Re: performance issue after upgrade to oracle linux 32 bit.

From: Randolf Geist <>
Date: Sat, 7 Nov 2009 11:19:04 -0800 (PST)
Message-ID: <>

On Nov 7, 10:31 am, "Jonathan Lewis" <> 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


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.


Oracle related stuff blog:

SQLTools++ for Oracle (Open source Oracle GUI for Windows): Received on Sat Nov 07 2009 - 13:19:04 CST

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