RE: Number of threads is twice the number of sessions with 10.2 on Windows platform

Hi,

        Do you have AUTOTRACE enabled in SQL*Plus during these tests?

        SQL*Plus uses another session to collect the statistics when AUTOTRACE is enabled.

        See:
http://asktom.oracle.com/pls/ask/f?p=4950:8:::::F4950_P8_DISPLAYID:5671284058977

Cheers,
Tim

-----Original Message-----
From: oracle-l-bounce_at_freelists.org [mailto:oracle-l-bounce_at_freelists.org] On Behalf Of Giovanni Cuccu
Sent: 24 February 2006 09:45
To: paolo.desalvo_at_gmail.com
Cc: Oracle-L
Subject: Re: Number of threads is twice the number of sessions with 10.2 on Windows platform

Hi all,

    more little tests on the issue. I knew that enabling the parameter sqlnet.expire_time (i.e. setting it to a value more than 0) has this side effect, i.e. it creates another thread (a watchdog thread) only for monitoring the real one. I just tested this on a 9.2 on winzozz. Now my opinion is that in 10.2 there is the watchdog thread even if sqlnet.expire time is 0. I enabled the sqlnet trace with expire_time=0 and the log clearly reports DCD disabled.I enalbed DCD with expire_time=1, the sqlnet log reports the dcd enabled, but the number of threads created is "still" two.
Now these tests are not enough to build a theory on what's happening but my guess is that starting from 10.X there is an watchdog thread with monitors the real session. Time permitting I will do some others test to verify if dead session detecting is changed from 9.2. to 10.2 and how. Hope it helps,

   Giovanni

On 2/23/06, Paolo Desalvo <paolo.desalvo_at_gmail.com> wrote:
> Hi all.
>
> I have noticed too many threads in the Task Manager related to the
> ORACLE.EXE process for 10.2.
>
> So I run a simple testcase program on a test server with no activity
> and I fired 10 SQLPLUS connections to the 10.2 database; the number of
> threads increased from 31 to 51, so 2 threads for each session
> connected to the database.
>
> Then I run the same program on the same test server directing the
> connections to a 9.2 database; the number of threads increased from 12
> to 22, so 1 thread for each session, as expected.
>
> Is there anybody with the same problem?
>
> Thanks
> Paolo

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