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

The DSNB401I message displays output from the -DISPLAY BUFFERPOOL command (Db2). 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 of the output contains the following information.

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

bp-name

The external name of the buffer pool. bp-name can be one of the following values: BP0 to BP49, BP8K0 to BP8K9, BP16K0 to BP16K9, BP32K, or BP32K1 to BP32K9.

bp-id

The internal identifier for the buffer pool. bp-id can be one of the following values: 0 to 49, 80 to 89, 100 to 109, or 120 to 129.

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.

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

The values of VPSIZE MINIMUM and VPSIZE MAXIMUM are used only when AUTOSIZE =YES.

DSNB402I - BUFFER POOL SIZE = pool-size BUFFERS  AUTOSIZE = autosize
           VPSIZE MINIMUM = minimum size VPSIZE MAXIMUM = maximum-size
             ALLOCATED      = allocated-buffers   TO BE DELETED   = delete-buffers
             IN-USE/UPDATED = current-buffers
             OVERFLOW ALLOC = over-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.

VPSIZE MINIMUM = minimum size

The minimum size of the buffer pool. This value is meaningful only when the value of autosize is YES. If the value was never specified, a value of 0 is shown, and Db2 uses a default value of 75% of the specified value of VPSIZE.

VPSIZE MAXIMUM = maximum-size

The maximum size of the buffer pool. This value is meaningful only when the value of autosize is YES. If the value was never specified, a value of 0 is shown, and Db2 uses the defaults value, which is 25% greater than the specified VPSIZE value.

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.

OVERFLOW ALLOC = over-buffers

The number of allocated buffers in the overflow area for a buffer pool that uses PGSTEAL(NONE). The buffers that are allocated to the overflow area are counted within of the VPSIZE value, and they are counted as part of the ALLOCATED value.

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

DSNB404I - THRESHOLDS -
             VP SEQUENTIAL             = vpseq
             SP SEQUENTIAL             = spseq
             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.

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                   = current-pgsteal
             PENDING                   = pending-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 = current-pgsteal

The value of the page stealing method 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.

PENDING = pending-pgsteal

The value of the page stealing method (PGSTEAL) that is to be applied for the next allocation of the virtual 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

• Fixing a buffer pool in real storage
• Choosing a page-stealing algorithm

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                   = current-pgsteal
             PENDING                   = pending-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 = current-pgsteal

The value of the page stealing method 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.

PENDING = pending-pgsteal

The value of the page stealing method (PGSTEAL) that is to be applied for the next allocation of the virtual 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

• Fixing a buffer pool in real storage
• Choosing a page-stealing algorithm

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.

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.

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.

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
           SYNC READ I/O (ZHL) = srrz
           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.

SYNC READ I/O (ZHL) = srrz

The number of synchronous read I/O operations using zHyperLink.

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

• Buffer pool thresholds that you can change
• -ALTER BUFFERPOOL command (Db2)

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

• Sequential prefetch (PREFETCH='S')

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

• List prefetch (PREFETCH='L' or 'U')

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

• Dynamic prefetch (PREFETCH='D')

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

• Read operations and prefetch I/O

When you specify the DETAIL option, the output includes the page read statistics for the overflow area.

DSNB416I - OVERFLOW RANDOM GETPAGE    = argp
           OVERFLOW SYNC READ I/O (R) = asrr
           OVERFLOW SEQ.   GETPAGE    = asgp
           OVERFLOW SYNC READ I/O (S) = asrs

OVERFLOW RANDOM GETPAGE = argp

The number of nonsequential getpage requests that use overflowed buffers.

VERFLOW SYNC READ I/O (R) = asrr

The number of synchronous read I/O operations for nonsequential getpage requests that use overflowed buffers.

OVERFLOW SEQ. GETPAGE =asgp

The number of sequential getpage requests that use overflowed buffers.

OVERFLOW SYNC READ I/O (S) = asrs

The number of synchronous read I/O operations for sequential getpage requests that use overflowed buffers.

Related information

• Choosing a page-stealing algorithm

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.

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

• Buffer pool thresholds that you can change

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

DSNB431I - SIMULATED BUFFER POOL SIZE = pool-size BUFFERS
             ALLOCATED       = allocated-buffers
             IN-USE          = current-in-use   HIGH-IN-USE = high-in-use
             SEQ-IN-USE      = current-sequential-in-use HIGH SEQ-IN-USE = high-sequential-in-use

SIMULATED BUFFER POOL SIZE = pool-size BUFFERS

The user-specified simulated buffer pool size.

ALLOCATED = allocated-buffers

The number of simulated buffers that are currently allocated in the simulated buffer pool.

IN-USE = current-in-use

The number of simulated buffers that are currently being used to track pages.

HIGH IN-USE = high-in-use

The highest number of simulated buffers that have been in use in the simulated buffer pool since the buffer pool simulation began.

SEQ IN-USE = current-sequential-in-use

The number of simulated buffers for sequentially accessed pages that are currently in use in the simulated buffer pool.

HIGH SEQ-IN-USE = high-sequential-in-use

The highest number of simulated buffers for sequentially accessed pages that have been in use in the simulated buffer pool since the buffer pool simulation began.

When you specify the DETAIL option, the output includes statistics on activity in the simulated buffer pool, including the numbers of page accesses that the buffer pool simulation determined could be avoided, for various types of read activity.

DSNB432I - SIMULATED BUFFER POOL ACTIVITY -
             AVOIDABLE READ PAGE MISSES - 
               SYNC    FROM DASD (R) = pages-sync-rand-dasd
               SYNC    FROM DASD (S) = pages-sync-seq-dasd
               ASYNC   FROM DASD     = pages-async-dasd
               SYNC    FROM GBP (R)  = pages-sync-rand-gbp 
               SYNC    FROM GBP (S)  = pages-sync-seq-gbp 
               ASYNC   FROM GBP      = pages-async-gbp 
             PAGES MOVED INTO SIMULATED BUFFER POOL = pages-to-sim-bp 
             TOTAL AVOIDABLE SYNC I/O DELAY = sync-io-delay MILLISECONDS

pages-sync-rand-dasd

The number of pages accessed randomly by avoidable synchronous read I/O from disk.

pages-sync-seq-dasd

The number of pages accessed sequentially by avoidable synchronous read I/O from disk.

pages-async-dasd

The number of pages prefetched by avoidable asynchronous read I/O from disk.

pages-sync-rand-gbp

The number of pages accessed randomly by avoidable synchronous read from the group buffer pool..

pages-sync-seq-gbp

The number of pages accessed sequentially by avoidable synchronous read from the group buffer pool.

pages-async-gbp

The number of pages accessed by avoidable asynchronous read from the group buffer pool.

pages-to-sim-bp

The number of pages that were logically moved from the virtual buffer pool into the simulated buffer pool.

sync-io-delay

The total time in milliseconds that the buffer pool simulation determined would be spent waiting for synchronous read I/O from disk.

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.

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

• DSNB250E
• Displaying the logical page list
• Characteristics of pages that are in error

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.

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.

Note: There are two sections to report synchronous I/O delays. The SYNCHRONOUS I/O DELAYS section shows statistics for all I/Os. The SYNCHRONOUS I/O DELAYS WITH ZHYPERLINK section show statistics only for those requests which used zHyperlink.

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 microseconds for pages in the data set.

mxd

The maximum I/O delay in microseconds for pages in the data set.

tpg

The total number of pages that are read or written for the data set.

SYNCHRONOUS I/O DELAYS WITH ZHYPERLINK -
             AVERAGE DELAY         = avdz
             MAXIMUM DELAY         = mxdz
             TOTAL PAGES           = tpgz

avdz

The average I/O delay in microseconds for pages in the data set when zHyperLink is used.

mxdz

The maximum I/O delay in microseconds for pages in the data set when zHyperLink is used.

tpgz

The total number of pages that are read or written for the data set when zHyperLink is used.

Related information

• Read operations and prefetch I/O

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 microseconds for pages in the data set.

mxd

The maximum I/O delay in microseconds 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.

The output includes the number of simulated pages in the simulated 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 simulated pages in the simulated buffer pool is 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.

DSNB457I - NUMBER OF PAGES IN THE SIMULATED BUFFER POOL -
           CURRENT       =        scount   MAX           =        mscount

CURRENT = scount

The number of pages from the data set that are currently simulated in the simulated buffer pool.

MAX = mscount

The maximum number of pages from the data set that have been simulated in the simulated buffer pool since the last DISPLAY BUFFERPOOL command with the LSTATS option was issued.

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.

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.

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.

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.

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-------------------

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

• Claims and drains

Message DSNB546I describes the frame size allocation status of the buffer pool. If the specified number of buffers with the specified frame size are not available, Db2 allocates some of the buffers with a different frame size. In that case, Db2 issues multiple instances of this message to show the number of buffers that are allocated with each frame size.

DSNB546I - PREFERRED FRAME SIZE preferred-size buffer-count BUFFERS USING frame-size FRAME SIZE ALLOCATED  

preferred-size

The requested frame size. If you used the ALTER BUFFERPOOL command with the FRAMESIZE option, the specified FRAMESIZE value is displayed as preferred-size.

This value can be 4K, 1M, or 2 GB.

buffer-count

The number of buffers that are allocated with the frame-size value. This value might include storage frames that have been logically removed from the buffer pool, but which Db2 cannot yet free.

frame-size

The actual frame size that Db2 used for the buffers.

This value can be 4K, 1M, or 2 GB.

Message DSNB550I is displayed only after a buffer pool is allocated for which the requested FRAMESIZE and PGSTEAL values are FRAMESIZE(2G) and PGSTEAL(NONE).

DSNB550I - CURRENT PAGE STEALING METHOD = NONE 
           PAGE STEALING METHOD BEING USED = LRU

PGSTEAL(NONE) and FRAMESIZE(2G) are not compatible in Db2 12. If you specify these options together, Db2 issues message DSNB549I and uses the PGSTEAL(LRU) algorithm until the next allocation of the buffer pool. However, PGSTEAL(NONE) is recorded in the BSDS. To use PGSTEAL(NONE), specify FRAMESIZE(1M) or FRAMESIZE(4K). For more information, see Changed behavior for PGSTEAL(NONE) buffer pools in Storage release incompatibilities in Db2 12.

The DISPLAY THREAD output normally ends with message DSN9022I.

DSN9022I - DSNB1CMD '-DISPLAY BUFFERPOOL' NORMAL COMPLETION

Related information

• DSN9022I

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.