application or a user connects to a specified database to read or manipulate 

data in tables.

Figure 1 5 shows the relationship between instances, databases, and tables.

Server system

User,

Application

Database Manager 

I

I

ns

n

t

st

an

a

c

n

e

ce

...

...

I

I

ns

n

t

st

an

a

c

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ce

Instances

connect to

...

Databases

...

...

Tables

...

Figure 1 5   Relationship between instances, databases, and tables

Database partition groups

A database partition group is a set of one or more database partitions 

(Figure 1 6). Before creating tables for the database, you first need to create 

the database partition group where the table spaces will be stored, and then 

create the table space where the tables will be stored. If a partition group is 

not specified, there is a default group where table spaces are allocated. In 

earlier versions of DB2, database partition groups were known as 

nodegroups

. In a non partitioned environment, all the data resides in a single 

partition, therefore it is not necessary to worry about partition groups.

12 

MySQL to DB2 UDB Conversion Guide