Re: Oh Where Oh Where Is My Redo Coming From

Until I found your comment about 8,000 sessions per day, and the 60 batch jobs in a minute, I was going to say that Dan Fink's idea sounded really good - especially if you extend it to switching on the audit trail (audit_trail=db) and auditing by session, as this leaves a

    log on time,
    log off time
    db block changes (qua logical writes) in the audit trail.

For a more manageable number of connections per day, this might give you a clue about who is doing most data change when.

(Bear in mind, that a user that does a massive data change could leave lots of dirty blocks around, and the next big report might generate a huge amount of redo due to dirty block cleanout. So some of the "redo guilt" could be effectively randomly distributed across innocent victims).

Regards

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

Coming soon one-day tutorials:
Cost Based Optimisation
Trouble-shooting and Tuning
Indexing Strategies
(see http://www.jlcomp.demon.co.uk/tutorial.html )

____UK_______March 19th
____USA_(FL)_May 2nd

Next Seminar dates:
(see http://www.jlcomp.demon.co.uk/seminar.html )

____USA_(CA, TX)_August

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

-----Original Message-----
To: Multiple recipients of list ORACLE-L <ORACLE-L_at_fatcity.com> Date: 21 February 2003 20:06

>As always Jonathan you give me plenty of areas to go looking, thanks
for the
>great advice. One of the problems is cron kicks off various
application
>processes in the line of over 60 per minute (log in, do something,
log out,
>oh and commit between each row of course). That on top of hundreds
of users
>accessing the system and oh 4 or 5 developers working in the same
database
>doing whatever they please. I found one guy the other day had issued
>290,000 commits in a single session using Toad. Argghhhh! You get
the
>idea. I am attempting to bring in a little sanity to the situation
before
>they recommend buying more CPUs!
>
>- Ethan

-- 
Please see the official ORACLE-L FAQ: http://www.orafaq.net
-- 
Author: Jonathan Lewis
  INET: jonathan_at_jlcomp.demon.co.uk

Fat City Network Services    -- 858-538-5051 http://www.fatcity.com
San Diego, California        -- Mailing list and web hosting services
---------------------------------------------------------------------
To REMOVE yourself from this mailing list, send an E-Mail message
to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in
the message BODY, include a line containing: UNSUB ORACLE-L
(or the name of mailing list you want to be removed from).  You may
also send the HELP command for other information (like subscribing).