DB2 10.5 for Linux, UNIX, and Windows

appgroup_mem_sz - Maximum size of application group memory set configuration parameter

This parameter has been deprecated since Version 9.5, but is still being used by pre-Version 9.5 data servers and clients. Any value specified for this configuration parameter will be ignored by the database manager in DB2® Version 9.5 or later releases. In Version 9.5, it has been replaced by the appl_memory configuration parameter.

Note: The following information applies only to pre-Version 9.5 data servers and clients.

This parameter determines the size of the application group shared memory segment.

Configuration type

Database

Parameter type

Configurable

Default [range]

UNIX Database server with local clients (other than 32-bit HP-UX)

20 000 [1 - 1 000 000 ]

32-bit HP-UX

Database server with local clients
Database server with local and remote clients
Partitioned database server with local and remote clients

10 000 [1 - 1 000 000 ]

Windows Database server with local clients

10 000 [1 - 1 000 000 ]

Database server with local and remote clients (other than 32-bit HP-UX)

30 000 [1 - 1 000 000 ]

Partitioned database server with local and remote clients (other than 32-bit HP-UX)

40 000 [1 - 1 000 000 ]

Unit of measure

Pages (4 KB)

Information that needs to be shared between agents working on the same application is stored in the application group shared memory segment.

In a partitioned database, or in a non-partitioned database with intrapartition parallelism enabled or concentrator enabled, multiple applications share one application group. One application group shared memory segment is allocated for the application group. Within the application group shared memory segment, each application will have its own application control heap, and all applications will share one application group shared heap.

The number of applications in one application group is calculated by:

appgroup_mem_sz / app_ctl_heap_sz

The application group shared heap size is calculated by:

appgroup_mem_sz * groupheap_ratio / 100

The size of each application control heap is calculated by:

app_ctl_heap_sz * (100 - groupheap_ratio) / 100

Recommendation: Retain the default value of this parameter unless you are experiencing performance problems.