oracle 8.16 ------ NT
A quick one for you all,
i am concered about the number of sessions that are present when i query the V$Session.
Most of the sessions are inactive, or killed, from SCHED. jobs however im concerend that these sessions are in someway affecting performance of the database?
Is this valid? Or am i completley wrong? Any suggestions
Again Many thanks for any help recieved
Inactive sessions don't have any activity.
Killed sessions are either rolling back a transaction or are already dead and waiting to be cleaned up.
The only place this may affect you is if you have a hard limit on the number of sessions that can be connected to your instance.
Inactive sessions, take up the memory, SGA,PGA and it may
hold some transactional locks.
Killed sessions may also hold some transactional and table locks while being rolled back.
Also for killed sessions , if the session being killed was doing a large sort, delete , then it shall take up rollback segment
and SMON would also be busy and take up TS lock.
I had a similar problem to this once.
a lot of killed sessions that would not die.
Check how much cpu PMON is taking, it is its job to release locks and resources held by a killed sesssion.
If it is overworking (I noticed 50%), it may mean there is a problem. Speak to Oracle.
I tried shutdown immediate and the database would not shut down and ended up rebooting the box. Happened to me twice on Oracle 8.1.6 SCO Unix 7.
Once you have eliminated all of the impossible,
whatever remains however improbable,
must be true.
Thanks for the speedy replies, very informative as usual.
what i have done to inactive sessions is
alter system kill session 'SID,Ser#' - however this only changes the status of the sessions
i then tried alter system disconnect 'SID,SER#' immediate
i queried the V$session + still have the same number of sessions?
Is there any way i can completley get rid of them?
Any suggestions / advice is as always appreciatated
Also try to kill them at operating system level
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