Agree Operating system decides where the extended memory resides...
When an instance startup a part of memory allocated to instance called as shared memory.
Which consist of all the buffers, roll area, extended memory etc.
Whenever the user process any tcode work process alloacate to user. Data processed by the work process is stored in two memory areas
1. Roll Area: In which user context data is stored like authorizations, internal table etc.
2. Paging Area : Stores the application program data more precisely abap command including Extract, Import to memory, Export to memory call transaction etc.
Paging Area= Page Buffer + Page File
Page buffer is a part of shared memory where as Page File resides at physical level. Data swap as per the requirement in Page Buffer and Page File.
If data processing demands more memory, than the concept of Heap came into picture which is also called as local memory.
Memory Parameters are there to defines the values for all of them. If memory utilization for individual work process reached the max. limit of heap than work process stuck in PRIV mode with all the allocated memory.
Hope this helps to build a general idea about the memory allocation.
your answer is really worthy....one more question is in ST02 there is one In memory and on disk two parts of SAP memory..whats that? and also there are RED swap ...whats its indicates?
"In memory" is a part used from shared memory and "on disk" are role files, page files stored at physical level. None zero swap values are highlighted with red.
The way you explain is too good..Can you please tell me the concept of overall sap connections with memory and other stuff.. I am trying to connect things but in doubt.. please brief in short
I have already referred that link.but its not get cleared where exactly extended memory resides?
I want to know SAP memory architecture.I have referred all its documents but still having some doubt....when I found that any user found dump on system for memory exhaust, there is still free memory in RAM ...what is the reason?
You must be a registered user to add a comment. If you've already registered, sign in. Otherwise, register and sign in.