Maintaining Tablespaces (DB2 UDB for UNIX and
Windows) 
Use
Using the tablespace list on the Space: Tablespace Configuration screen, you can maintain tablespace entries as follows:
· Change tablespace settings and containers
· Add new tablespaces
· Delete tablespaces
Procedure
Changing Tablespaces
...
1.
On the Space: Tablespace Configuration screen,
choose 
Change.
The Space: Tablespace Maintenance – Change Tablespace screen appears.
The following information is displayed:
|
Field |
Description |
|
Tablespace Maintenance |
|
|
Partition |
Currently selected partition (node) where the tablespace is defined. The value displayed is only higher than 1 if you are using a multi-partition database. |
|
Name |
Name of tablespace |
|
Node Group |
Name of node group where the selected tablespace is defined. A node group defines a set of partitions. |
|
Space |
|
|
Total |
Total space in KB. This information is not displayed when creating tablespaces. |
|
Used |
Fill level of the selected tablespace as a percentage. This information is not displayed when creating tablespaces. |
|
Free |
Free space in KB. This information is not displayed when creating tablespaces. |
Technical Settings
The following are fixed values that cannot be changed:
|
Field |
Description |
|
Contents |
Describes, which kind of data will be stored in the tablespace, for example, regular data, large objects, temporary user objects or temporary system objects. |
|
Space Management by |
Describes, whether the tablespace is simply stored in a directory and the space management is done by the file system (SMS) or if the database itself manages the tablespace space (DMS). |
|
Size of I/O Units |
|
|
Page Size |
Page size in KB |
|
Extent Size |
Extent size in KB |
You can enter values in the following fields:
|
Field |
Description |
|
Size of I/O Units |
|
|
Prefetch Size |
Number of pages to be prefetched |
|
Disk Performance |
|
|
Overhead |
Displays I/O controller overhead and disk seek and latency time in milliseconds. This value is used to determine the cost of I/O during query optimization. |
|
Transfer Rate |
Time to read one page into memory in milliseconds. This value is used to determine the cost of I/O during query optimization. |
|
Recovery |
|
|
Dropped Tables |
Dropped tables in the specified tablespace may be recovered using the RECOVER TABLE ON option of the ROLLFORWARD command. |
For more information on the technical settings, see the IBM documentation SQL Reference.
Containers
You can add or delete containers:
¡
To add containers, choose
Add.
The system automatically suggests a default path where the container is located. However, you can modify that path by manually editing the line.
Adding or changing containers might result in rebalancing, which has a heavy impact on system performance.
At least one container must be available for each partition. If you are using a multi-partition database, you need to add containers for all partitions of the corresponding node group.
If you have to change container sizes, we recommend that you use Resize all containers to to ensure a balanced distribution of data on the different containers.
Different container sizes might result in bad performance of the database.
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To delete containers,
select one or more lines in the table and choose
Delete.
2. To apply changes, choose either Technical Settings or Containers.
3.
To confirm your entries,
choose 
Execute.
Adding Tablespaces
...
1.
On the Space: Tablespace Configuration screen,
choose Add.
The Space: Tablespace Maintenance – Add Tablespace screen appears.
2. Specify a name and a node group.
We recommend that you use uppercase letters for the tablespace name. Using lowercase letters or special characters makes accessing the selected tablespace with the DB2 command line processor less comfortable.
3. Enter the technical settings. By default, the system displays SAP's recommendations.
4. Add containers.
If you are using a multi-partition database, you must add containers for all partitions of the corresponding node group.
5.
To confirm your entries,
choose Add.
Deleting Tablespaces
...
1. On the Space: Tablespace Configuration screen, select a tablespace.
2.
Choose Delete.
The Space: Tablespace Maintenance – DeleteTablespace screen appears.
3.
To delete the selected
tablespace, choose Delete.
You cannot delete tablespaces that are still used by the SAP system, that is, if they are related to some data class.
You must delete the data class before deleting the tablespace.
SQL Statements
In the lower half of the Space: Tablespace Configuration screen, an editor is displayed that shows the generated SQL statement(s) that will be executed. This area is automatically filled and refreshed if any changes were applied correctly.
See also: