mon_lockwait - Monitoring lock wait configuration parameter
This parameter controls the generation of lock wait events at the database level for the lock event monitor.
- Configuration type
- Parameter type
- Configurable online
- Default [range]
- NONE [NONE, WITHOUT_HIST, HISTORY, HIST_AND_VALUES]
If you set this parameter to NONE, no lock wait events will be generated unless lock wait event collection is enabled on Db2® Workload objects using the COLLECT LOCK WAIT DATA clause.
If you set the parameter to WITHOUT_HIST, the data about lock events are sent to any active locking event monitor when the lock event occurs. The data collected for the lock wait event will not include a history of activities executed by the application waiting on the lock.
If you set the parameter to HISTORY, the lock wait event will include a history of activities executed by the application waiting on the lock. The history only includes activities executed in the current transaction for the application and will only report the newest activities executed if the maximum sized is reached. The default history size is 250. The history size can be configured using the DB2_MAX_INACT_STMTS registry variable.
If you set the parameter value to HIST_AND_VALUES, activity history collected with the lock timeout event will include the input data values for those activities that have them. These data values will not include LOB data, LONG VARCHAR data, LONG VARGRAPHIC data, structured type data, or XML data. For SQL statements compiled using the REOPT ALWAYS bind option, there will be no REOPT compilation or statement execution data values provided in the event information.
The mon_lockwait parameter value represents a minimum level of collection that is enabled for all Db2 applications. The collection of lock wait events can be enabled for a subset of Db2 applications using the COLLECT LOCK WAIT DATA clause on a Db2 Workload object instead of the mon_lockwait parameter.
When individual Db2 workloads specify a higher level of collection than the configuration parameter, the Db2 workload setting is used instead of the configuration parameter value.You should note that system applications do not run in a workload and so the mon_lockwait parameter is the only way for system applications to collect lock wait data.
This parameter controls the collection of lock wait events at the database level for the lock event monitor. The mon_lockwait configuration parameter is used in conjunction with the mon_lw_thresh configuration parameter. The mon_lockwait parameter determines whether or not a lock wait event will be collected by the lock event monitor when an application waits longer than mon_lw_thresh microseconds for a lock.