Re: performance issue after upgrade to oracle 11.2.0.1 linux 32 bit.
Date: Sat, 7 Nov 2009 11:19:04 -0800 (PST)
Message-ID: <4b391076-6085-4acc-9065-e24f07f24002_at_v25g2000yqk.googlegroups.com>
On Nov 7, 10:31 am, "Jonathan Lewis" <jonat..._at_jlcomp.demon.co.uk> wrote:
> I've had a quick read through the posts I can see at the moment.
> The critical issue is (as Charles and Randolf have pointed out)
> the use of first_rows_100, combined with Randolf's observation
> that the expected result set is 40 million rows.
>
> >> First K Rows: K = 100.00, N = 40640900.00
> >> First K Rows: Setup end
Jonathan,
that was one of my first thoughts as well but I was a bit reluctant to draw this conclusion because - probably due to the "dynamic proration" feature - there are more ALL_ROWS plans further down the trace file, leading e.g. to this one:
First K Rows: K = 100.00, N = 73255.00
which makes the sort operation very likely look much cheaper, so I wasn't entirely sure that this is the root cause of the problem, given that we obviously don't see the complete trace file.
Regards,
Randolf
Oracle related stuff blog:
http://oracle-randolf.blogspot.com/
SQLTools++ for Oracle (Open source Oracle GUI for Windows):
http://www.sqltools-plusplus.org:7676/
http://sourceforge.net/projects/sqlt-pp/
Received on Sat Nov 07 2009 - 13:19:04 CST