Introduction
DB2 statistics will be collected from SMF type 100. In this type of record, it doesn’t really matter the SMF subtype of the SMF record because DB2 uses another specification type to distinguish different SMF specializations.
In DB2 there is an identification named IFCID (Instrumentation Facility Component Identifier) each one with different data and purpose.
The statistics trace reports information about how much the Db2 system services and database services are used.
You can use the information that the statistics trace provides to plan Db2 capacity or to tune the entire set of active Db2 programs.
If you specify YES for the SMF STATISTICS entry in panel DSNTIPN, the statistics trace uses classes 1, 3, 4, 5, and 6 as the defaults. If the statistics trace is started using the START TRACE command, the statistics trace uses class 1 as the default.
The following table describes the Db2 statistics trace classes.
If you specify YES for the SMFSTAT subsystem parameter, the statistics trace starts automatically when you start Db2, and sends the default classes (classes 1, 3, 4, 5, and 6) statistics data to SMF. SMF records statistics data in both SMF type 100 and 102 records. IFCIDs 0001, 0002, 0202, 0225, 0230, and 0369 are of SMF type 100. All other IFCIDs in statistics trace classes are of SMF type 102.
When you specify CLASS(7) or IFCID(365) in a START TRACE or MODIFY TRACE command, Db2 writes IFCID 0365 records. These records are written to the specified destination of the statistics trace for remote locations that communicate with the subsystem. Statistics are generated only for those locations that have activity since the record was generated. The location statistics are written each time that the STATIME interval elapses. Statistics can be written for as many as 95 remote locations.
Db2 also writes statistics about all DRDA locations with the other default statistics trace data to a single SMF location named DRDA REMOTE LOCS, whenever other default statistics are written.
Statistics trace classesThe following table shows the IFCIDs that are activated for each statistics trace class.Table 1. Classes for Db2 statistics traceClassDescription of classActivated IFCIDs1Information about system services, database statistics, statistics for the database services address space (ssnmDBM1), and information about the system parameters that were in effect when the trace was started. This default class is also activated when you omit the CLASS keyword from the START TRACE command when you start the statistics trace.0001, 0002, 0105, 0106, 0202, 02252Installation-defined statistics record01523Deadlock, lock escalation, group buffer pool, data set extension information, and indications of long-running uncommitted reads, and active log space shortages.0172, 0196, 0250, 0258, 0261, 0262, 0313, 0330, 03374Db2 exceptional conditions.0173, 0191-0195, 0203-0210, 0235, 0236, 0238, 0267, 02685Db2 data sharing statistics record.02306Storage statistics for the Db2 subsystem.02257DRDA location statistics.03658Data set I/O statistics.01999Aggregated CPU and wait time statistics by connection type.036910 - 29Reserved. 30 - 32Available for local use.
Intervals for collecting Db2 statistics trace records
Db2 collects statistics trace records for the following IFCIDs at the interval specified by the STATIME and SYNCVAL subsystem parameters. For more information, see STATISTICS TIME field (STATIME subsystem parameter) and
STATISTICS SYNC field (SYNCVAL subsystem parameter)
0105 (Db2 performance trace)
0106 (system parameters)
0199 (data set statistics)
0365 (remote location statistics)
0402 (monitor profile warnings or exceptions)
Db2 collects statistics trace records for other IFCIDs at fixed one-minute intervals.
CSV I002C for SMF 100 IFCID 002, including PROD section and Datasharing Buffer Manager stats.
Fields
Stored in dbsi002c
| SMF Field | DB Column name | Type | Length | Description |
|---|---|---|---|---|
| DBSHD_RTY | record_type | Value is always I002C | ||
| DBSHD_SID | sid | SID | ||
| DBSHD_DTTM | write_datetime | Date/Time written into SMF buffer | ||
| DBSHD_SSID | ssid | Subsystem ID | ||
| DBSQWH_QWHSLOCN | local_location_name | Local location name | ||
| DBSQWH_QWHSNID | luwid_network_id | LUWID Network ID | ||
| DBSQWH_QWHSLUNM | luwid_luname | LUWID LUNAME | ||
| DBSQWH_QWHSLUUV | luwid_uniquen | LUWID UNIQUEN | ||
| DBSQWH_QWHSLUCC | luwid_commit | LUWID COMMIT | ||
| DBSQWH_QWHSACE | ace_address | ACE address | ||
| DBSQWH_QWHCAID | authorization_id | Authorization ID | ||
| DBSQWH_QWHCCV | correlation_id | Correlation ID | ||
| DBSQWH_QWHCPLAN | plan_name | Plan name | ||
| DBSQWH_QWHCOPID | original_operator_id | Original operator ID | ||
| DBSQWH_QWHCATYP | connection_type | Connection type | ||
| DBSQWH_QWHCCN | connection_name | Connection name | ||
| DBSQWH_QWHCEUID | enduser_id | Enduser USER-ID | ||
| DBSQWH_QWHCEUTX | enduser_transaction | Enduser transaction | ||
| DBSQWH_QWHCEUWN | enduser_workstation | Enduser workstation | ||
| DBSQWH_QWHCTCXT | trusted_context | Trusted context | ||
| DBSQWH_QWHCROLE | role_name | Role name | ||
| DBSQWH_QWHCCTKN | correlation_token | Correlation token | ||
| DBSQWH_QWHDRQNM | requester_location | Requester location | ||
| DBSQWH_QWHDSVNM | server_name_parameter | SRVNAM parameter | ||
| DBSQWH_QWHDPRID | product_id_parameter | Product ID parameter | ||
| DBSQWH_QWHAMEMN | db2_member_name | DB2 member name | ||
| DBSQWH_QWHADSGN | db2_group_name | DB2 group name | ||
| DBSQWH_QWHUCPU | cpu_time_ziip_and_cp | CPU time ZIIP+CP | ||
| DBSQWH_QWHUSE | cpu_time_ziip | CPU time ZIIP | ||
| DBS002B_QBSTPID | buffer_pool_id | Buffer pool ID | ||
| DBS002C_QBGLGG | getpages_gbp_dep_pages | GETPAGES FOR GBP DEP PAGES | ||
| DBS002C_QBGLXD | gbp_reads_under_user_xd | Number of GBP reads under the user task that were necessary due to buffer cross invalidation (XI) in which data was returned | ||
| DBS002C_QBGLXR | gbp_reads_under_user_xr | Number of GBP reads under the user task that were necessary due to buffer XI in which data was not returned from GBP | ||
| DBS002C_QBGLMD | gbp_reads_under_user_md | Number of GBP reads under the user task that were necessary due to the requested page not being found in the buffer pool in which data was returned from GBP | ||
| DBS002C_QBGLMR | gbp_reads_under_user_mr | Number of GBP reads under the user task that were necessary due to the requested page not being found in the buffer pool in which data was not returned | ||
| DBS002C_QBGLSW | changed_pages_written | Number of changed pages written under a user's execution unit (via WAR or WARM) | ||
| DBS002C_QBGLWC | clean_pages_written_wc | Number of clean pages written under a user's execution unit (via WAR or WARM) | ||
| DBS002C_QBGLCT | castout_init_ct | Number of times castout was initiated due to the castout class threshold being detected | ||
| DBS002C_QBGLGT | castout_init_gt | Number of times castout was initiated due to the group buffer pool castout threshold being detected | ||
| DBS002C_QBGLWM | write_and_register_wm | Number of Write and Register Multiple (WARM) requests. Multiple pages written request | ||
| DBS002C_QBGLWS | write_and_register_ws | Number of Write and Register Multiple (WARM) requests. One page written per request | ||
| DBS002C_QBGLEX | explicit_cross_invalidate | Number of explicit cross invalidate | ||
| DBS002C_QBGLAW | changed_pages_written_aw | Number of changed pages written under a system execution unit (via WAR or WARM) | ||
| DBS002C_QBGLRC | pages_castout | Number of pages castout from the Group Buffer Pool to DASD | ||
| DBS002C_QBGLCM | read_castout_multiple | Read For Castout Multiple RFCOM requests. Multiple pages read per request | ||
| DBS002C_QBGLCR | read_castout_rfco | Number of Read For Castout (RFCO) requests. One page read per request | ||
| DBS002C_QBGLWP | pages_written_warm | Number of pages written via WARM | ||
| DBS002C_QBGLWF | gbp_write_requests | Number of GBP write requests that could not complete due to a lack of GBP storage resources | ||
| DBS002C_QBGLOS | ixlcache_read_stgstats | Number of IXLCACHE "read stgstats" requests | ||
| DBS002C_QBGLAC | changed_pages_written_ac | Number of changed pages written under a system execution unit (via WAR or WARM) | ||
| DBS002C_QBGLAX | register_page_list_rpl | Number of of "register page list" (RPL) requests done by Prefetch | ||
| DBS002C_QBGLAY | pages_retrieved | Number of pages retrieved from the group buffer pool as a result of feedback from RPL | ||
| DBS002C_QBGLCK | gbp_checkpoints_triggered | Number of GBP checkpoints triggered by this member | ||
| DBS002C_QBGLUN | ixlcache_unlock_castout | Number of IXLCACHE "unlock castout" requests | ||
| DBS002C_QBGLCC | ixlcache_real_castout_class | Number of IXLCACHE "read castout class" requests | ||
| DBS002C_QBGLCS | ixlcache_read_castout_stats_cs | Number of IXLCACHE "read castout stats" requests | ||
| DBS002C_QBGLDN | ixlcache_delete_name_dn | Number of IXLCACHE "delete name" requests | ||
| DBS002C_QBGLRD | ixlcache_read_dirinfo | Number of IXLCACHE "read dirinfo" requests | ||
| DBS002C_QBGLRG | register_page_requests | Number of "register page" requests | ||
| DBS002C_QBGLDG | unregister_page | Number of "unregister page" requests | ||
| DBS002C_QBGL2F | writes_changed_pages | Number of writes of changed pages to the secondary GBP that failed due to a lack of storage | ||
| DBS002C_QBGL2S | completion_checks_for_writes | Number of completion checks for writes to the secondary GBP that were suspended because the write had not yet completed | ||
| DBS002C_QBGL2D | ixlcache_delete_name_list | Number of IXLCACHE "delete name list" requests to the secondary GBP | ||
| DBS002C_QBGL2R | ixlcache_read_castout_stats_2r | Number of IXLCACHE "read castout stats" requests to the secondary GBP | ||
| DBS002C_QBGL2N | ixlcache_delete_name_2n | Number of IXLCACHE "delete name" requests to the secondary GBP | ||
| DBS002C_QBGLHS | ixlcache_invocations_hs | Number of IXLCACHE invocations for primary GBP | ||
| DBS002C_QBGL2H | ixlcache_invocations_2h | Number of IXLCACHE invocations for seconday GBP | ||
| DBS002C_QBGLP1 | p_lock_requests_1 | Number of page P lock, lock requests for space map pages | ||
| DBS002C_QBGLP2 | p_lock_requests_2 | Number of page P lock, lock requests for data pages | ||
| DBS002C_QBGLP3 | p_lock_requests_3 | Number of page P lock, lock requests for index leaf pages | ||
| DBS002C_QBGLU1 | p_unlock_requests_1 | Number of page P lock, unlock requests | ||
| DBS002C_QBGLS1 | p_lock_suspensions_1 | Number of page P lock, lock suspensions for space map pages | ||
| DBS002C_QBGLS2 | p_lock_suspensions_2 | Number of page P lock, lock suspensions for data pages | ||
| DBS002C_QBGLS3 | p_lock_suspensions_3 | Number of page P lock, lock suspensions for index leaf pages | ||
| DBS002C_QBGLN1 | p_lock_negotiation_1 | Number of page P lock, lock negotations for space map pages | ||
| DBS002C_QBGLN2 | p_lock_negotiation_2 | Number of page P lock, lock negotations for data pages | ||
| DBS002C_QBGLN3 | p_lock_negotiation_3 | Number of page P lock, lock negotations for index leaf pages | ||
| DBS002C_QBGLWA | page_write_around | Number of page in write around |