Antwort: Re: explain plan and the real execution plan

Maybe you want to have a look at this article for EXPLAIN PLANS and
EXECUTION PLANS.
Keep in mind, that things like bind peeking won't happen if you generate an
EXPLAIN_PLAN!

http://www.usn-it.de/index.php/2009/02/26/oracle-explain-or-execution-plans-guess-or-reality/


Best regards
--
Mit freundlichem Gruß


Martin Klier
Senior Oracle Database Administrator
------------------------------------------------------------------------------

Klug GmbH integrierte Systeme
Lindenweg 13, D-92552 Teunz
Tel.:  +49 9671/9216-245
Fax.: +49 9671/9216-112
mailto: martin.klier@xxxxxxxxxx
www.klug-is.de
------------------------------------------------------------------------------

Geschäftsführer: Johann Klug, Roman Sorgenfrei
Sitz der Gesellschaft: Teunz, USt-ID-Nr. DE175481608,
HRB Nr. 2037, Amtsgericht Amberg

oracle-l-bounce@xxxxxxxxxxxxx schrieb am 20.11.2009 17:13:59:

> Von:
>
> Yong Huang <yong321@xxxxxxxxx>
>
> An:
>
> oracle-l@xxxxxxxxxxxxx
>
> Datum:
>
> 20.11.2009 17:16
>
> Betreff:
>
> Re: explain plan and the real execution plan
>
> Gesendet von:
>
> oracle-l-bounce@xxxxxxxxxxxxx
>
> In addition, if the queries against this table recently started to
> use columns not used before, the content of col_usage$ will change
> thus affecting the stats related to auto generated historgram.
>
> Yong Huang
>
> Tanel Poder wrote:
>
> > 1)       The optimizer statistics
> >
> > I assume this database has no change – no ddl and dml. Under this
> > situation, I would say the optimizer statistics would remain the same,
> > correct?
>
> Even if you have no DDL and no DML happening, someone may still have
> gathered optimizer statistics on the tables and changed them. Maybe the
last
>
>
>
> --
> http://www.freelists.org/webpage/oracle-l
>
>
>

Other related posts: