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 In Version 9.5, it has been replaced by the appl_memory configuration parameter.
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.
appgroup_mem_sz / app_ctl_heap_sz
appgroup_mem_sz * groupheap_ratio / 100
app_ctl_heap_sz * (100 - groupheap_ratio) / 100
Recommendation: Retain the default value of this parameter unless you are experiencing performance problems.