Maintaining Buffer Pools (DB2 UDB for UNIX and Windows) 

Use

Using the buffer pool list on the Configuration: Buffer Pools screen, you can maintain buffer pool entries as follows:

·        Change buffer pools, that is add or remove partitions, resize or control the use of extended storage

·        Add new buffer pools

·        Delete buffer pools

Procedure

Changing Buffer Pools

...

       1.      On the Configuration: Buffer Pools screen, choose  Edit.

The Configuration: Buffer Pool Maintenance – Change Buffer Pool screen appears.

The following information is displayed:

Technical Settings

This tabstrip provides a set of all technical attributes:

Column	Description
Partition	Partitions that have been defined for the selected buffer pool. The list depends on the selection of node groups. You can modify the size of the buffer pool on selected nodes or set the size for all nodes by using the field Set size on all nodes to.
Buffer Pool Size (Pages)	Buffer pool size in pages
Immediate	Indicates that the buffer pool is created immediately and not after the next system restart.

 

Field	Description
Set size of all nodes to... (Pages)
Page Size	Size of one page in the buffer pool
Block Size	Size of one block for blocked I/O in pages – displayed only if you are using DB2 Version 8
Number of Block Pages	Number of pages that are reserved for block I/O usage – displayed only if you are using DB2 Version 8
Use extended storage	Indicates whether extended storage is used or not. This option is only effective if the database configuration parameters NUM_ESTORE_SEGS and ESTORE_SEG_SIZE are set to non-zero values.

 

Node Groups

This tabstrip contains a list of all node groups to which the buffer pool is related. A buffer pool can be related to all available nodes or to a set of nodes defined by node groups. If the buffer pool is not already defined on all nodes, you can select further node groups.

For detailed information on node groups, double-click the corresponding node group.

For more information on node group maintenance, see Maintaining Node Groups.

Tablespaces

This tabstrip contains a list of all tablespaces that use this buffer pool.

Column	Description
Tablespace Name	Name of the tablespace
Page Size	Size of one tablespace page in bytes

For detailed information on tablespaces, double-click the corresponding tablespace.

For more information on tablespace maintenance, see Maintaining Tablespaces.

       2.      To apply changes, choose Technical Settings or Node Groups.

       3.      To confirm your entries, choose  Execute.

Adding Buffer Pools

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       1.      On the Configuration: Buffer Pools screen, choose  Add.

The Configuration: Buffer Pool Maintenance – Add Buffer Pool screen appears.

By default, all available partitions are listed to be related to the new buffer pool. If you want to reduce this list, go to the Node Groups tabstrip and select option On Selected Node Groups and choose node groups from the list.

       2.      Specify a name for the new buffer pool.

We recommend that you use uppercase letters for the buffer pool name. Using lowercase letters or special characters makes accessing the selected node group with the DB2 command line processor less comfortable.

       3.      Enter the technical settings such as the page size.

       4.      To confirm your entries, choose  Add.

Deleting Buffer Pools

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       1.      On the Configuration: Buffer Pools screen, select a buffer pool.

       2.      Choose  Delete.

The Configuration: Buffer Pool Maintenance – Delete Buffer Pool screen appears.

       3.      To delete the selected buffer pool, choose  Delete.

SQL Statements

In the lower half of the Configuration: Buffer Pool Maintenance 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.