Getting Started with IBM Data Studio for DB2

Chapter 3 – Maintaining the database 105
When a query runs, the DB2 system fetches the required data into main memory for
processing. The memory areas used to fetch the data from storage are called buffer pools.
Again, because the performance requirements of tables and applications can differ, you
may wish to have more control over memory usage by different tables.
This section will define these storage and memory areas and explain how you can create
and work with them.
3.2.1 Creating and managing table spaces
A table space is a logical database object that maps the logical objects like tables, indexes,
and so on, to the physical storage memory. It consists of containers, which could be an
operating system file, directory, or a raw device. In this section, we will concentrate on files
and containers. Raw devices, although supported, are not widely used in a typical
database due to advances in disk and file system performance.
A DB2 data server can have multiple types of table spaces depending on how the memory
is managed and how the containers are defined:
A system-managed table space is managed by the operating system and can have
directories as its containers.
A database-managed table space is managed by the database manager and can have
files and raw devices as its containers.
An automatic storage table space is the alternative system-managed and databasemanaged
storage in which DB2 itself manages the containers. You just need to specify
the path where the containers should be created and the maximum size that the DB2
server can use for these containers.
A table space can also be categorized based on the type of data it stores–regular, large, or
temporary.
3.2.1.1 Creating a table space
To create a table space by using Data Studio:
1. Right-click the Table Spaces folder and select Create Regular Table Space, as
shown in Figure 3.2.