IFCID 003 - Instrumentation Accounting Data
This topic shows detailed information about Record Trace - IFCID 003 - Instrumentation Accounting Data
.
Record Trace - IFCID 003 - Instrumentation Accounting Data
The field labels shown in the following sample layout of Record Trace - IFCID 003 - Instrumentation Accounting Data
are described in the following section.
INSTRUMENTATION ACCOUNTING DATA
CLASS 1 BEGINNING STORE CLOCK TIME 10/20/08 08:36:54.206466 ENDING STORE CLOCK TIME 01/02/08 00:00:01.179628
ELAPSED TIME N/C MVS TCB TIME 0.05
BEGINNING MVS TCB TIME 0.000011 ENDING MVS TCB TIME 0.053044
STORED PROC ELAPSED TIME 0.000000 CONVERSION FACTOR 818
STORED PROCEDURE TCB TIME 0.000000 PAR.TASKS: 10 PAR.TOKEN: X'1FB2AFD0'
UDF ELAPSED TIME 0.000000 COMMITS : 6 SVPT REQ.: 0
UDF TCB TIME 0.000000 ROLLBACKS: 4 SVPT RLB.: 0
NETWORK ID VALUE 'BLANK' PROGRAMS : 1 SVPT REL.: 0
REASON ACCT INVOKED: 'ACCUM DATA FOR DDF/RRSAF AND THRESHOLD REACHED FOR END USER OCCURRENCES'
SE CPU TIME 0.000000
CLASS 1/2 STORED PROC SE TCB TIME 0.000000
STORED PROC ELAPSED TIME 0.000000
STORED PROC CP ELAPSED TIME 0.000000
UDF NF SE CPU TIME 0.000000
UDF NF ELAPSED TIME 0.000000
UDF NF CP CPU TIME 0.000000
CLASS 2 DB2 ELAPSED TIME 5.757953 DB2 ENTRY/EXIT EVENTS 2512
TCB TIME 0.448220 NON-ZERO CLASS 2 YES
STORED PROC ELAPSED TIME 0.000000 CLASS 2 DATA COLLECTED YES
STORED PROCEDURE TCB TIME 0.000000 STORED PROC. ENTRY/EXITS 0
UDF ELAPSED TIME 0.000000 UDF SQL ENTRY/EXITS EVENTS 0
CP CPU TIME UDF 0.000000 SE CPU TIME 1.548725
TRIG ELAP TIME UNDER ENCLAVE 0.000000 SE ELIGIBLE CP CPU TIME 0.000000
TRIG TCB TIME UNDER ENCLAVE 0.000000 QWACTRTT_ZIIP 0.000000
TRIG ELAP TIME NOT UNDER ENCLAVE 0.000000 ELAPSED TIME ELIGIBLE FOR ACCEL 0.000000
TRIG TCB TIME NOT UNDER ENCLAVE 0.000000 CP CPU TIME ELIGIBLE FOR ACCEL 0.000000
SE CPU TIME ELIGIBLE FOR ACCEL 0.000000
SQL DATA INSIGHTS ELAPSED TIME 0.065535 SQL DATA INSIGHTS CPU TIME 0.065535
SQL DATA INSIGHTS ENTRY/EXITS 65535 SQL DATA INSIGHTS ZIIP TIME 0.065535
CLASS 3 ACCU LOCK ELAPSED TIME 0.000000 WAIT TRACE EVENTS 0
DB2 LATCH SUSP TIME 0.000381 LATCH WAIT TRACE EVENTS 12
SYNCHRONOUS I/O SUSP TIME 0.000000 SYNCHRONOUS I/O SUSP EVENTS 0
LOG WRITE I/O SUSP TIME 0.015757 LOG WRITE I/O SUSP EVENTS 12
OTHER READ SUSP TIME 0.000000 OTHER READ SUSP EVENTS 0
OTHER WRITE SUSP TIME 0.000000 OTHER WRITE SUSP EVENTS 0
UPDATE COMMIT SUSP TIME 0.001776 UPDATE COMMIT SUSP EVENTS 8
PAGE LATCH(DB2+IRLM) SUSP TIME 0.000000 PAGE LATCH(DB2+IRLM) SUSP EVENTS 0
NOTIFY MESSAGES SUSP TIME 0.000000 NOTIFY MESSAGES EVENTS 0
GLOB CONT PARENT L-LOCK TIME 0.000000 GLOB CONT PARENT L-LOCK EVENTS 0
GLOB CONT CHILD L-LOCK TIME 0.000000 GLOB CONT CHILD L-LOCK EVENTS 0
GLOB CONT OTHER L-LOCK TIME 0.000000 GLOB CONT OTHER L-LOCK EVENTS 0
GLOB CONT PGSET/PART P-LOCK TIME 0.000000 GLOB CONT PGSET/PART P-LOCK EVENTS 0
GLOB CONT PAGE P-LOCK TIME 0.000000 GLOB CONT PAGE P-LOCK EVENTS 0
GLOB CONT OTHER P-LOCK TIME 0.000000 GLOB CONT OTHER P-LOCK EVENTS 0
SCHED. STOR PROC SUSP TIME 0.000000 STORED PROCEDURE EVENTS 0
SCHED. UDF SUSP TIME 0.000000 NON-ZERO CLASS 3 YES
TCP/IP LOB XML TIME 0.000000 TCP/IP LOB XML EVENTS 0
ACCELERATOR SUSP TIME 0.000000 ACCELERATOR EVENTS 0
AUTON PROC WAIT TIME 0.000000 AUTON PROC EVENTS 0
PARALLEL QUERY SYNC WAIT TIME 0.000000 PARALLEL QUERY SYNC WAIT EVENTS 0
CLASS 3 DATA COLLECTED YES
CLASS 7 DATA COLLECTED YES CLASS 8 DATA COLLECTED YES
MAX WORKFILE BLOCKS 0 CURR WORKFILE BLOCKS 0
WLM SERVICE CLASS: N/P PARALLEL CHILDS ROLLED INTO RECORD: 0
ROLLUP DATA FOR PARALLEL CHILD TASKS NO PARALLEL QUERY ROLLUP DATA: YES
AUTON PROC ROLLUP DATA: YES
- CLASS 1: BEGINNING STORE CLOCK TIME
-
The beginning store clock value for the period covered by the accounting record. You can determine the elapsed time of the application by subtracting this field from the ending store clock value (QWACESC). Threads that do not terminate (such as CICS primed threads and IMS wait-for-input message regions) can have an ending clock value that includes the time during which the thread was inactive and waiting for work.
If a roll-up trace record is written with accumulated counter data, QWACBSC represents the earliest begin store clock value for a thread that has rolled data into the record. In this case, QWACESC shows the accumulated elapsed time.
Field Name: QWACBSC
- CLASS 1: ENDING STORE CLOCK TIME
-
The ending store clock value. You can use this field with the beginning store clock value (QWACBSC) to determine the elapsed time of an application.
If a roll-up record is written with accumulated accounting data, QWACESC contains the accumulated elapsed time. In Accounting Trace reports, the elapsed time is shown under CLASS 1: NONNESTED ELAPSED TIME and the END TIME is reported as N/P, because QWACESC does not contain a timestamp. In the Accounting FILE GENERAL table, the accumulated elapsed time QWACESC is stored in column CLASS1_ELAPSED and column CLASS1_TIME_END contains a timestamp 1900-01-01-00.00.00.000000.
Field Name: QWACESC
- CLASS 1: ELAPSED TIME
-
The time covered by this accounting record. If the time cannot be calculated or the value is negative, N/C is printed in this field. Calculated from the DB2 field QWACESC - QWACBSC. For a rollup record elapsed time will be equal to QWACESC. QWACESC contain the accumulated elapsed time for all child tasks or all DDF/RRSAF threads rolled into the record.
Field Name: RT0003ET
- CLASS 1: MVS TCB TIME
-
The amount of MVS CPU time used. If the time cannot be calculated or the value is negative, N/C is printed in this field. Calculated from the DB2 field QWACEJST - QWACBJST. For a rollup record MVS CPU time will be equal to QWACEJST. QWACEJST contain the accumulated CPU time for all child tasks or all DDF/RRSAF threads rolled into the record.
Field Name: RT0003TT
- CLASS 1: BEGINNING MVS TCB TIME
-
The beginning MVS CPU time for all environments (such as: CICS, IMS, RRSAF, or TSO). This CPU time is not affected by an IBM specialty engine. Binary zero means that no time value is available.
Field Name: QWACBJST
- CLASS 1: ENDING MVS TCB TIME
-
The ending MVS CPU time. This CPU time is not affected by an IBM specialty engine. Binary zero means that no time value is available.
Field Name: QWACEJST
- CLASS 1: STORED PROC ELAPSED TIME
-
The total elapsed time spent by the allied agent in stored procedures.
A stored procedure may initiate a trigger or invoke a user-defined function. The time spent there is not included in this counter.
Note: This field is not normally shown in the short layouts but can be included with UTR.Field Name: QWACSPEA
- CLASS 1: CONVERSION FACTOR
-
The CPU service unit conversion factor allows for converting CPU time to a common unit, which is called service unit (SU) . The conversion factor depends on the machine being used. With the SU, you can add up CPU execution times across multiple DB2 systems running on different machines. It is a raw value for RECORDTRACE and Accounting FILE data. For Accounting SAVE data it cannot be determined.
Field Name: QWACSUCV
- CLASS 1: STORED PROCEDURE TCB TIME
-
The TCB time accumulated in DB2 for processing SQL CALL statements in the stored procedures or WLM address space. This time is only calculated if accounting class 1 is active.
SQL procedure times are included in this time if the SQL procedure was called on a nested task and was not invoked by the main application execution unit. This time does not include CPU time consumed on an IBM specialty engine.
Field Name: QWACSPCP
- CLASS 1: PAR.TASKS
-
The number of parallel child agents, or Accounting intervals rolled up, or autonomous procedures rolled up. The value depends on the record type:
- For a non-rollup parent record, this value is the number of parallel child agents that were created.
- For a non-rollup child agent record, this value is 0.
- For a parallel query rollup record, this value is the number of parallel child agents rolled into the record.
- For a DDF/RRSAF rollup record, this value is the number of Accounting intervals that were rolled into the record for the corresponding end user.
- For an autonomous procedure rollup record, this value is the number of autonomous procedures rolled into the record.
Field Name: QWACPCNT
- CLASS 1: PAR.TOKEN
-
Token used to correlate parallel task, utility task records, or autonomous procedure rollup records with the records of the originating task or main utility task.
Field Name: QWACPACE
- CLASS 1: UDF ELAPSED TIME
-
The total elapsed time spent by the allied agent in UDF functions processed in a DB2 stored procedure or WLM address space. A user-defined function may initiate a trigger or invoke a stored procedure. Non-inline UDF times are included in this time if the native UDF was called on a nested task and was not invoked by the main application execution unit.
This time includes time executing SQL.
Note: With user-tailored reporting (UTR) you can include this field in the short layouts of Accounting.Field Name: QWACUDEA
- CLASS 1: COMMITS
-
The number of successful two-phase (units of recovery) or single-phase (syncs) commit requests. It indicates the number of units of recovery that are completed successfully, and for which the associated commit duration locks were released. It represents the total number of commit requests processed by the DB2 subsystem, whether the request was an explicit or implicit external request from an IMS or a CICS connection, or an implicit internal request within DB2 when DB2 was the commit coordinator or conducted read-only commit processing as a commit participant on phase-1 calls from an IMS or CICS connection.
For parallel queries, only the commits from the initiating (parent) thread are recorded by this counter.
Field Name: QWACCOMM
- CLASS 1: SVPT REQ.
-
The number of named SAVEPOINTs set within a transaction.
Field Name: QWACSVPT
- CLASS 1: UDF TCB TIME
-
The accumulated CPU time used to satisfy UDF requests processed in a DB2 stored procedure or WLM address space. Non-inline UDF times are included in this time if the native UDF was called on a nested task and was not invoked by the main application execution unit.
This time is only calculated if accounting class 1 is active.
This time does not include the CPU time consumed on an IBM specialty engine.
Field Name: QWACUDCP
- CLASS 1: ROLLBACKS
-
The number of rollback requests. This is the number of units that were backed out, including rollbacks from attaches.
Special Considerations: This field contains the number of:- Application program abends
- Application rollback requests
- Application deadlocks on database records
- Applications canceled by operator
- Thread abends due to resource shortage
Field Name: QWACABRT
- CLASS 1: SVPT RLB.
-
The number of ROLLBACK TO SAVEPOINT statements executed.
Field Name: QWACRBSV
- CLASS 1: NETWORK ID VALUE
-
The network ID. It is used with IMS and CICS.
Field Name: QWACNID
- CLASS 1: PROGRAMS
-
The number of packages or DBRMs for which accounting data was collected.
Field Name: QWACPKGN
- CLASS 1: SVPT REL.
-
The number of RELEASE SAVEPOINT statements executed.
Background and Tuning Information
Release savepoints as soon as possible. Outstanding savepoints block SQL operations that resolve remote locations. DB2 always releases outstanding savepoints when a transaction ends.
Field Name: QWACRLSV
- CLASS 1: REASON ACCT INVOKED
-
The reason for termination, that is, for producing a DB2 accounting record.
Field Name: QWACRINV
- CLASS 1: SE CPU TIME
-
The accumulated CPU time that is consumed while running on an IBM specialty engine in all environments. This value may be 0 when QWACRINV is greater than or equal to 20.
Field Name: QWACCLS1_ZIIP
- CLASS 1/2 STORED PROC SE TCB TIME
-
The accumulated CPU time that is consumed while running stored procedure requests on the main application execution unit on an IBM specialty engine. As these SPs run entirely within DB2, this time represents class 1 and class 2 time.
Field Name: QWACSPNF_ZIIP
- CLASS 1/2 STORED PROC ELAPSED TIME
-
The accumulated elapsed time that is consumed on an IBM specialty engine for executing stored procedure requests on the main application execution unit. As these stored procedures run entirely in DB2, this time represents class 1 and class 2 time.
Field Name: QWACSPNF_ELAP
- CLASS 1/2 STORED PROC CP ELAPSED TIME
-
The accumulated CPU time that is used for executing stored procedure requests on the main application execution unit. This time does not include the time that is consumed on an IBM specialty engine. As these stored procedures run entirely in DB2, this time represents class 1 and class 2 time.
Field Name: QWACSPNF_CP
- CLASS 1/2 UDF NF SE CPU TIME
-
Accumulated CPU time consumed executing user-defined functions on the main application execution unit on an IBM specialty engine. Since these UDFs run entirely within DB2, this time represents class 1 and class 2 time.
Field Name: QWACUDFNF_ZIIP
- CLASS 1/2 UDF NF ELAPSED TIME
-
Accumulated elapsed time consumed executing user-defined functions on the main application execution unit. Since these UDFs run entirely within DB2, this time represents class 1 and class 2 time.
Field Name: QWACUDFNF_ELAP
- CLASS 1/2 UDF NF CP CPU TIME
-
Accumulated CPU time consumed executing user-defined functions on the main application execution unit. This time does not include CPU consumed on an IBM specialty engine. Since these UDFs run entirely within DB2, this time represents class 1 and class 2 time.
Field Name: QWACUDFNF_CP
- CLASS 2: DB2 ELAPSED TIME
-
The class 2 elapsed time for nonnested activity accumulated in DB2 for the allied agent. This time does not include the time spent in DB2 processing SQL statements issued by stored procedures, user-defined functions, or triggers.
Special Considerations- The time for most thread allocation and certain abend conditions is not reflected in this time.
- The elapsed time for distributed processing is included in the elapsed time of allied-distributed threads.
- In query CP, sysplex query, or utility parallelism, this is the time shown in the originating record, which overlaps the elapsed times shown in the parallel records.
Note: This field is not normally shown in the short layouts but can be included with UTR.Field Name: QWACASC
- CLASS 2: DB2 ENTRY/EXIT EVENTS
-
The total number of DB2 entry and exit events processed by the allied address space to calculate the elapsed time in DB2 and the processor time.
This counter does not include the SQL entry and exit events processed by stored procedures.
Field Name: QWACARNA
- CLASS 2: TCB TIME
-
The accumulated MVS CPU time that is spent in DB2. This CPU time does not include the:
- CPU time that is consumed on an IBM specialty engine
- CPU time that is consumed while processing SQL statements in a stored procedure
Field Name: QWACAJST
- CLASS 2: NON-ZERO CLASS 2
-
This data section shows whether there is nonzero accounting class 2 data. Yes indicates that accounting class 2 or 7 was active during the life of the agent when a class 2 event occurred.
Field Name: QWACCLS2
- CLASS 2: STORED PROC ELAPSED TIME
-
The total elapsed time that the allied agent spent executing SQL in the stored procedures or WLM address space.
A stored procedure may initiate a trigger or invoke a user-defined function this time is not included in this counter.
Note: This field is not normally shown in the short layouts but can be included with UTR.Field Name: QWACSPEB
- CLASS 2: DATA COLLECTED
-
The accounting class 2 data was being collected when this accounting record was written.
Field Name: QWACCL2O
- CLASS 2: STORED PROCEDURE TCB TIME
-
The TCB time accumulated in DB2 for processing SQL statements issued by stored procedures. This time is only calculated if accounting class 2 is active.
Field Name: QWACSPTT
- CLASS 2: STORED PROC. ENTRY/EXITS
-
The number of SQL entry or exit events performed by stored procedures. This number is only calculated if accounting class 2 is active.
Field Name: QWACSPNE
- CLASS 2: UDF ELAPSED TIME
-
The total elapsed time spent by the allied agent executing SQL using UDF requests processed in a DB2 stored procedure or WLM address space. A user-defined function may initiate a trigger or invoke a stored procedure. Any time spent there is not included in this counter. This time includes time needed to connect and disconnect the UDF task. Non-inline UDF times are included in this time if the native UDF was called on a nested task and was not invoked by the main application execution unit.
Note: With user-tailored reporting (UTR) you can include this field in the short layouts of Accounting.Field Name: QWACUDEB
- CLASS 2: UDF SQL ENTRY/EXITS EVENTS
-
The number of SQL entry/exit events performed by user-defined functions.
This is only calculated if accounting class 2 is active.
Field Name: QWACUDNE
- CLASS 2: CP CPU TIME UDF
-
The accumulated CPU time consumed in DB2 when processing SQL statements that were issued by UDF(s) processed in a DB2 stored procedure or WLM address space.
This time also includes the DB2 time required to connect and disconnect the UDF task. Non-inline UDF times are included in this time if the native UDF was called on a nested task and was not invoked by the main application execution unit.
This time is a subset of QWACUDCP and is only calculated if accounting class 2 is active.
This time does not include CPU consumed on an IBM specialty engine.
Field Name: QWACUDTT
- CLASS 2: SE CPU TIME
-
The accumulated and consumed class 2 time on an IBM specialty engine.
Field Name: QWACCLS2_ZIIP
- CLASS 2: TRIG ELAP TIME UNDER ENCLAVE
-
The accumulated elapsed time used for executing triggers under an enclave.
Field Name: QWACTREE
- CLASS 2: SE ELIGIBLE CP CPU TIME
-
HFSHORT
Field Name: QWACZIIP_ELIGIBLE
- CLASS 2: TRIG TCB TIME UNDER ENCLAVE
-
The accumulated CPU time used for executing triggers on a nested task. This time does not include CPU consumed on an IBM specialty engine.
Field Name: QWACTRTE
- CLASS 2: QWACTRTT_ZIIP
-
Accumulated CPU time consumed on an IBM specialty engine while running triggers on nested task or main application execution unit.
Field Name: QWACTRTT_ZIIP
- CLASS 2: TRIG ELAP TIME NOT UNDER ENCLAVE
-
The accumulated elapsed time used when executing under the control of a trigger. This does not include the time used while in user-defined functions or stored procedures that are called from the trigger.
Field Name: QWACTRET
- CLASS 2: ELAPSED TIME ELIGIBLE FOR ACCEL
-
The accumulated elapsed time spent processing SQL in DB2 that may be eligible for execution on an accelerator.
Field Name: QWAC_ACCEL_ELIG_ELA
- CLASS 2: TRIG TCB TIME NOT UNDER ENCLAVE
-
The accumulated TCB time that is used when running under the control of a trigger. This does not include the time that is used while running in user-defined functions or stored procedures that are called from the trigger.
This CPU time does not include the CPU time that is consumed on an IBM specialty engine.
Field Name: QWACTRTT
- CLASS 2: CP CPU TIME ELIGIBLE FOR ACCEL
-
The accumulated CPU time spent processing SQL in DB2 that may be eligible for execution on an accelerator.
Field Name: QWAC_ACCEL_ELIG_CP
- CLASS 2: SE CPU TIME ELIGIBLE FOR ACCEL
-
The accumulated CPU time consumed on an IBM specialty engine while processing SQL in DB2 that may be eligible for execution on an accelerator.
Field Name: QWAC_ACCEL_ELIG_SE
- CLASS 2: SQL DATA INSIGHTS ELAPSED TIME
-
The accumulated elapsed time spent processing SQL Data Insights functions. This time is included in Class 2 elapsed time.
Field Name: QWAC_AIDB_FNS_ELAP
- CLASS 2: SQL DATA INSIGHTS CPU TIME
-
The accumulated CPU time spent processing SQL Data Insights functions. This time is included in Class 2 CPU time. It does not include CPU consumed on an IBM specialty engine.
Field Name: QWAC_AIDB_FNS_CP
- CLASS 2: SQL DATA INSIGHTS ZIIP TIME
-
The accumulated CPU time spent processing SQL Data Insights functions on an IBM specialty engine. This time is included in Class 2 CPU time.
Field Name: QWAC_AIDB_FNS_zIIP
- CLASS 2: SQL DATA INSIGHTS ENTRY/EXITS
-
The number of entry/exit events performed by SQL Data Insights functions.
Field Name: QWAC_AIDB_COUNT
- CLASS 3: ACCU LOCK ELAPSED TIME
-
The accumulated wait time because of local contention for locks. The term local contention is used to differentiate from global contention (which is reported in QWACAWTJ). Local contention does not require intersystem communication. The contention is detected and resolved entirely within this subsystem.
Field Name: QWACAWTL
- CLASS 3: WAIT TRACE EVENTS
-
The number of wait trace events processed for waits for local contention for locks.
Field Name: QWACARNL
- CLASS 3: DB2 LATCH SUSP TIME
-
The accumulated wait time because of latch contention.
Field Name: QWACAWLH
- CLASS 3: LATCH WAIT TRACE EVENTS
-
The number of wait trace events processed for waits for latch contention.
Field Name: QWACARLH
- CLASS 3: SYNCHRONOUS I/O SUSP TIME
-
The accumulated I/O elapsed wait time for database I/O done under this thread. This field is for synchronous I/O only. It includes synchronous read and write I/O. This value is an average.
Field Name: QWACAWTI
- CLASS 3: SYNCHRONOUS I/O SUSP EVENTS
-
The number of wait trace events processed for I/O.
Field Name: QWACARNE
- CLASS 3: LOG WRITE I/O SUSP TIME
-
The accumulated wait time for log write I/O.
This value is an average.
Field Name: QWACAWLG
- CLASS 3: LOG WRITE I/O SUSP EVENTS
-
The number of log I/O suspensions.
Field Name: QWACARLG
- CLASS 3: OTHER READ SUSP TIME
-
The accumulated waiting time due to a read I/O that performed under a thread other than the one being reported. The time does not represent the total duration of the subject read I/O. It includes:
- Sequential prefetch
- List prefetch
- Dynamic Prefetch
- Synchronous read I/O performed by a thread other than the one being reported
Field Name: QWACAWTR
- CLASS 3: OTHER READ SUSP EVENTS
-
The number of suspensions due to read I/O.
Field Name: QWACARNR
- CLASS 3: OTHER WRITE SUSP TIME
-
The accumulated waiting time due to a write I/O that performed under a thread other than the one being reported. This time does not represent the total duration of the subject write I/O. It includes:
- An asynchronous write I/O
- A synchronous write I/O performed by a thread other than the one being reported
- Frequent system checkpoints and low settings for deferred write thresholds
- When updating a page that is being written, the first thread wait is captured under Other Write I/O
- Other concurrent threads on the same DB2 subsystem will encounter Page latch suspension.
Field Name: QWACAWTW
- CLASS 3: OTHER WRITE SUSP EVENTS
-
The number of suspensions due to write I/O.
Field Name: QWACARNW
- CLASS 3: UPDATE COMMIT SUSP TIME
-
The accumulated wait time because of synchronous execution unit switch for DB2 Phase 2 commit, abort, or deallocation. This includes wait time for Phase 2 commit Log writes and database writes for LOB with LOG NO. For data sharing environment Page P-locks unlocks for updated pages and GBP writes.
Field Name: QWACAWTE
- CLASS 3: UPDATE COMMIT SUSP EVENTS
-
The number of update commit suspensions.
Field Name: QWACARNS
- CLASS 3: PAGE LATCH (DB2+IRLM) SUSP TIME
-
Page latch suspension could be due to concurrent threads that try to update a hot page that is frequently written because of a low deferred write threshold.
In the data sharing environment, within the same member, the first thread gets a P-lock (such as: Index leaf page P-Lock or P-Lock for Space map page or data page P-lock for Row level locking) during high INSERT activity. Performance trace for IFCID 226 and 227 provide more information for detailed analysis.
With a high number of concurrent threads, for subsequent threads in the same member for the same resource, contention is reported as encountering a page latch contention. Randomizing the Index key helps minimizing page latch contentions for the Index leaf page.
If the page latch is for a space map page and an incremental image copy is not used, use the DDL TRACKMOD NO option to avoid frequent updates to the space map page. The Member Cluster option reduces page latch contention for a space map page.
Field Name: QWACAWTP
- CLASS 3: PAGE LATCH (DB2+IRLM) SUSP EVENTS
-
The number of page latch wait trace events processed.
Field Name: QWACARNH
- CLASS 3: NOTIFY MESSAGES SUSP TIME
-
The accumulated elapsed waiting time due to suspensions caused by sending notify messages to other members in the data sharing group. Messages are sent, for example, when the database descriptors are changed due to DDL.
Field Name: QWACAWTG
- CLASS 3: NOTIFY MESSAGES EVENTS
-
The number of wait trace events processed for sending notify messages to other members in the data sharing group.
Field Name: QWACARNG
- CLASS 3: GLOB CONT PARENT L-LOCK TIME
-
The accumulated global contention wait time for parent L-locks.
A parent L-lock can be one of the following types:- Database
- Tablespace
- Table
- Partition
Background and Tuning Information
Performance Expert might adjust this value if the thread was suspended when performance data was gathered.
Field Name: QWACAWTJ
- CLASS 3: GLOB CONT PARENT L-LOCK EVENTS
-
The number of wait trace events processed for group-level contentions in a data sharing environment.
Field Name: QWACARNJ
- CLASS 3: GLOB CONT CHILD L-LOCK TIME
-
The accumulated global contention wait time for child L-locks.
A child L-lock type can be:- Page
- Row
Field Name: QWACAWTK
- CLASS 3: GLOB CONT CHILD L-LOCK EVENTS
-
The number of wait trace events processed for waits due to global contention for child L-locks.
Field Name: QWACARNK
- CLASS 3: GLOB CONT OTHER L-LOCK TIME
-
The accumulated global contention wait time for other L-locks. Global extend lock is acquired in exclusive mode by Inserters before an extend service task switch.
Field Name: QWACAWTM
- CLASS 3: GLOB CONT OTHER L-LOCK EVENTS
-
The number of wait trace events processed for waits due to global contention for other L-locks.
Field Name: QWACARNM
- CLASS 3: GLOB CONT PGSET/PART P-LOCK TIME
-
The accumulated global contention time for pageset and partition P-locks.
Field Name: QWACAWTN
- CLASS 3: GLOB CONT PGSET/PART P-LOCK EVENTS
-
The number of wait trace events processed for waits due to global contention for page set or partition P-locks.
Field Name: QWACARNN
- CLASS 3: GLOB CONT PAGE P-LOCK TIME
-
The accumulated global contention wait time for page P-locks.
Field Name: QWACAWTO
- CLASS 3: GLOB CONT PAGE P-LOCK EVENTS
-
The number of wait trace events processed for waits due to global contention for page P-locks.
Field Name: QWACARNO
- CLASS 3: GLOB CONT OTHER P-LOCK TIME
-
The accumulated global contention wait time for other P-locks. Includes suspension for Castout P-Locks and DBET locks. It could be because of Index Split processing which can be minimized if the Index key size is not large. If you can minimize the number of Index Keys in the Index, it will help to reduce the number of Index splits.
Field Name: QWACAWTQ
- CLASS 3: GLOB CONT OTHER P-LOCK EVENTS
-
The number of wait trace events processed for waits due to global contention for other P-locks.
Field Name: QWACARNQ
- CLASS 3: SCHED. STOR PROC SUSP TIME
-
The total elapsed waiting time for an available TCB before the stored procedure could be scheduled.
Field Name: QWACCAST
- CLASS 3: STORED PROCEDURE EVENTS
-
The number of wait trace events processed for an unavailable TCB needed for a stored procedure.
Field Name: QWACCANM
- CLASS 3: SCHED. UDF SUSP TIME
-
The total elapsed time spent waiting for an available TCB before the user-defined function could be scheduled.
Field Name: QWACUDST
- CLASS 3: NON-ZERO CLASS 3
-
CLASS 3 DATA IN THIS RECORD:Y/N
Field Name: QWACCLS3
- CLASS 3: TCP/IP LOB XML TIME
-
The accumulated wait time for TCP/IP LOB and XML (storing large object and XML) materialization.
Field Name: QWACALBW
- CLASS 3: TCP/IP LOB XML EVENTS
-
The number of wait trace events that were processed for waits for TCP/IP LOB and XML materialization.
Field Name: QWACALBC
- CLASS 3: ACCELERATOR SUSP TIME
-
The accumulated wait time for requests to an accelerator.
Field Name: QWACAACW
- CLASS 3: ACCELERATOR EVENTS
-
The number of wait trace events processed for requests to an accelerator.
Field Name: QWACAACC
- CLASS 3: AUTON PROC WAIT TIME
-
The accumulated time waiting for autonomous procedures to complete.
Field Name: QWAC_AT_WAIT
- CLASS 3: AUTON PROC EVENTS
-
The number of autonomous procedures that were executed:
- For non-rollup records, this value is the number of autonomous procedures that were executed.
- For a parallel query rollup record, this value is 0.
- For a DDF or RRSAF rollup record, this value is the number of autonomous procedures that were executed. These procedures are NOT counted in QWACPCNT.
- For autonomous procedures rollup records, this value is 0.
Field Name: QWAC_AT_COUNT
- CLASS 3: PARALLEL QUERY SYNC WAIT TIME
-
The accumulated time waiting for parallel queries to synchronize between parent and child tasks.
Field Name: QWAC_PQS_WAIT
- CLASS 3: PARALLEL QUERY SYNC WAIT EVENTS
-
The number of times the parallel query processing had to suspend because it was waiting for the synchronization of parent or child.
Field Name: QWAC_PQS_COUNT
- CLASS 3: CLASS 3 DATA COLLECTED
-
The accounting class 3 data was being collected when this accounting record was written.
Field Name: QWACCL3O
- CLASS 7: DATA COLLECTED
-
The accounting class 7 data was being collected when this accounting record was written.
Field Name: QWACCL7O
- CLASS 8: DATA COLLECTED
-
The accounting class 8 data was being collected when this accounting record was written.
Field Name: QWACCL8O
- MAX WORKFILE BLOCKS
-
The maximum number of work-file blocks that are used by this agent at any given point in time (traditional work-file blocks, declared global temporary tables (DGTT) and DGTT indexes) (DB2 field QWAC_WORKFILE_MAX).
Field Name: QWAC_WORKFILE_MAX
- CURR WORKFILE BLOCKS
-
The current number of work-file blocks that are used by this agent (traditional workfile use, declared global temporary tables (DGTT) and DGTT indexes).
Field Name: QWAC_WORKFILE_CURR
- WLM SERVICE CLASS
-
The MVS™ workload manager service class name. This field is used for database access threads on MVS 5.2 or later.
Field Name: QWACWLME
- PARALLEL CHILDS ROLLED INTO RECORD
-
The number of parallel child agents rolled into this record. The value depends on the record type:
- For all non-rollup records, this value is 0.
- For a parallel query rollup record, this value is the number of parallel child agents rolled into this record.
- For a DDF/RRSAF rollup record, this value is the number of parallel query child agents rolled into this record. These agents are NOT counted in QWACPCNT.
- For an autonomous procedure rollup record, this value is 0.
Field Name: QWAC_PT_COUNT
- ROLLUP DATA FOR PARALLEL CHILD TASKS
-
The field indicates whether to roll up accumulate query parallel task's accounting trace into originating task's accounting trace. Possible values are:
- YES
- Originating task cut an additional accounting trace record with all roll-up values from parallel tasks.
- NO
- Each parallel task will produce its own accounting trace record.
Field Name: QWACPARR
- PARALLEL QUERY ROLLUP DATA
-
This record contains parallel query rollup data.
Field Name: QWAC_RU_PARQRY
- AUTON PROC ROLLUP DATA
-
This record contains autonomous procedure rollup data.
Field Name: QWAC_RU_AT
