Go to the FreeLists Home Page Home Signup Help Login
 



Browse oracle-l: This Month's ArchiveMain Archive PageRelated postsPrevious by DateNext by Date

RE: CBO - hash join vs nested loops

  • From: "Laimutis Nedzinskas" <lnd@xxxxxxx>
  • To: <oracle-l@xxxxxxxxxxxxx>
  • Date: Mon, 5 Dec 2005 10:31:23 -0000
From: oracle-l-bounce@xxxxxxxxxxxxx
[mailto:oracle-l-bounce@xxxxxxxxxxxxx] On Behalf Of Radoulov, Dimitre

>>1.With apparently correct row source estimate, the CBO chooses not
optimal 
access path.

>I've already read chapter 5 for the clustering factor, congratulations
for 
the great work!

I am interested to here the conclusion: was Oracle CBO correct or not?
I see the following options:

1. CBO was just wrong
2. Oracle was wrong because of inaccurate statistics
3. Oracle was correct.  
4. One interesting option: currently Oracle is correct but in the
future(when more data comes into the system) it can possibly fail. In
theory this case should be handled by regular statistics gathering but
in practice it depends on the answers to 1-3.





--
http://www.freelists.org/webpage/oracle-l


Other related posts:

  • CBO - hash join vs nested loops
  • RE: CBO - hash join vs nested loops
  • Re: CBO - hash join vs nested loops
  • Re: CBO - hash join vs nested loops
  • RE: CBO - hash join vs nested loops
  • Re: CBO - hash join vs nested loops
  • Re: CBO - hash join vs nested loops
  • Re: CBO - hash join vs nested loops
  • Re: CBO - hash join vs nested loops
  • Re: CBO - hash join vs nested loops
  • Re: CBO - hash join vs nested loops
  • RE: CBO - hash join vs nested loops
  • Re: CBO - hash join vs nested loops
  • RE: CBO - hash join vs nested loops
  • Re: CBO - hash join vs nested loops
  • Re: CBO - hash join vs nested loops
  • RE: CBO - hash join vs nested loops
  • Re: CBO - hash join vs nested loops
  • RE: CBO - hash join vs nested loops
  • Re: CBO - hash join vs nested loops




  • [ Home | Signup | Help | Login | Archives | Lists ]

    All trademarks and copyrights within the FreeLists archives are owned by their respective owners.
    Everything else ©2008 Avenir Technologies, LLC.