Altering a buffer pool

Authorities and privileges

To alter a buffer pool:

1. Open the Alter buffer pool window.

2. Place your cursor in the field you want to change. The fields on this window relate to sizes and thresholds of the buffer pool or hiperpool.

3. Type a valid number that reflects the new size. Each field has a range from 0 to some number of kilobytes. The exception is for BP0, which requires a minimum of 56KB. If you set Virtual buffer pool size to 0 for an active buffer pool, you have deleted the buffer pool. DB2 for OS/390 quiesces all current database access and fails all subsequent page set open requests.

4. Repeat the above 2 steps for any additional fields that you want to change.

5. In the Vertical deferred write buffer pool field, the size you specify can be expressed as a percentage of total buffer pool size, or as an absolute number. Select the radio button that defines the format of VDQT.

6. Select one of the following Discard hiperpool data radio buttons:

   Yes

   MVS discards the data cached in the hiperpool when a shortage of expanded storage arises.

   No

   MVS assigns a high priority to keeping the data cached in the hiperpool. You should select No only for buffer pools associated with databases for which response time is critical.

7. In the Page stealing algorithm radio buttons, specify if you want DB2 to manage the buffer pool buffers for page stealing with the Least recently used algorithm (LRU) or the First-in-first-out algorithm (FIFO).

8. Click OK to apply the change and close this window.

Related information

• Buffer pool concepts

• CASTOUT