At present, the following restrictions apply to shared objects:
On 32-bit systems, only a limited amount of memory space is available for storing shared objects,
due to the restricted address space. For this reason, shared objects can only be used on 32-bit systems under certain conditions.
When data objects that are referenced using data references are stored, there is also the restriction
that the dynamic type cannot be created at program runtime. A direct reference to data elements and table types belonging to ABAP Dictionary is possible however.
The memory consumption of shared objects in the shared memory cannot be monitored using Memory Inspector.
Memory bottlenecks can occur in the shared objects memory, but they can be dealt with. The associated exception class is CX_SHM_OUT_OF_MEMORY.
There is no memory restriction for logical areas, which generally consist of multiple area instances. There are currently only memory restrictions for individual area instances.
The lifetime of area instances cannot be bound to that of user sessions, ABAP sessions, or transactions. Area instances currently exist as long as the application server instance.