Data generated by change history event monitors
Change history event monitors capture information about activities that might impact the performance, behavior, and stability of databases and database management systems. The output from a change history event monitor is written to logical data groups, where each logical data group has an associated event monitor table.
A change-related action can generate one or more events in the
change history event monitor. For example, a database configuration
update generates a single event, while the execution of the REORG
utility generates two events that mark the beginning and end of the
REORG operation. There is a one-to-many mapping between an event and
a logical data group. An event can write information to more than
one logical data group and can write more than one entry (row) to
the table associated with a given logical data group. Each change-related
event is uniquely identified by the following three key fields:
- Event timestamp
- The time that the event occurred.
- Event ID
- A numeric token that ensures uniqueness in cases where the event timestamp is common.
- Member
- The database manager process where the event occurred.
All logical groups contain these three fields and all records or rows corresponding to the same event contain the same values for these fields. These common values facilitate the joining of information across different logical data groups. Utility operations and configuration parameter updates on different members are captured as different events and result in different values for these key fields.
The change history event monitor only supports the TABLE target for event monitor logical data groups. The change history event monitor does not support UNFORMATTED EVENT TABLE, FILE, and PIPE targets.
The following table contains a list of the logical data groups
and associated tables used by the change history event monitor. The
default table name for each logical data group is derived by concatenating
the name of the logical data group used to populate the table with
the name given to the event monitor when it was created using the
CREATE EVENT MONITOR statement. The table names shown are the default
table names when a name is not specified as part of the CREATE EVENT
MONITOR statement.
| Default table name | Logical data group |
|---|---|
| CHANGESUMMARY_evmon-name | CHANGESUMMARY |
| DBDBMCFG_evmon-name | DBDBMCFG |
| REGVAR_evmon-name | REGVAR |
| DDLSTMTEXEC_evmon-name | DDLSTMTEXEC |
| TXNCOMPLETION_evmon-name | TXNCOMPLETION |
| EVMONSTART_evmon-name | EVMONSTART |
| UTILSTART_evmon-name | UTILSTART |
| UTILLOCATION_evmon-name | UTILLOCATION |
| UTILSTOP_evmon-name | UTILSTOP |
| UTILPHASE_evmon-name | UTILPHASE |
The change history event monitor can capture a wide range of events. Not all events are of interest to all users. You can control which event types are captured by the change history event monitor by using the WHERE EVENT IN clause in the CREATE EVENT MONITOR statement when you create the event monitor.
The following table shows the actions on the database server that
generate events available for capture by the change history event
monitor. It also indicates which control options specified in the
WHERE EVENT IN clause results in the capture of these events and which
logical data groups are populated when the event is generated.
| Action | Event type | WHERE EVENT IN clause | Logical data group | Details |
|---|---|---|---|---|
| Changing a database configuration parameter | DBCFG | CHANGESUMMARY DBDBMCFG |
1 record written to CHANGESUMMARY 1 record written to DBDBMCFG for each changed parameter |
|
| Capturing all database configuration parameter values at event monitor startup if a database configuration parameter was changed while the event monitor was inactive | DBCFGVALUES | CHANGESUMMARY DBDBMCFG |
1 record written to CHANGESUMMARY 1 record written to DBDBMCFG for each parameter |
|
| Changing a database manager configuration parameter | DBMCFG | CHANGESUMMARY DBDBMCFG |
1 record written to CHANGESUMMARY 1 record written to DBDBMCFG for each changed parameter |
|
| Capturing all database manager configuration parameter values at event monitor startup if a database manager configuration parameter was changed while the event monitor was inactive | DBMCFGVALUES | CHANGESUMMARY DBDBMCFG |
1 record written to CHANGESUMMARY 1 record written to DBDBMCFG for each parameter |
|
| Changing a registry variable. Only immediate updates (registry variable changes that use the -immediate flag on the db2set command) generate events. | REGVAR | CHANGESUMMARY REGVAR |
1 record written to CHANGESUMMARY 1 record written to REGVAR for each changed variable. Only registry variables that are set explicitly are captured. No records are written for variables that are implicitly set through an aggregate registry variable. |
|
| Capturing registry variable values at event monitor startup | REGVARVALUES | CHANGESUMMARY REGVAR |
1 record written to CHANGESUMMARY 1 record written to REGVAR for each explicitly set variable |
|
| Executing a DDL statement successfully | DDLSTMTEXEC | CHANGESUMMARY DDLSTMTEXEC |
1 record written to CHANGESUMMARY 1 record written to DDLSTMTEXEC |
|
| Commit or rollback of a transaction containing a successfully executed DDL statement or the rollback to a savepoint containing a successfully executed DDL statement | TXNCOMPLETION | CHANGESUMMARY TXNCOMPLETION |
1 record written to CHANGESUMMARY 1 record written to TXNCOMPLETION |
|
| Starting or stopping the event monitor | EVMONSTART | CHANGESUMMARY EVMONSTART |
1 record written to CHANGESUMMARY 1 record written to EVMONSTART |
|
| Starting utility execution or resuming execution after being paused. This event is only generated on the coordinator member | UTILSTART | CHANGESUMMARY UTILSTART UTILLOCATION |
1 record written to CHANGESUMMARY 1 record written to UTILSTART 0 or more records written to UTILLOCATION; 1 record for each file associated with a utility start. |
|
| Completing utility execution or pausing execution. This event is only generated on the coordinator member | UTILSTOP | CHANGESUMMARY UTILSTOP |
1 record written to CHANGESUMMARY 1 record written to UTILSTOP |
|
| Processing of a utility starts on a member. This event is only generated in a multi-member environment | UTILSTARTPROC | CHANGESUMMARY UTILSTART |
1 record written to CHANGESUMMARY 1 record written to UTILSTART |
|
| Processing of a utility stops on a member. This event is only generated in a multi-member environment | UTILSTOPPROC | CHANGESUMMARY UTILSTOP |
1 record written to CHANGESUMMARY 1 record written to UTILSTOP |
|
| Starting the execution of a specific processing phase of a utility on a member | UTILPHASESTART | CHANGESUMMARY UTILPHASE |
1 record written to CHANGESUMMARY 1 record written to UTILPHASE |
|
| Stopping the execution of a specific processing phase of a utility on a member | UTILPHASESTOP | CHANGESUMMARY UTILPHASE |
1 record written to CHANGESUMMARY 1 record written to UTILPHASE |