Trace fields for READS requests
A monitor program can call the READS function to request synchronous data from certain specific trace records.
Tip: 
IFCID 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.
The following trace records can be requested in READS calls to the instrumentation facility interface:IFCID 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.- 0001
- Statistical data on the systems services address space, including
- Task control block (TCB) and service request block (SRB) times for system services
- Database services, including DDF statistics
- Internal Resource Lock Manager (IRLM) address spaces
- Usage information by LPAR, Db2 subsystem, or Db2 address space
- CPU utilization
- Storage metrics
- 0002
- Statistical data on the database services address space (ssnmDBM1).
- 0104
- Information on the current active log data sets.
- 0106
- Static system parameters.
- 01241
- An active SQL snapshot that provides status information about:
- The process
- The SQL statement text
- The relational data system input parameter list (RDI) block
- Certain bind and locking information
You can obtain a varying amount of data because the request requires the process to be connected to Db2, have a cursor table allocated (RDI and status information is provided), and be active in Db2 (SQL text is provided if available). The SQL text that is provided does not include the SQL host variables, and is truncated at 4000 bytes.
For dynamic SQL, IFI provides the original SQL statement. The RDISTYPE field contains the actual SQL function taking place. For example, for a SELECT statement, the RDISTYPE field can indicate that an open cursor, fetch, or other function occurred. For static SQL, you can see the DECLARE CURSOR statement, and the RDISTYPE indicates the function. The RDISTYPE field is mapped by mapping macro DSNXRDI.
- 01291
- Returns one or more VSAM control intervals (CIs) that contain Db2 recovery log records. You can use IFI to return these records for use in remote site recovery.
- 01471
- An active thread snapshot that provides a status summary of processes at a Db2 thread or non-thread level.
- 01481
- An active thread snapshot that provides more detailed status of processes at a Db2 thread or non-thread level.
- 01491
- Information that indicates who (the thread identification token) is holding locks and waiting for locks on a particular resource and hash token. The data is in the same format as IFCID 0150.
- 01501
- All the locks held and waited on by a given user or owner (thread identification token).
- 0185
- Data descriptions for each table for which captured data is returned on this DATA request. IFCID 0185 data is only available through a propagation exit routine that is triggered by Db2.
- 01991
- Information about buffer pool usage by Db2 data sets. Db2 reports this information for an interval that you specify in the DATASET STATS TIME field of installation panel DSNTIPN. At the beginning of each interval, Db2 resets these statistics to 0.
- 0202
- Dynamic system parameters.
- 0217
- Storage detail record for the database services address space (ssnmDBM1).
- 0225
- Storage summary record for the database services address space (ssnmDBM1).
- 0230
- Global statistics for data sharing.
- 02341
- User authorization information.
- 02541
- Group buffer pool usage in the data sharing group.
- 0306
- Returns compressed or decompressed log records in both a data sharing or non data-sharing environment. For more information about using IFCID 0306 to read log records, see Reading complete log data (IFCID 0306).
- 03161
- Returns information about the contents of the dynamic statement cache. The IFI application can request information for all statements in the cache, or provide qualification parameters to limit the data returned. Db2 reports the following information about a cached statement:
- A statement name and ID that uniquely identify the statement
- If IFCID 318 is active, performance statistics for the statement
- The first 60 bytes of the statement text
- 0317
- Returns the complete text of an SQL statement in the dynamic statement cache and the PREPARE attributes string. You must provide the statement name and statement ID from IFCID 316 output. For more information about using IFI to obtain information about the dynamic statement cache, see Monitoring the dynamic statement cache with READS calls.
- 0346
- Monitors all invoked packages for a Db2 thread.
- 0369
- Returns aggregated accounting statistics by connection type.
- 0373
- Returns a pointer to the DSNHDECP load module or a user specified application defaults module that was loaded by the attached subsystem when Db2 was started.
- 0401
- Returns information about static SQL statements that are tracked in the in the EDM pool. The statement identified can be used to query the catalog to identify the statement text. Data is accumulated when IFCID 400 is activated. For more information about using IFI to obtain information about static SQL statements, see Monitoring static SQL statements with READS calls
- 0402
- Returns information about any system profile warning or exception condition that occurs in a statistics interval. The fields in this trace record maps to the QW0402 DSECT in the DSNDQW05 macro.
Notes:
- The following IFCID fields are available only through
READS calls:
- 0124
- 0129
- 0147
- 0148
- 0149
- 0150
- 0199
- 0234
- 0254
Finding trace field (IFCID) descriptions
You can find descriptions of trace records in the IFCID flat file (DSNWMSGS). 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).
