A similar approach is to set optimizer_mode to rule
but analyze everything and then use the
FIRST_ROWS/ALL_ROWS/CHOOSE hint on custom queries...
Still, RBO is a step back into the dark ages...No hash
join, no cpu costing, no function based indexes, no
etc etc etc etc
Cheers
Connor
--- Jared
One relatively effective way to convert an app from
rule to cost is to enable cost in a very
rule-oriented way (namely, you want indexes to be
chosen almost religiously).
You enable cbo but set things like
optimizer_index_cost_adj and optimizer_index_caching
to very index favourable values. I
Connor
You're ass-u-ming that what worked for SAP will work for Siebel. Not a good
assumption. Been there, done it, it does not work ! What you're advocating,
I did similar measures when supporting Ora-Apps when we went from 9.6 to
10.5 (Oracle 7.1.6 RBO to 7.3.2 CBO), what a nightmare that was !
At 01:53 AM 1/31/2003 -0800, Ferenc Mantfeld wrote:
Connor
You're ass-u-ming that what worked for SAP will work for Siebel. Not a
good
assumption. Been there, done it, it does not work ! What you're
advocating,
I did similar measures when supporting Ora-Apps when we went from 9.6
to
10.5 (Oracle
Take a look at the query plan stability features. I believe the original purpose was
to facilitate migration from RBO to CBO. Its been looking good for the small proof of
concepts I have done with it. My overall plan is to capture all plans while in RBO,
turn on usage of Stored Outlines and
Replies below.
Ferenc MantfeldDreaming costs you
nothing. Not dreaming costs you everything.
- Original Message -
Still, some of the queries in Siebel SEEM to run better using CBO.
Ferenc: No doubt this is true, but overall the entire suite comes to a
grinding halt for
On Friday 31 January 2003 07:09, Michael Fontana wrote:
Still, some of the queries in Siebel SEEM to run better using CBO. Is
there any way to mix and match approaches? To use RBO by default, but
perhaps CBO might make sense for certain queries, and perhaps some
AD-HOC?
The problem
I would like to ask a question of this esteemed and knowledgeable
audience about running
SIEBEL applications on Oracle. Siebel insists that their CRM
application will only run with
acceptable performance if rule-based optimization is chosen, yet, as we
all know, there are
documented examples of
Michael:
Would you please post a summary of findings here on the list?
I
too have a Siebel implementation going on, and we are
experiencing performance issues, and have set all the
Siebel-specified initSID.ora parameters.
I am in California, and the database is 'across the pond'
in
, January 31, 2003 4:51
AM
Subject: RE: Oracle, Siebel and
rule-based optimization
Michael:
Would you please post a summary of findings here on the list?
I
too have a Siebel implementation going on, and we are
experiencing performance issues, and have set all
January 30, 2003 12:51 PMTo: Multiple recipients of list
ORACLE-LSubject: RE: Oracle, Siebel and rule-based
optimization
Michael:
Would you please post a summary of findings here on the list?
I
too have a Siebel implementation going on, and we are
experiencing performance issues, an
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