Re: process in the gv$session when connecting from TOAD.exe to Oracle

From: John K. Hinsdale <hin_at_alma.com>
Date: 28 Dec 2006 11:04:28 -0800
Message-ID: <1167332668.850123.201570_at_h40g2000cwb.googlegroups.com>

> bill_j_chen_at_yahoo.com wrote:
> > Hi, there,
> >
> > I am trying to understand the PROCESS column in the gv$session
> > ... regarding the 4476:4202 for the TOAD.exe, I don't know what the 4202
> > part is.  After checking the windows processes, I know know the 4476
> > part in 4476:4202 is the process ID for TOAD.exe.

>DA Morgan wrote:

> Windows uses threads not processes is my immediate reaction. But it may > be that someone actually knows the answer so I'll be watching too.

Dan Morgan is exactly right: the number to the right tof the colon is the thread ID (within the process, whose ID appears before the colon).

To verify for yourself, do the following:

• Note the value in column GV_$SESSION.PROCESS, e.g., "<pid>:<tid>"
• Go to your client Windows box, right click on the taskbar and run Task Manager
• Select menu "View ... Select Columns" ... a dialog of checkboxes appears
• Check the box "PID (Process Identifier) and click OK
• Locate the entry for the process of the Oracle client (toad.exe, SQLNav5.exe, etc).
• The value in the Task Manager PID column should agree with what you see in the Oracle system table GV_$SESSION

To prove <tid> is the session ID, you can:
- Download and install

http://download.sysinternals.com/Files/PsTools.zip
- Run the utility "pslist" as follows:

      pslist -d <pid>
  where <pid> is the process ID of your Oracle client.
- You will see a number of thread IDs, one of which matches the ID to
the
  right of the colon in the value in GV_$SESSSION.PROCESS

> Windows uses threads not processes is my immediate reaction.

Actually Windows (at least since Windows 95 and the Win32 model) uses threads AND processes. It used to be Unix used ONLY processes, but now most modern Unixes have intra-process ("user-level") threads built in, though many many applications, including some UNIX Oracle clients,
continue to use the old "one level" process model.

Oracle also seems to put in a lot more of its own "sessions".For your amusement, here
is a link to $GV_SESSION in my demo database, filtered for "internal" sessions:

http://otb.alma.com/otb.fcgi?func=btable&nfilter=1&server=orcl&user=SYS&table=GV_%24SESSION&isview=T&pagesize=100&filtcol1=PROGRAM&filtmode1=C&filtval1=oracle

Hope that helps,

John Hinsdale
hin_at_alma.com Received on Thu Dec 28 2006 - 20:04:28 CET