Re: SQL*Net message to client

From: Jonathan Lewis <jonathan_at_jlcomp.demon.co.uk>
Date: Wed, 23 Nov 2005 19:56:01 -0000
Message-ID: <024101c5f067$f019fd60$6902a8c0@Primary>

John,

I would tend to disagree with that comment. If there are no wait events being recorded, and the process is consuming CPU, then
my usual experience is that something
brutal and inefficient is happening - such as extreme PL/SQL, or massive scanning
and pinning (perhaps through bitmap indexes) with vast amounts of logical I/O. I've seen 'create index' take 30 minutes of CPU with no wait events (after the db file waits for the initial tablescan were over).

I may have come very late to this thread, so someone has probably said already that
wait_time=-1 means less than 1 hundredth of a second for 8i, and less than 50 milliseconds for later versions of 9.

Regards

Jonathan Lewis

http://www.jlcomp.demon.co.uk/faq/ind_faq.html The Co-operative Oracle Users' FAQ

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• Original Message ----- From: "John Kanagaraj" <john.kanagaraj_at_hds.com> To: <stellr_at_cns.vt.edu>; "oracle-l" <oracle-l_at_freelists.org> Sent: Wednesday, November 23, 2005 7:43 PM Subject: RE: SQL*Net message to client

Ray,

>What does WAIT_TIME = -1 indicate?

                                                                             
                    Another

pointer is V$SESSION_WAIT.SEQ# - the value uniquely identifies one episode of the Wait event. This is incremented every time one Wait event completes and another is recorded. You can track the progress of a session from this column.

                                         More importantly, when this value 

does not
increment even though the session consumes CPU, it is a sure indicator that the session is hanging.

Regards,
John Kanagaraj <><
DB Soft Inc
Phone: 408-970-7002 (W)

Co-Author: Oracle Database 10g Insider Solutions http://www.samspublishing.com/title/0672327910

• The opinions and facts contained in this message are entirely mine and do not reflect those of my employer or customers **

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Received on Wed Nov 23 2005 - 13:58:18 CST