This parameter determines the amount of the memory, in
pages, to allocate for database system monitor data. Memory is allocated
from the monitor heap when you perform database monitoring activities
such as taking a snapshot, turning on a monitor switch, resetting
a monitor, or activating an event monitor.
With Version 9.5, this database configuration parameter
has a default value of AUTOMATIC, meaning that the
monitor heap can increase as needed until the instance_memory limit
is reached.
- Configuration type
- Database manager
- Applies to
-
- Database server with local and remote clients
- Database server with local clients
- Partitioned database server with local and remote clients
- Parameter type
- Configurable online
- Default [range]
- Automatic [0 - 60 000]
- Unit of measure
- Pages (4 KB)
- When allocated
- When the database manager is started with the db2start command
- When freed
- When the database manager is stopped with the db2stop command
A value of zero prevents the database manager from
collecting database system monitor data.
Recommendation: The
amount of memory required for monitoring activity depends on the number
of monitoring applications (applications taking snapshots or event
monitors), which switches are set, and the level of database activity.
If set to AUTOMATIC, if the configured memory in this
heap runs out and no more unreserved memory is available in the instance
shared memory region, one of the following will occur:
- When the first application connects to the database for which
this event monitor is defined, an error message is written to the
administration notification log.
- If an event monitor being started dynamically using the SET
EVENT MONITOR statement fails, an error code is returned
to your application.
- If a monitor command or API subroutine fails, an error code is
returned to your application.
If a numerical value (not AUTOMATIC) is set,
no more than the configured amount of memory is available for monitoring
(regardless of free instance memory).