Re: How is possible that avg_data_blocks_per_key = 0 even with fresh statistics ?

On Dec 13, 8:57 am, hpuxrac <johnbhur..._at_sbcglobal.net> wrote:
> On Dec 13, 8:59 am, "fitzjarr..._at_cox.net" <fitzjarr..._at_cox.net> wrote:
>
> snip
>
> > Look again, I posted an example proving the contrary to your claim
> > about empty table statistics being retained after the table has been
> > loaded.
>
> I did not make any such claim. You guessed about the possible
> existence of an unproven bug in 9206 on windows. I don't see any
> example proving that.

"The optimizer at times can get confused with tables and indexes that were analyzed when they were empty ( num_rows =0 etc ) but now have data loaded. As best I understand it almost any plan the optimizer might come up relating how to access an empty table may look similar so it can pick the wrong index, use full scan, a strange type of index
access etc. "

You didn't prove that, and it implies empty table statistics being retained or used after a table is loaded. Of course these tables were never empty when statistics were generated, so I can't comprehend why you insist upon beating that same horse over and over without any proof to substantiate your claim.

David Fitzjarrell Received on Thu Dec 13 2007 - 09:15:44 CST