Estimating Win32 address-space currently in use by Oracle.exe

Dear List,

I am looking for a good way to measure the "really" reserved memory (the reserved address space = Working Set + pure VirtuallyAllocated memory) for a running 9.2 database on Win32 (something that gives more reliable information than the metalink docs 223730.1, 46001.1, 46053.1). Goal is to prevent Oracle.exe from hitting the 2G / 3G limits on Win32 (AWE/PAE is not possible on our application).

The following query tries to get an estimation without MTS and without adjusting orastack before.

select sum(bytes)/1024/1024 Mb from
(select bytes from v$sgastat

union all
select value bytes from v$sesstat s inner join v$statname n using
(STATISTIC#) where name = 'session pga memory'
union all
select 100*1024*1024 bytes from dual
union all
select count(*)*700*1024 bytes from v$session );

Actually, I'd like to know if I forgot something or if something is wrong with this. Here is a description of the different parts:

1. get the SGA size
2. get the currently total use of PGA memory (containing the "visible" part of the 1MB stack per thread/session?)
3. add 60 to 100 MB for Oracle.exe and DLLs (conservative = 100MB)
4. add 700k (the "unvisible" part of the stack) as VirtuallyAllocated per thread/session

Did I miss something? Are my assumption correct (especially, the one with the stack and it's "visibility"?)

Thanks for your answers in advance
Regards
Peter

--
http://www.freelists.org/webpage/oracle-l