DSNB401I   BUFFERPOOL NAME bp-name, BUFFERPOOL ID bp-id, USE COUNT use-count

Explanation

This message displays output from the DISPLAY BUFFERPOOL command. For each buffer pool, this message marks the beginning of multiple lines of information about that buffer pool. Some lines in the output have their own message numbers or alphanumeric identifiers to assist with identification.

The first line (DSNB401I) contains the following information:

bp-name
The external name of the buffer pool. bp-name can be one of the following values: BP0, BP1 - BP49, BP8KB, BP16KB, BP32K, BP32K1 - BP32K9.
bp-id
The internal identifier for the buffer pool. bp-id can be one of the following values: 0 - 49, 80 - 89.
use-count
The number of open table spaces or index spaces that use this buffer pool. A value of zero means that the buffer pool is inactive.

The remaining output for each buffer pool consists of one or more of the following sections, in the indicated order:

If information cannot be reported, one or more of the following messages is returned:

The DISPLAY BUFFERPOOL output ends with one of the following messages:

DSNB402I: Information about allocation status

The basic buffer pool information is followed by a description of the allocation status of the buffer pool. 

DSNB402I - BUFFER POOL SIZE = pool-size BUFFERS  AUTOSIZE = autosize
             ALLOCATED      = allocated-buffers   TO BE DELETED   = delete-buffers
             IN-USE/UPDATED = current-buffers
BUFFER POOL SIZE = pool-size BUFFERS
The user-specified buffer pool size.
AUTOSIZE = autosize
The buffer pool AUTOSIZE attribute that is applicable to the current allocation of the buffer pool.
YES
The buffer pool uses Workload Manager (WLM) services, if available, to automatically adjust the size of the buffer pool. The size is adjusted based on dynamic monitoring of the workload goals and the storage that is available on the system.
NO
The buffer pool does not use WLM services for automatic sizing adjustment of buffer pools.
ALLOCATED = allocated-buffers
The number of allocated buffers in an active buffer pool.
TO BE DELETED = delete-buffers
The number of buffers to be deleted in an active buffer pool because of pool contraction.
IN-USE/UPDATED = current-buffers
The number of currently active buffers in the buffer pool. These buffers cannot be stolen.

DSNB404I: Threshold information

The information about allocation status is followed by information about the user-modifiable thresholds for the buffer pool.

DSNB404I - THRESHOLDS -
             VP SEQUENTIAL             = vpseq
             DEFERRED WRITE            = dwt
             VERTICAL DEFERRED WRT     = dwv1,dwv2
             PARALLEL SEQUENTIAL       = vppseqt
             ASSISTING PARALLEL SEQT   = vpxpseqt
vpseq
The sequential steal threshold for the virtual pool, expressed as a percentage of the total buffer pool size.
spseq
The sequential steal threshold for the simulated pool, expressed as a percentage of the total simulated buffer pool size.
dwt
The free-buffer deferred write threshold for the buffer pool, expressed as a percentage of the total buffer pool size.
dwv1
The vertical deferred write threshold for the buffer pool, expressed as a percentage of the total buffer pool size.
dwv2
The vertical deferred write threshold for the buffer pool, expressed as an absolute number of buffers. dwv2 is used to determine the threshold only if dwv1 is 0 and dwv2 is non-zero. Otherwise, dwv1 is used to determine the threshold.
vppseqt
The sequential threshold for parallel query processing, expressed as a percentage of the virtual sequential steal threshold. When the threshold is set to 0, parallel query processing is not supported.
vpxpseqt
The assisting parallel sequential threshold, expressed as a percentage of the sequential threshold for parallel query processing. Use the vpxpseqt value to control how much buffer resource is used when this DB2® member is assisting another member of the group in parallel processing. When the threshold is set to 0, this buffer pool is not used to assist other data-sharing members in processing a query. In a non-data- sharing environment, this value is ignored.

DSNB406I: PGFIX and PGSTEAL information

The DISPLAY BUFFERPOOL output includes a description of the PGFIX and PGSTEAL attributes for the buffer pool.

DSNB406I -   PGFIX ATTRIBUTE -
             CURRENT                   = current-pgfix
             PENDING                   = pending-pgfix
             PAGE STEALING METHOD      = current-pgsteal
CURRENT = current-pgfix
The value of the page fix (PGFIX) attribute for the current allocation of the buffer pool.
YES
The buffer pool is fixed in real storage for the long term.
NO
The buffer pool is fixed in real storage only during an I/O operation.
PENDING = pending-pgfix
The value of the PGFIX attribute that is to be applied for the next allocation of the virtual buffer pool.
YES
The buffer pool is to be fixed in real storage for the long term.
NO
The buffer pool is to be fixed in real storage only during an I/O operation.
PAGE STEALING METHOD = current-pgsteal
The page stealing method (PGSTEAL) that is in use for the buffer pool.
LRU
The least recently used (LRU) algorithm is used to manage page stealing. This method is the default value.
FIFO
The first-in, first-out (FIFO) algorithm is used to manage page stealing.
NONE
No page stealing occurs. Objects that use this buffer pool are kept resident.
Related information:

DSNB408I: No detail statistics available

DSNB408I indicates that, although you specified the DETAIL option on the DISPLAY BUFFERPOOL command, no detail statistics are available for the requested buffer pool. The statistics are not available because the pool has not been activated since DB2 started.

DSNB408I NO DETAIL STATISTICS AVAILABLE FOR BUFFER POOL bp-name
BUFFER POOL bp-name
The name of the buffer pool.

DSNB409I: Start time of the statistics interval for DETAIL(INTERVAL)

When you specify the DETAIL(INTERVAL) option, the output includes the start time of the interval for which the statistics were accumulated. 

DSNB409I - INCREMENTAL STATISTICS SINCE base-time
base-time
The start time. This value is either the time of the previous incremental display or, if no previous incremental display exists, the time that the buffer pool was first activated.

The format is hh:mm:ss month dd, yyyy

hh:mm:ss
The time expressed as hour:minutes:seconds.
month
An alphanumeric abbreviation for the month. For example, a value of OCT means October.
dd
The day of the month.
yyyy
The year.

DSNB410I: Start time of the statistics interval for DETAIL(*)

When you specify the DETAIL(*) option, the output includes the start time of the interval for which the statistics were accumulated. 

DSNB410I - CUMULATIVE STATISTICS SINCE base-time
base-time
The start time. This value is the time the buffer pool was first activated.

The format is hh:mm:ss month dd, yyyy

hh:mm:ss
The time expressed as hour:minutes:seconds.
month
An alphanumeric abbreviation for the month. For example, a value of OCT means October.
dd
The day of the month.
yyyy
The year.

DSNB411I: Page read statistics

When you specify the DETAIL option, the output includes the page read statistics for the buffer pool. 

DSNB411I - RANDOM GETPAGE    = rgp
           SYNC READ I/O (R) = srr
           SEQ.   GETPAGE    = sgp
           SYNC READ I/O (S) = srs
           DMTH HIT          = dmt
           PAGE-INS REQ      = pir
           SEQUENTIAL        = seq
           VPSEQT HIT        = vsh
           RECLASSIFY        = rcy
RANDOM GETPAGE = rgp
The number of nonsequential GETPAGE requests.
SYNC READ I/O (R) = srr
The number of synchronous read I/O operations for nonsequential GETPAGE requests.
SEQ. GETPAGE = sgp
The number of sequential GETPAGE requests.
SYNC READ I/O (S) = srs
The number of synchronous read I/O operations for sequential GETPAGE requests.
DMTH HIT = dmt
The number of times that the data management threshold was reached.
PAGE-INS REQ = pir
The number of page-in operations that are required for read I/O.
SEQUENTIAL = seq
The number of buffers on the sequential least-recently-used (SLRU) chain.
VPSEQT HIT = vsh
The number of times that the size of the SLRU chain reached the sequential steal threshold (the VPSEQT value) for the buffer pool.
RECLASSIFY = rcy
A statistic that is used by IBM® for serviceability.
Related information:

DSNB412I: Sequential prefetch statistics

When you specify the DETAIL option, the output includes the sequential prefetch statistics for the buffer pool.

DSNB412I - SEQUENTIAL PREFETCH -
             REQUESTS        =        pft   PREFETCH  I/O   =        pio
             PAGES READ      =        pfp
REQUESTS = pft
The number of times that sequential prefetch was requested.
PREFETCH I/O = pio
The number of sequential prefetch read I/O operations.
PAGES READ = pfp
The number of pages that are read because of sequential prefetch.
Related information:

DSNB413I: List prefetch statistics

When you specify the DETAIL option, the output includes the list prefetch statistics for the buffer pool.

DSNB413I - LIST PREFETCH -
             REQUESTS        =        pft   PREFETCH  I/O   =        pio
             PAGES READ      =        pfp
REQUESTS = pft
The number of times that list prefetch was requested.
PREFETCH I/O = pio
The number of list prefetch read I/O operations.
PAGES READ = pfp
The number of pages that are read because of list prefetch.
Related information:

DSNB414I: Dynamic prefetch statistics

When you specify the DETAIL option, the output includes the dynamic prefetch statistics for the buffer pool.

DSNB414I - DYNAMIC PREFETCH -
             REQUESTS        =        pft   PREFETCH  I/O   =        pio
             PAGES READ      =        pfp
REQUESTS = pft
The number of times that dynamic prefetch was requested.
PREFETCH I/O = pio
The number of dynamic prefetch read I/O operations.
PAGES READ = pfp
The number of pages that are read because of dynamic prefetch.
Related information:

DSNB415I: Prefetch statistics

When you specify the DETAIL option, the output includes the prefetch statistics for the buffer pool.

DSNB415I - PREFETCH DISABLED -
             NO BUFFER       =        pfd   NO READ ENGINE  =           ree
NO BUFFER = pfd
The number of times that prefetch was disabled for one of the following reasons:
  • The buffer pool reached the prefetch disabled threshold (90% full).
  • A user disabled prefetch by setting the VPSEQT threshold for the buffer pool to zero.
NO READ ENGINE = ree
The number of times that prefetch was disabled because an asynchronous read processor was not available.
Related information:

DSNB420I: Page write statistics

When you specify the DETAIL option, the output includes the page write statistics for the buffer pool. 

DSNB420I - SYS PAGE UPDATES  =        pages-updated SYS PAGES WRITTEN =           pages-written
           ASYNC WRITE I/O   =        async-writes  SYNC WRITE I/O    =           sync-writes
           PAGE-INS REQ      =        page-ins
SYS PAGE UPDATES = pages-updated
The number of buffer updates.
SYS PAGES WRITTEN = pages-written
The number of pages that are written to disk.
ASYNC WRITE I/O = async-writes
The number of asynchronous write I/O operations.
SYNC WRITE I/O = sync-writes
The number of synchronous write I/O operations.
PAGE-INS REQ = page-ins
The number of page-ins that are required for write I/O.

DSNB421I: Page-write threshold statistics

When you specify the DETAIL option, the output includes the page-write threshold statistics for the buffer pool.

DSNB421I - DWT HIT           =        dwt VERTICAL DWT HIT  =           vdw
DWT HIT = dwt
The number of times that the deferred write threshold was reached.
VERTICAL DWT HIT = vdw
The number of times that the vertical deferred write threshold was reached.
Related information:

DSNB440I: Parallel activity statistics

When you specify the DETAIL option, the output includes statistics about parallel activities for the buffer pool.

DSNB440I - PARALLEL ACTIVITY -
           PARALLEL REQUEST  =        tpa   DEGRADED PARALLEL =       dpa
PARALLEL REQUEST = tpa
The total number of negotiations with the buffer pool for the requested number of sequential prefetch streams.
DEGRADED PARALLEL = dpa
The total number of times that the negotiation resulted in the degraded mode of parallel operations.

DSNB441I: LPL activity statistics

When you specify the DETAIL option, the output includes statistics about LPL activity for the buffer pool.

DSNB441I - LPL ACTIVITY -
           PAGES ADDED       =        pages
pages
The total number of pages for all page sets that are added to the logical page list (LPL) in this buffer pool. This value is equal to the number of DSNB250E messages that are written to the system log after the most recent execution of the DISPLAY BUFFERPOOL command with the DETAIL option.
Related information:

DSNB453I: Cached and changed page statistics

The output includes the number of cached pages and changed pages in the buffer pool for a data set if all of the following conditions are true:

  • You specified the LSTATS option on the DISPLAY BUFFERPOOL command.
  • The buffer pool is an active buffer pool.
  • The number of cached and changed pages are not zero.

The relevant table space or index space is identified in either line DSNB464I or line DSNB465I. The data set is identified in line DSNB466I.

DSNB453I - VP CACHED PAGES -
           CURRENT       =        vcount   MAX           =        mvcount
           CHANGED       =        ccount   MAX           =        mccount
CURRENT = vcount
The number of cached pages in the virtual pool for the data set. This value is the number of buffers that contain pages for the data set in the buffer pool.
MAX = mvcount
The maximum number of cached pages in the virtual pool for the data set since the last DISPLAY BUFFERPOOL command with the LSTATS option was issued.
CHANGED = ccount
The number of changed pages in the virtual pool for the data set. This value is the number of buffers that were changed in the buffer pool for the data set.
MAX = mccount
The maximum number of changed pages in the virtual pool for the data set since the last DISPLAY BUFFERPOOL command with the LSTATS option was issued.

DSNB455I: Synchronous I/O delay statistics

The output includes synchronous I/O delay statistics if all of the following conditions are true:

  • You specified the LSTATS option on the DISPLAY BUFFERPOOL command.
  • The buffer pool is an active buffer pool.
  • The values of the synchronous I/O delay statistics are not zero.

These synchronous I/O delay statistics are reported for a data set for an open table space or index space that is associated with the buffer pool. The values that are listed are the statistics that were gathered since the last display for the data set.

The relevant table space or index space is identified in either line DSNB464I or line DSNB465I. The relative data set within the table space or index space is identified in line DSNB466I.

DSNB455I - SYNCHRONOUS I/O DELAYS -
             AVERAGE DELAY         = avd
             MAXIMUM DELAY         = mxd
             TOTAL PAGES           = tpg
avd
The average I/O delay in milliseconds for pages in the data set.
mxd
The maximum I/O delay in milliseconds for pages in the data set.
tpg
The total number of pages that are read or written for the data set.
Related information:

DSNB456I: Asynchronous I/O delay statistics

The output includes asynchronous I/O delay statistics if all of the following conditions are true:

  • You specified the LSTATS option on the DISPLAY BUFFERPOOL command.
  • The buffer pool is an active buffer pool.
  • The values of the asynchronous I/O delay statistics are not zero.

These asynchronous I/O delay statistics are reported for a data set for an open table space or index space that is associated with the buffer pool. The values that are listed are the statistics that were gathered since the last display for the data set.

The relevant table space or index space is identified in either line DSNB464I or line DSNB465I. The relative data set within the table space or index space is identified in line DSNB466I.

DSNB456I - ASYNCHRONOUS I/O DELAYS -
             AVERAGE DELAY         = avd
             MAXIMUM DELAY         = mxd
             TOTAL PAGES           = tpg
             TOTAL I/O COUNT       = tio
avd
The average I/O delay in milliseconds for pages in the data set.
mxd
The maximum I/O delay in milliseconds for pages in the data set.
tpg
The total number of pages that are read or written for the data set.
tpg
The total number of I/O operations that are issued for the data set.

DSNB459I: Open failure for a data set

Message DSNB459I indicates that a previous attempt to access a data set failed because of an allocation or open error. This message is displayed only when you specify the LIST option on the DISPLAY BUFFERPOOL command for an active buffer pool and this error condition occurs.

The relevant table space or index space is identified in either line DSNB464I or line DSNB465I. 

DSNB459I - csect-name OPEN FAILURE HAS OCCURRED FOR DATASET dsn
csect-name
The name of the control section that issued the message.
DATASET = dsn
The data set number. This value is the relative data set number within a table space or index space.

Other data set and buffer pool information might be displayed in subsequent messages.

DSNB460I: Page set and partition list information (for a data-sharing environment)

When you specify the LIST option, the output includes information about page sets and partition lists.

The message output begins with the introductory text PAGE SET/PARTITION LIST INFORMATION. The introductory text is followed by column headers and multiple lines of information.

DSNB460I  @
----------------PAGE SET/PARTITION LIST INFORMATION----------------
                                  --------DATA SHARING INFO--------
                               TS GBP  MEMBER  CASTOUT  USE  P-LOCK
DATABASE SPACE NAME  INST PART IX DEP   NAME    OWNER  COUNT STATE 
======== =========== ==== ==== == === ======== ======= ===== ======
DATABASE
The name of the database. This field is blank when the line provides information about the same database as the preceding line or lines.
SPACE NAME
The name of the table space. This field is blank when the line provides information about the same table space as the preceding line or lines.
INST
The instance number.
PART
One of the following values:
  • The partition number.
  • For a simple table space or simple index space: a blank.
  • For non-partitioned indexes on a partitioned table space: the logical partition number preceded by the character L (for example, L01).
TS IX
The type of object: either TS for table space or IX for index space.
GBP DEP
An indicator of group buffer pool (GBP) dependency. The indicator can be either of the following values:
Y
The page set or partition is GBP-dependent.
N
The page set or partition is not GBP-dependent.
MEMBER NAME
The name of the member that the detail line pertains to.
CASTOUT OWNER
An indicator of whether the member is the castout owner. The indicator can be either of the following values:
Y
The member is the castout owner.
Blank
The member is not the castout owner.
USE COUNT
The number of active claimers or drainers for the page set or partition for the member.
P-LOCK STATE
The P-lock state that the member currently holds. The state can be any of the following values:
IS
R/O interest. Other members have interest in this page set or partition. The page set or partition is GBP-dependent.
IX
R/W interest. Other members have interest in this page set or partition. The page set or partition is GBP-dependent.
S
R/O interest. Other members might be reading the page set or partition. The page set or partition is not GBP-dependent.
SIX
R/W interest. Other members might be reading the page set or partition. The page set or partition is GBP-dependent.
NSU
R/W interest. The page set or partition is GBP-dependent.
X
R/W interest. No other members are accessing the page set or partition. The page set or partition is not GBP-dependent.
US
A temporary state that can be held by a restarting DB2 when "waiting for retained locks" is enabled.
number
A number for use as a diagnostic aid. A number is displayed only when a DISPLAY BUFFERPOOL command encounters an undefined lock state.

If the DISPLAY BUFFERPOOL LIST command finds more than 255 lines of output to display, the output is presented in multiple sections. Each section is a new instance of message DSNB460I with the addition of "(CONTINUED)" in the message heading:

DSNB460I  @ (CONTINUED)

Message DSNB460I is issued in a data-sharing environment. In a non-data-sharing environment, message DSNB464I is issued instead.

If no information is available, message DSNB460I is followed by message DSNB463I.

DSNB463I: No objects matched selection criteria

Message DSNB463I indicates that DB2 did not find any page sets or partitions that matched the selection criteria.

DSNB463I - * * * NO OBJECTS MATCHED LIST/LSTATS SELECTION CRITERIA

For example, this message is displayed for DIS BPOOL(BP0) GBPDEP(Y) if DB2 did not find any page sets or partitions that are group-buffer-pool dependent (GBP-dependent).

When message DSNB463I is returned, the DISPLAY BUFFERPOOL command terminates normally.

If you expected to see a list of page sets or partitions, review and correct the syntax of the DISPLAY BUFFERPOOL command as needed. Consider adding or changing the filter keywords to obtain a list of page sets or partitions.

DSNB464I: Page set and partition list information (for a non-data-sharing environment)

When you specify the LIST option, the output includes information about page sets and partition lists.

The message output begins with the introductory text PAGE SET/PARTITION LIST INFORMATION. The introductory text is followed by column headers and multiple lines of information. 

DSNB464I  @
PAGE SET/PARTITION LIST INFORMATION
                               TS  USE  
DATABASE SPACE NAME  INST PART IX COUNT 
======== =========== ==== ==== == =====
DATABASE
The name of the database. This field is blank when the line provides information about the same database as the preceding line or lines.
SPACE NAME
The name of the table space. This field is blank when the line provides information about the same table space as the preceding line or lines.
INST
The instance number.
PART
One of the following values:
  • The partition number.
  • For a simple table space or simple index space, a blank.
  • For non-partitioned indexes on a partitioned table space, the logical partition number preceded by the character L (for example, L01).
TS IX
The type of object: either TS for table space or IX for index space.
USE COUNT
The number of active claimers or drainers for the page set or partition for the member.

If the DISPLAY BUFFERPOOL LIST command finds more than 255 lines of output to display, the output is presented in multiple sections. Each section is a new instance of message DSNB464I with the addition of "(CONTINUED)" in the message heading:

DSNB464I  @ (CONTINUED)

Message DSNB464I is issued in a non-data-sharing environment. In a data-sharing environment, message DSNB460I is issued instead.

If no information is available, message DSNB464I is followed by message DSNB463I.

DSNB466I: Page set and partition statistics

When you specify the LSTATS option, the output includes statistics for data sets. Those statistics are introduced by message DSNB466I.

DSNB466I -
------------------PAGE SET/PARTITION STATISTICS-------------------

DSNB467I: Data set statistics

When you specify the LSTATS option, the output includes statistics about data sets for objects that are associated with active buffer pools.

DSNB467I - STATISTICS FOR object-type database-name.space-name INSTANCE instance-number - 
DATA SET #: set-number USE COUNT: application-count
STATISTICS FOR object-type
The type of object: either TABLE SPACE or INDEX SPACE.
database-name
The name of the database.
space-name
The name of the table space or index space.
instance-number
The instance number of the table space or index space.
DATA SET #: set-number
The relative data set number within the table space or index space.
USE COUNT: application-count
The number of applications that have a claim or drain on the page set or partition.

This message is followed by one or more of the following messages: DSNB453I, DSNB455I, or DSNB456I.

Related information:

DSN9022I: Normal completion

The DISPLAY THREAD output normally ends with message DSN9022I. 

DSN9022I - DSNB1CMD '-DISPLAY BUFFERPOOL' NORMAL COMPLETION
Related information:

DSNB499I: Display terminated because of insufficient space

If the DISPLAY BUFFERPOOL output is too long, the output ends with message DSNB499I. This message indicates that the command was unable to obtain storage for more messages. This situation occurs only for a long display request, such as a detail display for many buffer pools.

DSNB499I - DISPLAY TERMINATED DUE TO INSUFFICIENT MESSAGE SPACE

The output is truncated.

Reissue the DISPLAY BUFFERPOOL command, and specify a smaller number of buffer pools.

System action

Processing continues.