. If the database

system is parallel, it contains all of the database partitions. An instance has its

own databases (which other instances cannot access), and all its database

partitions share the same system directories. It also has separate security from

other instances on the same machine or system.

Databases

A relational database presents data as a collection of tables. A table consists of a

defined number of columns and any number of rows. Each database includes a

set of system catalog tables that describe the logical and physical structure of the

data, a configuration file containing the parameter values allocated for the

database, and a recovery log with ongoing transactions and transactions to be

archived.

System

Database

Database partition group

Table spaces

Tables

Indexes

Long data

Instance