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   comp.databases.oracle      Overblown overpriced overengineered SHIT      2,288 messages   

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   Message 1,213 of 2,288   
   Jim Kennedy to Terry Coccoli   
   Re: Rule Based Optimization   
   01 Apr 04 22:50:36   
   
   From: kennedy-downwithspammersfamily@attbi.net   
      
   "Terry Coccoli"  wrote in message   
   news:Gi_ac.12190390$Of.2034190@news.easynews.com...   
   > We have a Siebel implementation and for one query that was taking a long   
   > time to run I asked a DBA to evaluate the explain plan.  I noticed that   
   > he chose to evaluate the Rule based optimization.  I asked him why and   
   > he said that the Siebel application defaults to Rule based optimization.   
   >   
   > Not that I don't trust him, but I had the impression that Cost based was   
   > the way to go.   
   >   
   > Is it possible to set up a database schema so that it the optimizer   
   > always uses Rule based rather than Cost ?  And if anyone knows Siebel,   
   > is this the actual default ?   
   >   
   >   
   > Thanks.   
   >   
      
   Siebel is rule based.   
   They are about 5 years behind in taking advantage of the database technology   
   that the system runs on.  Yes, cost is the way to go but not with Siebel.   
   They won't support you if you use rule based. (which means you can't do a   
   whole bunch of things)  One thing that you can do to get around this is that   
   if you have a specific query that is better under cost based you can use a   
   stored outline. (get Thomas Kyte's book)   
   Jim   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)   

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