Re: index selectivity when histograms presents on the column

The explanation is found in Jonathan Lewis' CBO book:

http://www.amazon.com/gp/product/1590596366

There is a rather extensive chapter on histgrams, and it does cover selectivity.

Jared

On 3/21/06, The Human Fly <sjaffarhussain_at_gmail.com> wrote:
>
> List,
>
> Can anyone tell me the index selectivity formula for a column when
> there are histograms on the column.
> I know that the index selectivity without histograms is =
> num_distinct/num_rows and also know that table selectivity uses
> density to calculate the selectivty when there are histograms placed
> on the column.
>
> Thanks,
> --
> Best Regards,
> Syed Jaffar Hussain
> 8i,9i & 10g, OCP DBA
> Banque Saudi Fransi,
> Saudi Arabia
> http://jaffardba.blogspot.com/
>
> ----------------------------------------------------------------------------------
> "Winners don't do different things. They do things differently."
> --
> http://www.freelists.org/webpage/oracle-l
>
>
>

--
Jared Still
Certifiable Oracle DBA and Part Time Perl Evangelist

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