Something l would try in that position is
create stored outline on ...
your select statement in 8.1.6
Then select from user_outline_hints
to find what hints Oracle had generated
in the fast plan. Then write the same
set of hints into the SQL in 9.2 (or even
export/import the hints) - sometimes
it helps, sometimes it just satisfies the
curiosity.
Regards
Jonathan Lewis
http://www.jlcomp.demon.co.uk
Now available One-day tutorials:
Cost Based Optimisation
Trouble-shooting and Tuning
Indexing Strategies
(see http://www.jlcomp.demon.co.uk/tutorial.html )
____UK_______March 19th
____UK_______April 8th
____UK_______April 22nd
____USA_(FL)_May 2nd
Next dates for the 3-day seminar:
(see http://www.jlcomp.demon.co.uk/seminar.html )
____UK_(Manchester)_May
____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" <[EMAIL PROTECTED]>
Sent: 11 March 2003 14:08
After spending 2 � days trying hints, init parameters, re-writing the
query, a completely useless TAR, etc.
to get a query that runs in < 1 second on 8.1.6.X to go faster than 1
minute on 9.2.0.2
I found a new to 9.2.0.X dynamic init parameter "
optimizer_dynamic_sampling", if I understand it correctly this
parameter forces the optimizer to try harder to get an efficient
execution plan. Check the FM there are some interesting things that
each level causes the optimizer to do.
--
Please see the official ORACLE-L FAQ: http://www.orafaq.net
--
Author: Jonathan Lewis
INET: [EMAIL PROTECTED]
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: [EMAIL PROTECTED] (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).
