topic Re: Oracle and memory windows in Operating System - HP-UX

Oracle and memory windows

Ian Lochray — Thu, 22 May 2003 09:01:19 GMT

I am currently restriced to 32-bit Oracle so I want to use memory windows so I can have 2 x 1GB SGAs. I configures /etc/services.window so that each Oracle system has its own memory window and started the instances.
My application creates a number of servers each of which has its own dedicated Oracle shadow process. My understanding was that I would need to start the applictaion in the same memory windows as the corresponding Oracle system so that the shadow processes could see the Oracle shared memory because the shadow is a child of the application server process and not of Oracle. To test this I started the application without specifying a memory window id. I expected to get a memory access error but the application is running perfectly? How can this be?

Re: Oracle and memory windows

Massimo Bianchi — Thu, 22 May 2003 09:40:28 GMT

Hello,
as far as i know the shadow process is a child of the listener, so if you started the listener in the proper memory windows, you will have no problem.

All communication goes thougt TCP, in any case, the only acccess to direct memory is from the server process.

You may have problem with the BEQ protocol, i think..

Massimo

Re: Oracle and memory windows

Ian Lochray — Thu, 22 May 2003 09:58:46 GMT

I am not running a listener.
I have used memwin_stats to look at an application process and its dedicated shadow. The interesting thing is that the two processes are use different memory windows. I started the Oracle system in user key 8 (kernel key 3) and the application in user key 7 (kernel key 2). memwin_stats shows that the shadow process in in the same memory window as the Oracle system which explains why it all works. I still do not know how it got there.

Re: Oracle and memory windows

Massimo Bianchi — Thu, 22 May 2003 10:11:31 GMT