Re: Memory problems, Oracle 10, Win 2003 (32 bit)

On Jun 15, 1:30 pm, "gym dot scuba dot kennedy at gmail" <kenned..._at_verizon.net> wrote:
> "mike.reid" <chmon..._at_gmail.com> wrote in message
>
> news:5503e537-f8f0-44ad-8fb8-24d4f4924d87_at_y38g2000hsy.googlegroups.com...
>
> >I was hoping to get some assistance from the group....
>
> > I am working with a client who is running into some memory problems
> > with theirOracledatabase.
>
> > Now I am not an expert by a long shot, but the application vendor has
> > told us that their rule of thumb is to always force a pagefile that is
> > 2.5 times the physical memory (so 10gb in this case).
>
> > My understanding on the subject was that becauseOracleis
> > "Opportunistic" with its memory usage that you actually want to pretty
> > much disable the pagefile altogether so thatOracledoes use it.
>
> > Just taking a look at the server seems to tell thatOracleis using
> > about 800mb of physical and 1.7gb total. Is it reasonable in your
> > opinion to run a test and disable the pagefile all together?
>
> > Any help that anyone can give me would be greatly appreciated!
>
> > Mike
>
> I am not sure what the problem is. You sayOracleis using about half the
> memory in the machine. You say you have memory problems. What is the
> memory problem? Very unclear what problem you are having.
>
> On Windows machines if you allocate more memory than you have RAM then you
> will swap some of the memory pages to disk (in the pagefile) If you rarely
> access that memory than things might not be too bad. If you keep accessing
> memory that has been swapped to disk - and force other pages to be written
> to disk - then you can have the machine grind to a halt as it tries to use
> disk as if it were RAM. This is true ofOracleusing the memory or Word or
> any program.
>
> Our crystal balls are in the shop, you need to enlighten us as to what is
> going on more specificaly. My first bit of advice would be to NOT disable
> the pagefile.
> Jim

Thanks for the reply Jim. I agree and I apologize for not being more descriptive.

• 1gb database
• 4gb physical memory, 10gb pagefile
• RAID 5 (shared with OS, DB Logs and DB) Write back cache disabled
• 20 or so users connecting from Terminal Server to DB server, mostly direct calls, some stored procedures

There are some obvious performance improvements to be had with this setup. I am not the application vendor, but am just trying to give a hand. Performance has recently ground to a halt. There are expectations to double the users of the system, the application developers are saying that a new server must be purchased now (which they do actually need a new sever for other reasons, so I'm not too fussed about that). The first thing that we have been told to do is create a pagefile that is 20gb in size (8gb mem on the new server x 2.5).

The question that I have is (and I do not have a lot of experience with Oracle in general):

• Don't you want Oracle to _never_ page to disk? The fact that there is 4gb (physical) memory in the old server and that Oracle was only using 800mb physical, but 1.7gb total (at the time I was on the thing), then is perhaps a course of action to disable the pagefile to force Oracle to use only physical memory? As a test at least?

Again, I apologize for the lack of information. I hope this is better.

Thanks
Mike Received on Wed Jun 18 2008 - 08:55:28 CDT