tony sheng wrote:
> Hi all,
>
> Can anyone shed some light about the %CPU column in the output of an
> autotrace?
>
> For one of my application queries, I tuned it by adding a few indexes
> - no big deal.
> The cost went down to 95 from 492.
> Here are the top lines from each autotrace:
>
> Before indexes:
> Id Operation Name Rows Bytes Cost
> (%CPU) Time
> 0 SELECT STATEMENT 215 78045 492 (2)
> 00:00:06
>
>
> After indexes:
> Id Operation Name Rows
> Bytes Cost (%CPU) Time
> 0 SELECT STATEMENT 215
> 78045 95 (4) 00:00:02
>
> What I'm wondering about is the signficance about the %CPU column -
> although cost went down, it appears that %CPU went up from 2 to 4.
>
> What exactly does that column mean?
>
> Thanks in advance!
>
In the first case 2% of 492 was the CPU cost
in the second case 4% of 95 if I am lining up
your columns correctly.
--
Daniel A. Morgan
University of Washington
damorgan_at_x.washington.edu
(replace x with u to respond)
Puget Sound Oracle Users Group
www.psoug.org
Received on Sat Apr 21 2007 - 14:48:16 CDT
