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Home -> Community -> Mailing Lists -> Oracle-L -> RE: Huge optimization costs with 9.2
Could it be that the optimizer uses different algorithms since 9.2 value
would default max permutations to 2000 instead of the 80000
OPTIMIZER_MAX_PERMUTATIONS
Parameter type
Integer
Default value
If OPTIMIZER_FEATURES_ENABLE is set to 9.0.0 or higher, then 2000
If OPTIMIZER_FEATURES_ENABLE is set to 8.1.7 or lower, then 80000
Parameter class
Dynamic: ALTER SESSION
Range of values
4 to 80000
David Phillips
Support DBA
Gasper Corporation
dphillips_at_gasper-corp.com
BAARF member #30
-----Original Message-----
Sent: Wednesday, October 01, 2003 1:54 PM
To: Multiple recipients of list ORACLE-L
Yes, they are same. Basically I didn't change any parameter after upgrade.
Guang Mei wrote:
>
> Hi Joan:
>
> Is your "hash_area_size" parameter the same in both situations?
>
> Guang
>
> -----Original Message-----
> Joan Hsieh
> Sent: Wednesday, October 01, 2003 11:55 AM
> To: Multiple recipients of list ORACLE-L
>
> Kirti,
>
> I had upgraded a database from 8.1.7.4 to 9.2.0.4. Before the upgrade,
> performance is good. After upgrade, one query run time from 2 min to
12
> hours. Of course, I re-analyzed all tables and indexes. The explain
plan
> changed from hash join to nested-loop. All the parameters are same. So
I
> have to put optimized_feature_enable=8.1.7 to make run normal as
usual.
> I hate to disable the new feature, but no choose.
>
> Joan
>
> Kirtikumar Deshpande wrote:
> >
> > Were tables/indexes anlayzed after the upgrade?
> >
> > - Kirti
> >
> > --- Jeff Landers <jlanders_at_convergys.com> wrote:
> > > Hello All
> > >
> > > Version & OS:
> > > Upgraded from 9.0.1.4 (Sun Solaris 2.8) to 9.2.0.3.
> > >
> > > Problem:
> > > We've captured the sql text and optimization plans for critical
sql
> > > prior to upgrading to 9.2. After the upgrade we have noticed
> > > that the cost associated with every sql statement is now HUGE
> > > compared to its 9.0.1.4 counterpart. Per the statistics being
captured
> > > via traces,
> > > these statement are noticeably slower per execution.
> > >
> > > Anyone experiencing/experienced the same problem with 9.2?
> > >
> > > Thank you in advance.
> > >
> > >
> >
> > __________________________________
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> > --
> > Please see the official ORACLE-L FAQ: http://www.orafaq.net
> > --
> > Author: Kirtikumar Deshpande
> > INET: kirtikumar_deshpande_at_yahoo.com
> >
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-- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: Joan Hsieh INET: joan.hsieh_at_tufts.edu 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). -- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: Dave Phillips INET: dphillips_at_gasper-corp.com 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).Received on Wed Oct 01 2003 - 13:34:43 CDT
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