Re: Space used by bind by copy vs space used by bind by reference

[Jon Paris <jon.paris@xxxxxxxxxxxxxx>]

On 26-Jun-09, at 11:08 AM, midrange-l-request@xxxxxxxxxxxx wrote:

> Now, these two modules are bound by copy to virtually ALL our  
> modules. With DSPMOD export and imports I calculate 1491 modules  
> that import from both these modules. Does that mean that the total  
> disk space occupied by  these modules is around 1491 times the total  
> of the two modules, ie 2925318144? I think that says nearly 3Gb.  
> Does that mean I'd gain around 2.8Gb disk space with a service  
> program?
> Or am I just being na?ve as it's quitting time on a Friday?

Yes it does.

But more importantly, it means that when any two of these programs are  
in use at the same time (i.e. both active in the stack) you are using  
twice the memory _per_user_ - if five programs are in use that is five  
times the memory.  Multiply that by your number of active users and  
you'll see that your memory usage (and therefore disk in terms of  
paging storage) are also significantly affected by this practice.

Service programs were invented to avoid the kind of scenario that your  
current practice creates.  You are wasting significant disk space and  
significant memory by binding by copy instead of by reference.  And  
you gain little or nothing.

Jon Paris

www.Partner400.com
www.SystemiDeveloper.com