SAP Memory Area Allocation Sequence

 

SAP Memory Area Allocation Sequence:

SAP Memory area allocation sequence is different for dialog and non-dialog work processes.

SAP Dialog Work Process 

            SAP Dialog work processes are responsible for processing user requests in an ABAP system. The user context is switched frequently, which is only possible in extended memory (EM). For this reason, dialog work processes first allocate a memory area from the EM. The EM is available to work 

processes until the maximum EM quota that can be occupied for dialog work processes is 

reached. This limit is set with profile parameter ztta/roll_extension_dia. 

Once the EM quota is reached, dialog work processes allocate a memory area from the PRIV 

memory (HEAP). If the quota for the PRIV memory (abap/heap_area dia) is reached, the 

running ABAP program is terminated and an ABAP short dump is created. The consumption 

limits of memory (EM or heap) in SAP Memory Management is a protection mechanism in the 

ABAP system that is intended to prevent individual user sessions or programs from using up the entire 

memory. 

Non-Dialog Work Process: 

                   

                       In non-dialog work processes (such as background, update, or spool work processes), the user context is not switched, which is why these work processes are allocated PRIV memory first. 

PRIV memory is available to the work process until the PRIV memory quota that a non-dialog 

work process can allocate for a user context is reached. This quota is defined in the profile 

parameter abap/heap_area_nondia.

If the PRIV memory quota for non-dialog work processes is exceeded, the work. process of this 

type allocates a memory area from the EM. If the EM quota (ztta/roll_extension nondia) is 

exceeded, the running ABAP program is terminated, and a  create short dump.

Reference:

1. help.sap.com 
2. SAP Notes 
3. Linkedin