Defining or allocating a buffer pool
Use the Define Buffer Pool window to allocate a buffer pool as an
active virtual buffer pool.
Authorities
and privileges
To define or allocate a buffer pool:
-
Open the Define Buffer Pool window.
-
Specify a buffer pool from the list of undefined or inactive buffer pools.
A buffer pool is named sequentially and for its page size. BP0 - BP49 use
4 KB buffers. BP8K0 - BP8K9 use 8 KB pages. BP16K0 - BP16K9 use 16 KB pages.
BP32K - BP32K9 use 32 KB buffers.
-
Type a valid number in any of the fields that you want to set thresholds
or sizes. The fields in this window relate to sizes or thresholds of a
buffer pool or hiperpool . Each
field has a range from 0 to some number of kilobytes. The exception is
for BP0, which requires a minimum of 56 KB. If you set Virtual buffer pool
size (VPSIZE) to 0 after
you activate the buffer pool, you will delete the buffer pool. DB2 for
OS/390 quiesces all current database access and fails all subsequent page
set open requests.
-
Repeat step 3 for any additional fields that you want to define a threshold.
-
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.
-
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.
-
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).
Click OK to apply the threshold and size values and close this
window.
Related information