Re: Which process spawns a dedicated server process?

From: Yong Huang <yong321_at_yahoo.com>
Date: 27 Sep 2003 21:12:25 -0700
Message-ID: <b3cb12d6.0309272012.5df0fec6@posting.google.com>

"Michael J. Moore" <NOhicamelSPAM_at_comcast.net> wrote in message news:<rxldb.166107$mp.90993_at_rwcrnsc51.ops.asp.att.net>...

> ------------------------------

> >>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.
> > > 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 ..." 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".

Hi, Michael,

Your question is quite legitimate. On UNIX, when you connect to the database in dedicated configuration through SQL*Net, the listener spawns a child process, immediately forks, the parent exits, and the child exec's $ORACLE_HOME/bin/oracle. The server process thus created (or called shadow process as if it were a shadow of your client process) behaves like a UNIX daemon. The reason a server process has a parent pid of 1 is that it's a child of a parent who exited.

Yong Huang Received on Sat Sep 27 2003 - 23:12:25 CDT