Re: Dataware house DB's Cross Platfarm migration

From: George Leonard - Business Connexion <George.Leonard_at_bcx.co.za>
Date: Tue, 9 Sep 2014 04:50:04 +0000
Message-ID: <9D604510-5B14-4C85-911C-59DBC435D236_at_bcx.co.za>



Hi there,

You can potentially look t outlines, to "pin" the execution plans, but also remember what you might end doing is pin a execution plan that works now, but might actually end with a even better execution plan on the target platform.

As long as you're just moving platforms you should not really get a change, you're moving the datafiles as they are.

if you updated the system stats and told the kernel/optimiser about a different cost to IO and CPU then ye, that might change the plans, but then again, don't you potentially want this.

I'd record what the execution plans look like atm, hen migrate, where it went worse go and implement changes to revert to old plans, but let the system first see if it can't do it better.

Yours Sincerely



George Leonard
Oracle Engineered System Specialist

Mobile: +27.82 655 2466
eMail: george.leonard_at_bcx.co.za<mailto:george.leonard_at_oracle.com> Web: http://www.bcx.co.za<mailto:george.leonard_at_oracle.com>

[cid:6EA60917-E50D-422D-BF1F-E8C59EADC861]

On 04 Sep 2014, at 5:43 AM, Seth Miller <sethmiller.sm_at_gmail.com<mailto:sethmiller.sm_at_gmail.com>> wrote:

Bala,

Real Application Testing (RAT)<http://docs.oracle.com/cd/E11882_01/server.112/e41481/rat_intro.htm#RATUG101> was designed to address these exact questions. The two tools in this group that are relevant to your questions are SQL Performance Analyzer (SPA) and Database Replay.

Seth Miller

On Thu, Aug 7, 2014 at 8:52 PM, Bala Krishna <krishna000_at_gmail.com<mailto:krishna000_at_gmail.com>> wrote: Hi Team,

We've a plan to migrate Dataware house Database's from Aix to Linux with Transportable Tablespace as an option.

Bascally i'm looking forward to measure performance before and after migration and its implications.

Requesting you to please answer the below questions , i appreciate if there are any pointers to some links etc.

  1. Since the change in system stats how do we make sure that our execution plans will not change majorly ? and its performance slowness.
  2. If there are any executions plans are really performing bad after migrating , what would be the best options that you suggest to compare before and after migrate plans and suggest the best solutions to resolve those issues ?
  3. Implementing baselines is that a good idea ?
  4. Exporting and importing stats will help to keep best optimum performance?

Appreciate your response.

Regards
Bala



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Received on Tue Sep 09 2014 - 06:50:04 CEST

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