Re: CBO irregularity

  • From: Fernando <fernandoluis@xxxxxxx>
  • To: oracle-l@xxxxxxxxxxxxx
  • Date: Mon, 7 Jun 2004 13:26:51 -0700

Honestly, the only problem would be if the Oracle Optimizer behaved the same way in the Dev and the QA machine!!!

from the Manual (Oracle Perf Management Guide), you can do this (in Oracle9 and 10; not sure if 8 has this, but I guess not):

Statistics can be exported and imported from the data dictionary to user-owned tables. This enables you to create multiple versions of statistics for the same schema. It also enables you to copy statistics from one database to another database. You may want to do this to copy the statistics from a production database to a scaled-down test database.

On Jun 7, 2004, at 12:35 PM, Rick Stephenson wrote:

<x-tad-bigger>The CBO has been nothing short of a pain in the butt to me.  Going from Development to QA to a live environment achieves unexpected results.  It seems that you never know what you are going to get when it comes to an execution plan.  The developers run Oracle on their Windows box and the execution path is one way, but when it gets moved to a QA environment it chooses another way.  At least with the RULE base optimizer you know what you are going to get.</x-tad-bigger>

<x-tad-bigger> </x-tad-bigger>

<x-tad-bigger>Sometimes I think I am the only one with this problem.  How do you work this?  Do you always use hints, do you use stored outlines….?</x-tad-bigger>

<x-tad-bigger> </x-tad-bigger>


<x-tad-bigger> </x-tad-bigger>

Rick Stephenson

<x-tad-bigger> </x-tad-bigger>

Other related posts: