RE: Hanging query puzzle

From: Deshpande, Kirti <kirti.deshpande_at_verizon.com>
Date: Wed, 05 Feb 2003 17:28:50 -0800
Message-ID: <F001.00545367.20030205172850@fatcity.com>

Jeff,

If you see the SEQ# field in the v$session_wait view not incrementing, then something else, other than Oracle, is causing a hang up...

On AIX, if you have AIO enabled, try running 'aiostat'. It will show if there are any pending AIO requests. The difficult part would be to relate those pending calls to your session. It is quite likely that a particular AIO server may show waits on I/O, if this hang up is IO related. You can try 'pstat' to find out AIO server processes and associated 'pid' to dig deeper.

If you do not have 'aiostat', ring up IBM Support. It is a nice utility to have, and it is free.

For those on AIX 5L, can you please check if 'aiostat' is available as a standard distribution? I was told by IBM Support that 'aiostat' was going to be available with AIX 5L.

• Kirti

-----Original Message-----
Sent: Wednesday, February 05, 2003 3:20 PM To: Multiple recipients of list ORACLE-L

It looks like your process really is stuck in a way that has nothing to do with the Oracle code directly.

You might look at the CPU usage of your
session and its shadow using an O/S
utility, but I suspect it would show
zero CPU. Perhaps truss (or the AIX
equivalent) might show your process
spinning on whatever call equates to
'has the async read completed yet'.

You could try doing three processstate
dumps with 5 second intervals to see if
the processstate shows any changes
which might give you a hint - but again
I'd GUESS that you'll find nothing happening.

Regards

Jonathan Lewis
http://www.jlcomp.demon.co.uk

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-----Original Message-----
To: Multiple recipients of list ORACLE-L <ORACLE-L_at_fatcity.com> Date: 05 February 2003 21:05

>Still sitting there, while we try to figure out exactly why it's
waiting.
>
>
> SID Username EVENT
>WAIT_TIME STATE SECONDS_IN_WAIT
>----- ---------------- ----------------------------------------------

---

>---------- ------------------- ---------------
> 1 pmon timer
>0 WAITING 79579
> 5 smon timer
>0 WAITING 80
> 12 slave wait
>0 WAITING 199
> 13 slave wait
>0 WAITING 199
> 14 slave wait
>0 WAITING 262
> 15 slave wait
>0 WAITING 199
> 28 NIK db file scattered read
>0 WAITING 20119
>
>-----Original Message-----
>Sent: Wednesday, February 05, 2003 2:58 PM
>To: ORACLE-L_at_fatcity.com
>Cc: Thomas Jeff
>

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-- 
Author: Deshpande, Kirti
  INET: kirti.deshpande_at_verizon.com

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Received on Wed Feb 05 2003 - 19:28:50 CST