ACUCOBOL-GT manages external data items by allocating them in "pools". The minimum size of each pool is set by the EXTERNAL-SIZE configuration option.
When a new external data item is needed, it is allocated from an existing pool. If it does not fit in any of the allocated pools, a new pool is allocated. The size of this pool is the same as the size of the data item, but never smaller than the value specified by the EXTERNAL-SIZE option. This reduces memory fragmentation. There are 16 pools available altogether.
Because external data items remain allocated after programs are canceled, it is best to allocate the external data items together so they do not break up the memory space. The default value for EXTERNAL-SIZE is "4096".