Re: Tuning SQL in Oracle

Even if you analyzed all your tables and indices, one more issue you might want to consider is to create histograms for the (indexed) columns heavily skewed. They can greatly improve the performance with the CBO sometimes.

Daniel

> On Wed, 30 Jul 2003 18:46:33 +0000, LKBrwn_DBA
> <member30625_at_dbforums.com> wrote:
>
> >
> >Hint:
> >
> >Analyze all tables and indexes.
>
> That's what got me into this. :) My code starting dragging on our
> production database right after a analyze had taken place. Apparently
> we were right under a certain level of data before the analyze was run
> that the new stats took us past. At that point I guess the CBO chose a
> very bad access path.
>
> >http://www.amazon.com/exec/obidos/ASIN/0130123811/qid=1059590327/sr=2-3-
> >/ref=sr_2_3/103-8017330-2186264
>
> Thanks. I just ordered one. This book is a couple of years old though.
> Has the CBO changed much for 9i?
Received on Thu Jul 31 2003 - 15:43:39 CEST