Database

Database 

Database 

Database

Partition

Partition

Database

Partion Group 2

Partion Group 1

Database 

Partition

Database 

Partition

Database

Partion Group 3

Database 

Partition

Figure 1 6   Database partition groups in a database

System catalog tables

Each database includes a set of system catalog tables, which describe the 

logical and physical structure of the data. DB2 UDB creates and maintains an 

extensive set of system catalog tables for each database. These tables 

contain information about the definitions of database objects such as user 

tables, views, and indexes, as well as security information about the privilege 

that users have on these objects. Catalog tables are created when the 

database is created, and are updated during the course of normal operation. 

You cannot explicitly create or drop them, but you can query and view their 

contents using the catalog views.

Table spaces

A database is organized into subdivided table spaces. A table space is a 

place to store data. When creating a table, you can decide to have certain 

objects such as indexes and large object (LOB) data kept separately from the 

rest of the table data. A table space can also be spread over one or more 

physical storage devices. 

 Chapter 1. Introduction 

13