This parameter allows DBAs and ISVs
to control the maximum amount of application memory that is allocated
by DB2® database agents to service
application requests.
By default, its value is set to AUTOMATIC,
meaning that all application memory requests will be allowed as long
as the total amount of memory allocated by the database partition
is within the instance_memory limits.
- Configuration type
- Database
- 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 [128 - 4 294 967 295]
- Unit of measure
- Pages (4 KB)
- When allocated
- During database activation
- When freed
- During database deactivation
Note: When appl_memory is
set to AUTOMATIC, the initial application memory
allocation at database activation time is minimal, and increases (or
decreases) as needed. The change is applied in memory and the value
of appl_memory does not change on disk as shown
by db2 get db cfg show detail. On next activation,
the value will be recalculated. If appl_memory is
set to a specific value, then the requested amount of memory is allocated
initially during database activation, and the application memory size
does not change. If the initial amount of application memory cannot
be allocated from the operating system, or exceeds the instance_memory limit,
database activation fails with an SQL1084C error (Shared memory segments
cannot be allocated).