Re: Create common user in all PDB's

From: John Piwowar <jpiwowar_at_gmail.com>
Date: Fri, 4 Feb 2022 09:59:45 -0800
Message-ID: <CAJgcjABdjO+DcL_z2KVQ795uYSHLBcQfT8WOgrBLo7v7Ot3xCg_at_mail.gmail.com>



Starting with a disclaimer: I'm an Oracle employee, but neither in a support org nor in a role that relates directly to the internals of technologies discussed in this thread. Opinions are my own, I don't represent Oracle here, etc, etc. This is basically what I would've said in my consulting days, anyway:

First, I strongly recommend logging an SR for this. A huge number of PDBs in a single CDB is *unusual, *but it's not unique*. *You certainly appear to be bumping up against a scale issue with the patch process, and if so you're unlikely to be the only customer to do so. There may be a solution already, or if it's actively being worked on, you can at least be added to any existing bugs to be notified of a solution.

Second, as you've suggested (and the ORA-12805 errors reinforce), there are a lot of data dictionary operations that are parallelized when executed from the CDB$ROOT level; you *might* be running into that here. You can also probably see the PQ operations heavily represented in AWR/ASH reports. You may get better results by throttling the PQ settings in your environment during the patch process...where "better" is "At least the server doesn't fall down." :) That's only a guess...I don't have that kind of environment available to conduct experiments.

Regards,

John P.

On Fri, Feb 4, 2022 at 7:23 AM jacques kostic <jacques.kostic_at_gmail.com> wrote:

> Hi there,
>
> Here is a nice one:
>
> Customer is under Exadata CS, 2 nodes with 10 cores in each node.
> He has a CDB with more than 2'500 PDB's.
>
> He needs to patch the Exadata CS tooling and during the patching a common
> user is created into all PDB's.
> At this point, the CPU goes bananas and the process stops with ORA-12805
> (os related)
> The system is just overloaded!
>
> Am I wrong to say that this Create common user goes in // on all PDB when
> add container=all?
>
> We could split the process and proceed by chunks but of course we cannot
> touch the patching scripts...
>
> Any way to avoid this // create common user processing?
>
> Cheers
> jko
>
>

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Received on Fri Feb 04 2022 - 18:59:45 CET

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