Re: Better cardinality estimate when dialing optimizer_features_enable back

  • From: Neil Kodner <nkodner@xxxxxxxxx>
  • To: Greg Rahn <greg@xxxxxxxxxxxxxxxxxx>
  • Date: Tue, 24 Nov 2009 14:19:35 -0500

For what its worth, if I just explain plan on select * from letter_bin where
prty_id=12345, I get an incorrect cardinality estimate.  For that reason, I
have not tried isolating other fields.

On Tue, Nov 24, 2009 at 2:09 PM, Greg Rahn <greg@xxxxxxxxxxxxxxxxxx> wrote:

> The next step is to find out which predicate on LETTER_BIN does not
> give the good cardinality estimate.  Evaluate each predicate
> individually first, comparing cardinality, then add one more at a time
> and see if you can track which one is the problem one.  My guess is it
> might be the NOT IN one, but that is just a guess.
> On Tue, Nov 24, 2009 at 10:21 AM, Neil Kodner <nkodner@xxxxxxxxx> wrote:
> > Another data point is if I specify a cardinality hint, I get a desired
> > execution plan (Hash Join instead of NL), and a great response time.
> --
> Regards,
> Greg Rahn

Other related posts: