Re: Optimizer Hints and Explain Plan

From: joel garry <joel-garry_at_home.com>
Date: Tue, 20 Oct 2009 09:08:01 -0700 (PDT)
Message-ID: <c69c9c79-8747-4c38-9406-e0fd15f729d2_at_e4g2000prn.googlegroups.com>

On Oct 19, 11:03 pm, DeB <debashish.majum..._at_gmail.com> wrote:
> Hi All,
>    I'm using /* no_cpu_costing */ hint in my select statements while
> generating the explain plan. Is it a good idea to use it while
> analyzing the Explain Plan output? Please suggest.
>
> --
> Thanks
> DeB

The presentation and paper linked to here has rules for hints: http://jonathanlewis.wordpress.com/2009/05/09/hints-on-hints/

Note especially the first rule of hints.

Jonathan has also posted a lot about system statistics, here's just one blog entry: http://jonathanlewis.wordpress.com/2007/05/20/system-stats-strategy/

We have no idea what level of expertise you have and what exactly you are trying to accomplish, or even what version you are running, it helps to tell us these things. See http://dbaoracle.net/readme-cdos.htm#subj12

jg

--
_at_home.com is bogus.
"It is true, I've seen many cases such that when mars and jupiter are
well aligned, and solar flares
are low (i'm pretty sure this is important, you know how solar flares
can affect the computing
speed of your cpu and the transfer rates of even solid state drives)
-- end users report better
response time.  Might be the placebo effect, but hey -- who cares.
Just align mars and jupiter and
things are good.

Now, how do I get them to stop moving away, out of alignment, thats
the tricky part.  Need more
coffee to think about that one." - Tom Kyte

Received on Tue Oct 20 2009 - 11:08:01 CDT