a. Whenever user session is allocated , dialog work process normally allocates Extended Memory (EM) and once quota of EM is exhausted then its allocates PRIV memory (HEAP).
b. Where as in case of non-dialog work process PRIV memory (HEAP) has been allocated first and then EM.
c. Memory management in SAP is a mechanism to restrict the individual session from consuming whole system memory
Extended memory :
- Dialog Work Process
- Due to frequent content switch is happening , which is possible is EM only.
- EM will be available for dialog till maximum allocated memory is exhausted
- Limit can be set with parameter ztta/roll_extension_dia
2. Non-dialog Work process
- Once PRIV memory is exhausted , EM will allocated.
- If EM is also exhausted for the non-dialog work process, then ABAP dump will be created.
- Limit can be set with parameter ztta/roll_extension_nondia.
Heap Memory:
1. Dialog Work process
- It can only be allocated once EM memory quota is exhausted.
- ABAP dump will be generated once PRIV memory area has been exhausted.
- Limit can be set with parameter abap/heap_area_dia
2. Non- dialog Work Process
- No frequent context switching happens .
- Heap memory is a local memory assigned for the Work process in SAP.
- Quota can be defined with parameter abap/heap_area_nondia.
Exception:
If EM or PRIV memory has been reached to its assigned quote before, total amount of heap memory abap/heap_area_total or Extended memory em/initial_size_MB then also extended memory(non-dialog WP) and PRIV memory (dialog WP) will be allocated accordingly.
