What is the Maximum Memory a good Program Should Request

here is no thumb rule for maximum memory a good program can consume in the system but based on your experience can you please let me know at least the range ?

I came across with a situation that there is program which is fetching about 2 million records of total size around 190MB. But system could not allocate this much memory so the program aborted. I suggested them to process only 50,000 records at a time which worked fine. But I want to know if my suggestion was good enough. Can't the system with below configuration allocate 190MB for a program. There was no much load on the system at that time.

Our configuration:
SAP 46c on Win 2K
RAM: 4GB
Virtual memory: 8GB.

Do you guys know what are all the things to be done to enable ZERO MEMORY MANAGEMENT in 46C ?

You can get an overall estimate by looking in SM04 and switching on the MB size beside the users so so you will see how much memory the current transactions are using. Take into consideration that there is a big difference between dialog transactions (with several steps) and mass processing or lists. The latter two consume usually a lot more memory.

190 MB is not much, our usercontextes can become as big as 2 GB per user (which is the limit on 32bit platforms) several times a day. This is not uncommon on systems that have a lot of data in them, however, it's impossible to give a general advise here since this is VERY different on what applications you are running, how many systems are connected (BW,
CRM, APO etc.) and so on.

Start with note 88416, there is explained in depth what it is and how it works.

For Windows you also should look in note 129813 which will describe the rebasing process since M$ has the start addresses of their DLLs loaded into the PXA. This is one reason why we switched to a non M$ operating system because after each IE patch (in fact after each patch) you need to check if the new DLLs will fragment your PXA/shared memory.

Note 546361 can also be helpfull. If you have "hangs" in the system read note 530871 which will describe the problem (and finally recommend upgrading to Windows 2003).


What is Zero Administration Memory Management?

The zero administration memory management on Windows requires no manual settings and adapts itself dynamically to the memory requirements of the users. Even hardware changes (for example memory enhancement) are detected and the parameters set correspondingly.

The basis for zero administration memory management on Windows is the dynamically self-extending extended memory. An "infinitely" large memory resource is made available with this method. The extended memory is initially set to the size of the profile parameter PHYS_MEMSIZE ([PM]). If more memory is required by the user, the extended memory extends itself in steps of "[PM] / 2" up to the set limit of the profile parameter em/max_size_MB or until the address space in the Windows pagefile is used up.

By setting the standard value for em/max_size_MB to 20000 MB (100000 MB for 64 bit), it is the size of the Windows pagefile that finally represents the actual limit for the extension of the extended memory. The profile parameter PHYS_MEMSIZE determines how much of the entire main memory is to be used by SAP. The parameter is entered during installation in accordance with the entry. The standard valuefor PHYS_MEMSIZE is the size of the main memory [HS]. Even with zero administration management, the Windows system should be configured in such a way that it keeps the file cache to a minimum size. Therefore, make sure that indicator "Maximize Throughput for Network Application" is activated under 'Control Panel' -> 'Network' -> 'Services' -> 'Server' -> 'Properties'.