Hi,
try 'Plan Stability' feature to fix your current RBO
plans. It may be usefull unless your sql is mostly based on
literals
Regards,
Ed
<BLOCKQUOTE dir=ltr
style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
Would suggest testing first with choose. If you were application
was written for RULE it might not run good for CHOOSE. It could run
better, same or worse.
Jeffrey BeckstromDatabase AdministratorGreater Cleveland Regional
Transit Authority1240 W. 6th StreetCleveland, Ohio 44113(216)
781-4204>>> <A
href="">jonas.a.wetterberg_at_manpower.se
10/18/01 9:20:24 AM >>>Hello We upgraded our Oracle
version from 7.3 to Oracle 8.1.7 for a couple ofmonths ago. In Ora 7
environment we used optimizer mode RULE, but now wewould like to change to
CHOOSE, and hopefully gain some performance. As far as I understand
everything, we must collect statistics for thedifferent schemas in the
database to have any advantage of the cost basedoptimizer mode. Our plan
is to do this once a week (is this good enought ortoo often?). According
to Oracle manual, I should use the dbms_stats packageto get statistics. So
a run the following procedure to get
statistics:DBMS_STATS.GATHER_SCHEMA_STATS
(ownname =>
'<schema>',
estimate_percent => 10,
block_sample =>
TRUE,
method_opt => 'FOR ALL COLUMNS
SIZE1',
degree =>
NULL,
granularity => 'DEFAULT',
cascade =>
TRUE);I plan to schedule this and run it once a week. Is this all I
have to do? Itseem too easy. There must some catch somewhere or
??I'm thankfull for any help/Jonas-- Please see the
official ORACLE-L FAQ: <A
href="">
http://www.orafaq.com-- Author: Jonas
A Wetterberg INET: jonas.a.wetterberg_at_manpower.seFat City
Network Services -- (858) 538-5051 FAX: (858)
538-5051San Diego, California --
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Received on Thu Oct 18 2001 - 12:30:30 CDT
