Thread Group Buffer Pool Activity

This panel provides a summary of group buffer pool usage for an individual thread.

This panel is only available in a data sharing environment.


________________ ZTGBUF   VTM     O2       V550.#P SN12 11/04/13 17:31:07   2   
> Help PF1                                                            Back PF3  
                                                                                
>       THREAD INFORMATION:  Enter a selection letter on the top line.          
                                                                                
> A-THREAD DETAIL B-LOCK COUNTS C-LOCK WAITS     D-LOCKS OWNED  E-GLOBAL LOCKS  
> F-CURRENT SQL   G-SQL COUNTS  H-DISTRIBUTED    I-BUFFER POOL  *-GROUP BP      
> K-PACKAGES      L-RES LIMIT   M-PARALLEL TASKS N-UTILITY      O-OBJECTS       
> P-CANCEL THREAD Q-DB2 CONSOLE R-DSN ACTIVITY   S-APPL TRACE   T-ENCLAVE       
> U-LONG NAMES                  W-ACCEL ACTIVITY                                
=============================================================================== 
>                    THREAD GROUP BUFFER POOL ACTIVITY                          
 PLAN                                                                           
+ Thread:  Plan=DSNREXX   Connid=DB2CALL  Corrid=MIS310       Authid=MIS        
+ Attach:  BATCH          JOB Name=MIS310                     JOB Asid= 249     
+ Package: DPTDEL                         Collection=DMSYSWLD                   
+ Luwid=DEIBMIPS.IPSATN12.CC36CB8E09FE=6071                                     
 gbuf                                                                           
+ Group Buffer Pool:   ALL                                                      
+ Reads - Cross-Invalidation:             Reads - Page Not Found:               
+   Data Returned             =       0     Data Returned             =       1 
+   Data not in GBP-R/W Int   =       0     Data not in GBP-R/W Int   =       1 
+   Data not in GBP-No R/W Int=       0     Data not in GBP-No R/W Int=       6 
+ Read Hit Percentage         =   12.5%   Read-to-Write Percentage    =   26.6% 
+ Changed Pages Written       =      22   Clean Pages Written         =       0 
+                                                                               
+ Group Buffer Pool:   GBP0                                                     
+ Reads - Cross-Invalidation:             Reads - Page Not Found:               
+   Data Returned             =       0     Data Returned             =       0 
+   Data not in GBP-R/W Int   =       0     Data not in GBP-R/W Int   =       0 
+   Data not in GBP-No R/W Int=       0     Data not in GBP-No R/W Int=       0 
+ Read Hit Percentage         =     .0%   Read-to-Write Percentage    =     .0% 
+ Changed Pages Written       =       1   Clean Pages Written         =       0 
+                                                                               
+ Group Buffer Pool:   GBP3                                                     
+ Reads - Cross-Invalidation:             Reads - Page Not Found:               
+   Data Returned             =       0     Data Returned             =       1 
+   Data not in GBP-R/W Int   =       0     Data not in GBP-R/W Int   =       1 
+   Data not in GBP-No R/W Int=       0     Data not in GBP-No R/W Int=       6 
+ Read Hit Percentage         =   12.5%   Read-to-Write Percentage    =   27.5% 
+ Changed Pages Written       =      21   Clean Pages Written         =       0 
===============================================================================

Highlighting

The following table shows the field that might be highlighted in the panel above to indicate that an exception that is related to this field exceeded its threshold value:

Table 1. Highlighted fields in Thread Group Buffer Pool Activity panel.

This table shows the field and the exception this field is related to. It also shows the reason for the exception.
Field Exception Reason
Plan Any Same as other thread detail panels.

Navigation

For additional information about
  • related topics, select one of the options on the top of the panel.
  • other topics, use the PF keys.

Fields

Thread identifier: This information identifies the thread to which the information in this panel applies.
Plan
The Db2 plan name of the active thread.
Connid
The Db2 connection identifier of the active thread.
Corrid
The Db2 correlation identifier of the active thread. If the correlation is not set, N/A is displayed.
Authid
The Db2 authorization identifier of the active thread.
Attach
Depending on the type of connection, the appropriate information is displayed.
Attach information is displayed only if the thread is a distributed allied thread (not for distributed database access threads).
Connection Type
Batch
The MVS jobname and ASID.
Note: For threads from remote Db2, the MVS job name is N/A.
CICS®
The CICS jobname, task name, task number, terminal ID, and thread type. The thread type is:
Pool
The thread in use is a pool thread.
Entry
The thread in use is a nonprotected entry thread.
Prot
The thread in use is a protected thread. Protected threads are defined in an RCT entry definition using the THRDS operand.
IMS
The IMS region number, transaction name, region name, and terminal ID (LTERM).
RRSAF
The MVS job name and ASID.
Note: For threads from remote Db2, the MVS job name is N/A.
System
The originating Db2 job name and the resource manager that is the source of the thread. An additional line below the Attach line identifies the user thread, if any, being served by the system thread.
TSO
The TSO user ID and region ASID.
Utility
No additional information.
Db2
The Db2 subsystem identifier.
MVS
The MVS system identifier.
ORIGAUTH
The original (primary) Db2 authorization identifier of the thread. This field displays only when the original identifier is different from the Authid.
Package identifier: This information identifies the package to which the information in this panel applies.
Package
The Db2 package name of the active thread. Up to 18 characters of the package name are returned.
Collection
The package collection identifier. This field is displayed only if a package is being used.
Distributed thread identifier: The following fields are displayed if the thread has a distributed relationship with a remote Db2 subsystem.
Type
The distributed thread type.
Distributed Allied
A requesting thread; one that has issued an SQL call to a remote Db2 location.
Database Access
A responding thread; one that is serving a remote Db2 location by responding to an SQL call.
Db2=
The Db2 subsystem ID, indicating the member of the data sharing group of this thread.
Luwid
This value consists of two parts: the logical unit of work ID (luw-id) and a token. The token can be used in place of the luw-id in any Db2 command that accepts luw-id as input. Format:
luw-id=token

The luw-id consists of the network name, the originating VTAM® LUNAME, and a unique identifier (separated by periods). Thus, the Luwid field displays data like in the following example:

USCACO01.O2D22A.A1FE8E04B9D4=8
System
The originating Db2 job name and the resource manager that is the source of the thread. An additional line below the Attach line identifies the user thread, if any, being served by the system thread.

Group buffer pool information:

Group Buffer Pool
The group buffer pool ID.
Reads - Cross-Invalidation: Data Returned
The number of reads to the group buffer pool required because the page in the member's buffer pool was invalidated, where the data was found and returned to the member.
Reads - Page Not Found: Data Returned
The number of reads to the group buffer pool required because the page was not in the member's buffer pool, where the data was found and returned to the member.
Reads - Cross-Invalidation: Data not in GBP-R/W Int
The number of reads to the group buffer pool required because the page in the member's buffer pool was invalidated, where
  • the data was not found in the group buffer pool and the member had to go to DASD to read the page, and
  • other members had read/write interest in the pageset, so Db2 created a directory entry for this page if it did not already exist.
Reads - Page Not Found: Data not in GBP-R/W Int
The number of reads to the group buffer pool required because the page was not in the member's buffer pool, where
  • the data was not found in the group buffer pool and the member had to go to DASD to read the page, and
  • other members had read/write interest in the pageset, so Db2 created a directory entry for this page if it did not already exist.
Reads - Cross-Invalidation: Data not in GBP-No R/W Int
The number of reads to the group buffer pool required because the page in the member's buffer pool was invalidated, where
  • the data was not found in the group buffer pool and the member had to go to DASD to read the page, and
  • no other member had read/write interest in the pageset, so Db2 did not have to register the page, since another member cannot cause a cross-invalidation by updating a page.
Reads - Page Not Found: Data not in GBP-No R/W Int
The number of reads to the group buffer pool required because the page was not in the member's buffer pool, where
  • the data was not found in the group buffer pool and the member had to go to DASD to read the page, and
  • no other member had read/write interest in the pageset, so Db2 did not have to register the page, since another member cannot cause a cross-invalidation by updating a page.
Read Hit Percentage
The percentage of all Reads to the group buffer pool for which the needed data was found and returned to the member.
Read-to-Write Percentage
The ratio of reads to writes expressed as a percentage for the group buffer pool.
Changed Pages Written
The number of changed pages written to the group buffer pool. Pages can be forced out before the application commits if a buffer pool threshold is reached, or when P-lock negotiation forces the pages on the vertical Deferred Write queue to be written to the group buffer pool.
Clean Pages Written
The number of clean pages written to the group buffer pool. Db2 writes clean pages for pagesets and partitions defined with GBPCACHE ALL.