Question about abap heap memory.

[Former Member]

Hi Everyone,

Can someone let me know where the heap memory for an abap work process is allocated from, SWAP or Physical Memory?  A reference would be useful as well.  It seems simple but I've found references online to both.

Peter

[Former Member]

Thanks for your answers Roman and Reagan, unfortunately it confirms my confusion.  I have previously looked at the link provided by Reagan and in a nice diagram it shows Heap referencing OS swap.  My own understanding of how things work is in line with what Roman said.

Have I missed something in the link or did SAP just create a bad diagram?

Thanks,

Peter

[Former Member]

Yes, there is a confusing picture.

But in real life, heap memory as well as the extended memory are stored in physical memory. When the physical memory reaches the limit,  operating system moves most unused pages to swap.

[Former Member]

Hi,

Please find the PPT which will explain you in detail and easy about the memory managment .

https://www.google.co.in/url?sa=t&rct=j&q=&esrc=s&source=web&cd=4&cad=rja&ved=0CEcQFjAD&url=http%3A%...

http://help.sap.com/printdocu/core/Print46c/en/data/pdf/BCCSTMM/BCCSTMM.pdf

Please check whether it is helpful or not.

Thanks and Regards,

Vimal

[JPReyes]

Hi Peter,

Heap uses SWAP space(How the OS uses its physical memory to call the data on demand its a different subject), you can clearly read the details in RZ11 for parameters abap/heap*

Have I missed something in the link or did SAP just create a bad diagram?

I wouldn't call it bad, I think theres too much data on it and its not well structured (eerrrmm, ok is bad )

Regards, Juan

[Former Member]

Memory which can be used by OS process can only be in physical memory. Swap is used to store memory pages that are not used in a given time if the system has no free memory. If OS process needs any page that is swapped the OS load this page to physical memory.

Regards,

Roman

[Reagan]

Hello

If you have not seen this link please go through it:

http://help.sap.com/saphelp_nw04s/helpdata/en/02/96279d538111d1891b0000e8322f96/content.htm

Cheers

RB