IFCID changes in Db2 13

Db2 13 introduces changes to various instrumentation facility component identifier (IFCID) trace fields.

Important: Db2 13 introduces continuous delivery of new capabilities and enhancements in function levels. Most new capabilities become available only after activation of the Db2 13 function level that introduces them, or when applications run with the corresponding application compatibility level. For more information, see Activating Db2 13 function levels.
Tip: Start of changeIFCID numbers are often presented in Db2 and its documentation with three or four digits and leading zeros. For example, you might find: "IFCID 1," "IFCID 001," or "IFCID 0001." However, you can assume that these references each have the same meaning.End of change

New trace records

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The following table gives an overview of new IFCIDs. Serviceability trace records are not included.

IFCID Trace type and class
Mapping macro
 Description
396 Statistics class 3, Performance class 6 DSNDQW05 Records information about abnormal index splits
415 Statistics class 4 DSNDQW05 Records information about authentication tokens that could not be processed by RACF
416 Audit class 12 DSNDQW05 Records the REST cross-origin resource sharing exception trace
417 Statistics class 10, Statistics class 11 DSNDQW05 Records detailed client inventory information for remote applications that connect to a Db2 subsystem
437 Performance class 3 DSNDQW05 Records information about the SET CURRENT LOCK TIMEOUT SQL statement
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Changes to selected trace records

Begin program-specific programming interface information.

The following table gives an overview of changes to specific IFCIDs. Changes to IFCID 106, the system parameters record, and changes to serviceability trace records are not included.

IFCID Function level APAR Enhancement and description of changes
1 V13R1M100   DBAT availability improvements:

The value in field QDSTNDBA, which records the number of times that DBATs were created, might increase significantly after migration to Db2 13. In previous Db2 releases, field QDSTNDBA excluded DBATs that were created to replace disconnected, pooled DBATs that were terminated because they reached their reuse limit. Starting in Db2 13, the count in field QDSTNDBA includes all DBATs that were created.

Fields are added to record:

  • The current number of DBATs (distributed server threads) that are active because the associated packages were bound with KEEPDYNAMIC(YES).
  • The maximum number of DBATs that are active because the associated packages were bound with KEEPDYNAMIC(YES).
  • The number of DBATs that were terminated since DDF was started.
  • The number of DBATs that were terminated because they remained in the pool longer than the value specified by the POOLINAC subsystem parameter.
  • The number of DBATs that were terminated because they were reused more times than the reuse limit.
  • The number of times that threads that were used by connections from the remote site were terminated because they remained in the pool longer than the value specified by the pool thread timeout value.
  • The number of times that threads that were used by connections from the remote site were terminated because the TCP/IP socket was closed due to a connection loss.
1 V13R1M100   Increase number of latch classes to 64:

The following changes are made:

  • In the data that is mapped by DSNDQVLS, fields are added for latch classes 33 to 64.
  • Field QSST_P64DISYES is moved to the end of the data that is mapped by DSNDQSST.
1 V13R1M500 PH47626 Improved DBAT status for MONITOR THREADS profiles in DISPLAY THREAD output:

The following changes are made:

  • The current number of DBATs that were suspended due to a profile exception.
  • The maximum number of DBATs that were suspended due to a profile exception.
1, 365 V13R1M505 PH55599 RACF identity token support:

The following change is made:

  • A field is added to record the number of connections from the remote site that used an authentication token.
1 V13R1M505 PH56369 Separate location statistics from STATIME_MAIN:

The following change is made:

  • A field value is added to record the trace destination that is used for IBM Db2 AI for z/OS traces.
2 V13R1M100 PH55153 Changes to the maximum number of repeated sections in certain IFCID 2 records:

The following changes are made:

  • More than one IFCID 2 record can be generated for accelerator services statistics. The maximum number of QWS10RBO sections (accelerator services system statistics sections) in the initial IFCID 2 record is two. If additional Q8ST data exists, it is written in an additional IFCID 2 record that contains only data section 11 Q8ST data.
  • The maximum number of QWS10R7O sections (group buffer pool statistics sections) in the initial IFCID 2 record is decreased from 25 to 15.
2 V13R1M504 PH55497 Minimize the impact of package invalidation

Fields are added to record:

  • The number of autobind phase-in attempts
  • The number of successful autobind phase-in processes
  • The number of autobind phase-in requests in the service task's queue
2, 3 V13R1M100   Reduce RACF contention:

Fields are added to record:

  • The number of checks for the plan execute privilege that were made using the plan authorization cache and were unsuccessful because an applicable entry was not found in the cache.
  • The number of times that Db2 overwrote an authorization ID in the plan authorization cache.
2, 3 V13R1M500   Application timeout and deadlock control:

Fields are added to record:

  • The number of times that a SET CURRENT LOCK TIMEOUT statement was executed.
  • The number of times that the CURRENT LOCK TIMEOUT special register was set from a profile table.
2, 3, 148 V13R1M504 PH55497 Minimize the impact of package invalidation

Fields are added to record:

  • The number of incremental binds that occurred due to invalidated statements
  • The number of incremental binds with APREUSE that Db2 retried
3 V13R1M100   Increase number of latch classes to 64:

The following changes are made:

  • Field QLLLLC is expanded from one byte to two bytes.
3 V13R1M100   Accounting information on the longest wait times for common suspension types:

A section is added to record the following thread-level wait time information:

  • The longest wait for a lock, latch, or synchronous or asynchronous I/O (part 1 of the longest wait time information)
  • The longest service task wait time (part 2 of the longest wait time information)
  • The longest wait for a page latch (part 3 of the longest wait time information)

This information can simplify the task of diagnosing performance issues that are due to excessive wait times for resources.
3 V13R1M100 PH46371 Enhancement to accounting information on the longest wait times for common suspension types:
  • Field QLLLTYP is added to identify the various types of part 1 wait times.
3 V13R1M100 PH46372 Enhancement to accounting information on the longest wait times for common suspension types:
  • Longest wait time information is written for accounting rollup records. Accounting rollup records are generated when subsystem parameter ACCUMACC is set to a value greater than 1.
3 V13R1M500 PH51892 SQL Data Insights support:
Fields are added to record:
  • Elapsed time, CPU time, and zIIP time that Db2 spent while processing SQL Data Insights functions.
  • The number of times that SQL Data Insights functions were invoked.
21 V13R1M504 PH55497 A flag is added for the locked resource type field to indicate that the lock is an autobind phase-in lock.
51, 52, 56, 57, 148 V13R1M100   Increase number of latch classes to 64:

The following changes are made:

  • Fields QW0051LC, QW0052LC, QW0056LC, QW0057LC, and QW0148LC are expanded from one byte to two bytes.
172 V13R1M500   Application timeout and deadlock control:

A field is added to record:

  • For the process that is waiting for a resource, the source of the value that Db2 uses to determine the victim of a deadlock (worth value).

Existing long name fields are populated for client information such as such as workstation ID, user ID, and transaction ID.
196 V13R1M500   Application timeout and deadlock control:

Fields are added to record the following information about a lock request that times out:

  • For the thread that requests a lock and times out, the source of the timeout interval. The source is the IRLMRWT subsystem parameter, the CURRENT LOCK TIMEOUT special register, or an IRLM internal value.
  • For the thread that holds the lock, the source of the timeout interval that is set for the thread. The source is the IRLMRWT subsystem parameter, the CURRENT LOCK TIMEOUT special register, or an IRLM internal value.

Existing long name fields are populated for client information such as such as workstation ID, user ID, and transaction ID.
230, 254 V13R1M100   IBM z15 group buffer pool (GBP) residency time:

Fields are added to record:

  • The weighted average, in microseconds, of the elapsed time that a data area resides in a group buffer pool before the data area is reclaimed.
  • The weighted average, in microseconds, of the elapsed time that a directory entry resides in a group buffer pool before the directory entry is reclaimed.
319 V13R1M100 PH57811 A field is added to record the PROFILEID value when the QW0319PA field value is 'W' or 'E'.
376 V13R1M500   Change of the default MAXPARTITIONS for partition-by-growth table spaces to 254:

Function code 1315001 records when CREATE TABLESPACE or CREATE TABLE statements use a default MAXPARTITIONS value of 256 when the application compatibility level is V13R1M100, but use a default MAXPARTITIONS value of 254 when the application compatibility level is V13R1M500 or later. A record with function code 1315001 is written only when the application compatibility level is V13R1M100.
389 V13R1M500 PH51565 A field is added to record the FTB factor, which is a calculated value that Db2 uses to identify indexes that might benefit from fast index traversal.
402 V13R1M100 PH50729 The values of the following fields are reset to zero when a new profile is enabled, or an existing profile's warning or exception threshold is changed:
  • QW0402TE
  • QW0402TQ
  • QW0402TF
  • QW0402TW
  • QW0402CE
  • QW0402CW
  • QW0402OE
  • QW0402OW

An additional location for the IFCID flat file (DSNWMSGS)

You can now find DSNWMSGS in either of the following locations:
  • The most current version of DSNWMSGS is available only for clients who have Db2 13 for z/OS licenses. The information is in a PDF file. To locate this information, see Db2 13 for z/OS IFCID flat file (DSNWMSGS).
  • An older version of DSNWMSGS is available in the prefix.SDSNIVPD(DSNWMSGS) data set. You can use the TSO or ISPF browse function to look at the field descriptions in prefix.SDSNIVPD(DSNWMSGS), even when Db2 is down. If you prefer to look at the descriptions in printed form, you can use ISPF to print a listing of the data set.
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