Re: Frequent logswitches

From: Jack van Zanen <jack_at_vanzanen.com>
Date: Thu, 23 May 2019 07:55:09 +1000
Message-ID: <CAFeFPA-Bsq3TwBUr2b9efKuLvCwVfi4TNXB1ynddQiOfk50p7A_at_mail.gmail.com>

Hi

I think I have identified some processes that are responsible for a lot of block changes and based on that I think I can get a rough estimate which PDB is most likely the culprit...

Is it normal to have the DBW and LMS processes to have the largest redo size?
(I guess it is)

Jack van Zanen

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On Wed, May 22, 2019 at 10:57 PM Mark W. Farnham <mwf_at_rsiz.com> wrote:

> The most pedestrian way is to set up a second container database and move
> one pdb back and forth at a time running it in the other container long
> enough to determine how much redo it generates.
>
>
>
> This will double the number of non-PDB processes (that is the container
> infrastructure) whenever both container are running, so you may or may not
> have sufficient headroom on memory and so forth.
>
>
>
> The answer, though, should be quite precise.
>
>
>
> There are probably other ways to make this measurement that do not involve
> re-plugging.
>
>
>
> mwf
>
>
>
> *From:* oracle-l-bounce_at_freelists.org [mailto:
> oracle-l-bounce_at_freelists.org] *On Behalf Of *Jack van Zanen
> *Sent:* Wednesday, May 22, 2019 12:09 AM
> *To:* oracle-l_at_freelists.org
> *Subject:* Frequent logswitches
>
>
>
> Hi All
>
>
>
>
>
> Oracle 12.2.0.1 Multitennant database RAC
>
>
>
> Is there a way to figure out which PDB is mostly responsible for the
> generation of REDO?
>
>
>
> On that same topic:
>
>
>
> Is it normal to have the DBW and LMS processes to have the largest redo
> size?
>
> (I guess it is)
>
>
>
> Regards
>
>
>
>
>
>
>
>
> Jack van Zanen
>
>
>
>
> -------------------------
> This e-mail and any attachments may contain confidential material for the
> sole use of the intended recipient. If you are not the intended recipient,
> please be aware that any disclosure, copying, distribution or use of this
> e-mail or any attachment is prohibited. If you have received this e-mail in
> error, please contact the sender and delete all copies.
> Thank you for your cooperation
>

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Received on Wed May 22 2019 - 23:55:09 CEST