RE: Migration from 8i to 11g
Date: Thu, 8 Mar 2012 00:20:29 +0000
Message-ID: <BAA6E28B6241F046AED1E62D8697516C56302578_at_COPDCEXMB08.cable.comcast.com>
Agreed, definitely check your performance and queries. We heavily used RBO (lots of +RULE) hints; however, we were fortunate find very few queries that didn't perform well after migrating from 8i to 11.2, many of those were simply tunes using the SQL Performance analyzer (and were moved to prod from test - using SQL Plan baselines - http://tinky2jed.files.wordpress.com/2011/04/making-plans-with-11g-and-not-leaving-them-behind.pdf )
-----Original Message-----
From: oracle-l-bounce_at_freelists.org [mailto:oracle-l-bounce_at_freelists.org] On Behalf Of Rodd Holman
Sent: Wednesday, March 07, 2012 11:55 AM
To: 'oracle-l_at_freelists.org' (oracle-l_at_freelists.org)
Subject: Re: Migration from 8i to 11g
I second this. We migrated from 9i to 10g in 2007. Oracle had significantly changed/re-written the CBO. Things that used to fly, crawled. There is definitely a post migration need to stress test your queries, and user adhoc queries if they are allowed. Rodd Holman
On Wed, Mar 7, 2012 at 12:33 PM, Dennis Williams < oracledba.williams_at_gmail.com> wrote:
> David, (resending without quoting prior posts) Does your applications
> on 8i use RBO or CBO? Even if it uses CBO, the query execution plans
> may differ in 11g. When we migrated some critical apps from 8i to 10g
> a few years ago (a direct upgrade) that was the main source of issues.
>
> Dennis Williams
>
>
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-- http://www.freelists.org/webpage/oracle-l -- http://www.freelists.org/webpage/oracle-lReceived on Wed Mar 07 2012 - 18:20:29 CST