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DESCRIPTION
SAP Memory Management
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Basics of memory
SAP Roll Area
SAP Extended Memory
SAP Heap memory
SAP Buffer
Agenda
Sap Memory Management
Physical memory and Virtual memory
Basics of Memory
Virtual memory
Paging File
&
Sap Memory Management
Physical memory
/
OS Swap Space
&
Local memory and shared memory
Basics of Memory
Local memoryWorkprocess
Virtual memory
Sap Memory Management
All work processes of one instance
Local memory
Shared Memory
Workprocess
SAP Roll Memory
SAP Roll Memory
� Local SAP Roll area of work process
- The initial part of user context stored
- Each SAP work process can only access its own roll area
�Shared SAP Roll Area
Sap Memory Management
�Shared SAP Roll Area
- Accessible to all of instance work processes
- Buffer to temporary keep user context when a user is assigned to new work process
- Roll in : copying user context from shared roll area to local roll area
- Roll Out : copying user context from local roll area to shared roll area
SAP Roll Memory
Roll buffer (shared memory)Roll area
(local)
Roll file (disk)
Roll area (local)
Work Process1
Work Process2
copy copy
Sap Memory Management
Roll file
Roll (local)
Roll Buffer (shared)
Roll In / Roll Out
ztta/roll_first
ztta/roll_area
SAP Extended Memory
�Extended memory is the heart of the memory system
�Shared memory in which objects, data, internal tables associated with individual users are stored
� All SAP work process can edit stored user context directly
SAP Extended Memory
Sap Memory Management
� All SAP work process can edit stored user context directly
�Each WP has a part of memory reserved in extended memory
� Makes roll process much faster
SAP Extended Memory
Memory allocation for Dialog WP
Extended MemoryHeap
memory
Roll
Area 2
Roll
Area
1
Sap Memory Management
Extended Memory used up Roll
memory used up
WP has entered in PRIV Mode
SAP Heap Memory
SAP Heap Memory
•It is used when Extended and roll memory are full.
•It is allocated and released on demand.
•It is the part of the Local memory
Sap Memory Management
SAP Heap Memory
Sap Memory Management
SAP Buffer/Client Cache
SAP Buffer
• When the object is used frequently, it is moved to the buffer.
• HIT Ratio
• SWAP Rate
Sap Memory Management
• Types of buffer :
1) Repository Buffer
2) Table buffer
3) Prog Buffer
4) SAP GUI Buffer
5) Calendar Buffer
6 ) Export/Import Buffer
SAP Buffer
Sap Memory Management