DB2 Server for VSE & VM: Operation

COUNTER POOL

Displays the number of occurrences of key events by storage pool. Also displays counters for the directory and unmapped internal dbspaces.

Syntax

>>-COUNTER POOL----+-*--------+-------------------------------->< +-n--------+ +-DIR------+ '-UNMAPPED-'

*

Displays counters for all storage pools, the directory, and unmapped internal dbspaces.

n

Displays counters for storage pool number n. Valid values are integers from 1 to 999.

DIR

Displays counters for the directory.

UNMAPPED

Displays counters for unmapped internal dbspaces.

Description

Storage Pool Counters

The COUNTER POOL command displays two sets of counters. One set is for storage pools using Data Spaces Support, a directory that uses Data Spaces Support, and unmapped internal dbspaces. The other set is for pools using the standard DASD I/O system and a directory using the standard system.

The counters for the standard I/O system are:

LBUFLOOK

The number of times the database manager has looked into the local data page buffers.

PGREAD

The number of pages moved from DASD to the local buffers.

PGWRITE

The number of pages moved from the local buffers to DASD.

IUCVBIO

The number of IUCV *BLOCKIO requests submitted by the database manager to the operating system. Note that, because the database manager often uses one IUCV *BLOCKIO request to write several pages at one time, IUCVBIO is usually lower than PGREAD+PGWRITE.

The counters for Data Spaces Support are:

LBUFLOOK

The number of times the database manager has looked into the local data page buffers.

DSREAD

The number of pages moved from the VM data spaces to the local buffers.

DSWRITE

The number of pages moved from the local buffers to the VM data spaces.

DSFAULT

The number of pages, requested from data spaces, that the operating system did not find in main or expanded storage. These page faults cause the operating system to read the pages from DASD in to the data spaces in main storage.

Example

This example shows a database where the directory and the first storage pool are using Data Spaces Support, the second pool is using the standard DASD I/O system, and the internal dbspaces are mapped. Because the internal dbspaces are included in storage pool 1, any activity recorded for them will be included with the totals for pool number 1.

+--------------------------------------------------------------------------------+
|counter pool *                                                                  |
|Counter values at  DATE='05-24-91'  TIME='10:13:49'                             |
|                                                                                |
|Directory:  Data Spaces                                                         |
|Pages looked at in the buffer  LBUFLOOK:  90                                    |
|Pages moved from DS to buffer  DSREAD  :  57                                    |
|Pages moved from buffer to DS  DSWRITE :  28                                    |
|DS page fault notifications    DSFAULT :  5                                     |
|                                                                                |
|Pool No. 1:  Data Spaces                                                        |
|Pages looked at in the buffer  LBUFLOOK:  1005                                  |
|Pages moved from DS to buffer  DSREAD  :  77                                    |
|Pages moved from buffer to DS  DSWRITE :  0                                     |
|DS page fault notifications    DSFAULT :  18                                    |
|                                                                                |
|Pool No. 2:  *BLOCKIO                                                           |
|Pages looked at in the buffer  LBUFLOOK:  237                                   |
|Page reads                     PGREAD  :  42                                    |
|Page writes                    PGWRITE :  12                                    |
|IUCV *BLOCKIO I/O requests     IUCVBIO :  9                                     |
|                                                                                |
|Total count for storage pools using data spaces:                                |
|Pages looked at in the buffer  LBUFLOOK:  1005                                  |
|Pages moved from DS to buffer  DSREAD  :  77                                    |
|Pages moved from buffer to DS  DSWRITE :  0                                     |
|DS page fault notifications    DSFAULT :  18                                    |
|                                                                                |
|Total count for storage pools using *BLOCKIO:                                   |
|Pages looked at in the buffer  LBUFLOOK:  237                                   |
|Page reads                     PGREAD  :  42                                    |
|Page writes                    PGWRITE :  12                                    |
|IUCV *BLOCKIO I/O requests     IUCVBIO :  9                                     |
|ARI0065I Operator command processing is complete.                               |
+--------------------------------------------------------------------------------+

This example shows a database where the directory is using the standard DASD I/O system.

+--------------------------------------------------------------------------------+
|counter pool dir                                                                |
|Counter values at  DATE='05-23-91'  TIME='15:41:07'                             |
|                                                                                |
|Directory:  *BLOCKIO                                                            |
|Pages looked at in the buffer  LBUFLOOK:  410                                   |
|Page reads                     PGREAD  :  52                                    |
|Page writes                    PGWRITE :  11                                    |
|IUCV *BLOCKIO I/O requests     IUCVBIO :  9                                     |
|ARI0065I Operator command processing is complete.                               |
+--------------------------------------------------------------------------------+

This example shows a database using unmapped internal dbspaces. Any activity recorded for these dbspaces will only appear under the heading Unmapped Internal Dbspaces. It will not be included in the totals for the storage pool that contains the internal dbspaces.

+--------------------------------------------------------------------------------+
|counter pool unmapped                                                           |
|Counter values at  DATE='07-29-91'  TIME='17:12:37'                             |
|                                                                                |
|Unmapped Internal Dbspaces:  Data Spaces                                        |
|Pages looked at in the buffer  LBUFLOOK:  515                                   |
|Pages moved from DS to buffer  DSREAD  :  21                                    |
|Pages moved from buffer to DS  DSWRITE :  2                                     |
|DS page fault notifications    DSFAULT :  0                                     |
|ARI0065I Operator command processing is complete.                               |
+--------------------------------------------------------------------------------+