Re: Which process spawns a dedicated server process?

From: <ctcgag_at_hotmail.com>
Date: 27 Sep 2003 20:58:13 GMT
Message-ID: <20030927165813.306$g7@newsreader.com>

"Michael J. Moore" <NOhicamelSPAM_at_comcast.net> wrote:
> I posted this on another group but I would still like a more detailed
> answer so I am trying here.
> Here is the conversation as it exists so far ...
>
> ------------------------------
> >>Which process spawns a dedicated server process?
> >>Is it the listener process, or some other Oracle process. Also, on a
> >>Unix
> > > system, when you do "ps -ef" to see your processes, the PPID points
> > > back

 to
> > > a process named "init". Why does the PPID not point to some other
 process
> > > like, for example, the listener, or PMON, or whoever spawned it.

In unixish systems, a process becomes owned by 1 once it's real parent process ends (and maybe also in other situations.) So maybe whatever process spawns the dedicated server either does a double fork, or is short lived.

> > > thanks,
> > > Mike

---

> > The processes are spawned by the OS, repesented by the process called
> > init. Talk to you UNIX admin about how this works.
> >
> > Then my question back to you arises: why do you care?
> >
> > If you are the DBA, then you need to hit the manuals some more.
> > If you are not the DBA, you should not care.
> >
> > (I suspect ayou are not the DBA but you feel to need to control this
> > process somehow. If you have some problem of performance or other,
> > post that and suggestions will come. Looking at process IDs will get
> > you nowhere in understanding the ORACLE operations and architecture.)
> >
> > HTH,
> > ed
> ------------------------------
> Ed, I have hit the manuals resulting in the very need to ask this
> question.
>
> According to OCP 9i Database Fundamentals 1 Exam Guide:
>
> On page 12 it says: "... the listener tells Oracle to generate a new
> dedicated server ..."

"Oracle" is an abstraction, it doesn't exist at the level of detail you are inquiring about.

> yet on page 14 in the questions and answers section
> it says "The listener spawns a new server process."
 

> So, which is it, "listener tell Oracle" or "listener spawns"? Or now you
> have given me a third option "The processes are spawned by the OS".

Everything is done by the OS. And everything is also done by electrons shooting through conductors and semi-conductors.

It depends on the level of abstraction which you are looking at.

>
> The reason I care is because I would like to be able to answer this
> question correctly if it occurs on an exam.

Do you think dissecting the unix system calls is going to help you get the answers correct on exams? Do you think the exam writers write exams from the kernel's perspective?

Xho

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Received on Sat Sep 27 2003 - 15:58:13 CDT