PDB

Recent News about Pluggable Databases – Oracle Multitenant

Three recent lessons about PDBs in the Oracle Single/Multitenant space you should be aware of.

And thanks to my teammates and the Multitenant PMs for bringing this into our radar.

Unplug/plug – don’t forget to DROP your PDB

I’ve had to add a single line to my previous blog post about the upgrade solution Unplug/Plug/Upgrade for PDBs:
https://mikedietrichde.com/2014/08/05/upgrade-pdbs-one-at-a-time-unplugplug/

Unplug Plug Upgrade PDB Oracle Mutitenant

You’ll have to DROP your PDB after you have unplugged it as otherwise the information will stay in the CDB’s dictionary where you have unplugged it from (a) forever and (b) during an subsequent upgrade of the entire source CDB. But the …

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Create Container Databases (CDB) with less options – it’s now supported in Oracle 12.1.0.2

When Oracle Multitenant was launched Roy and I amongst many other people always mentioned that the requirement of having all options in a Container Database (CDB$ROOT), and therefore also for the PDB$SEED with the immediate result that all PDBs provisioned from the PDB$SEED will have all options as well, will hinder customer adoption significantly. But this has been changed now. You can create Container Databases (CDB) with less options – it’s now supported in Oracle 12.1.0.2.

Create Container Databases (CDB) with less options – it’s now supported in Oracle 12.1.0.2

Almost all customers I have talked to in the …

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Applying a PSU or BP to a Single-/Multitenant Environment

I have already explained in broad details a while ago how to:

But one may miss the steps for applying a PSU (Patch Set Update) or BP (Bundled Patch) to a Single-/Multitenant Environment.

At first everything will work just the same if you choose the Everything-at-Once strategy as datapatch will adjust all the required things regardless of being executed in a stand-alone or a singe/Multitenant environment.

But what happens if you apply a …

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Automatic Maintenance Jobs in every PDB?
New SPM Evolve Advisor Task in Oracle 12.1.0.2

A customer checking out our slides from the OTN Tour in August 2014 asked me a finicky question the other day:

“According to the documentation the Automatic SQL Tuning Advisor maintenance task gets executed only within the CDB$ROOT, but not within each PDB – but the slides are not clear here. So what is the truth?”

Ok, that’s good question. In my understanding all tasks will get executed within each PDB – that’s why we recommend (based on experience) to break up the default maintenance windows when using Oracle Multitenant. Otherwise all PDBs will have the same maintenance windows, and …

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Upgrade PDBs – Everything At Once (Full CDB Upgrade)

As referred to it before there are two techniques to upgrade an Oracle Multitenant environment:

In this post I will explain the method of “Everything At Once” and describe all the steps. The benefit of this approach is simplicity and ease of maintenance. In an upgrade workshop in Melbourne earlier this year a DBA from Germany came by in one of the breaks explaining that he takes care on over 100 developer databases – and it would ease his life a lot if he could …

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Upgrade PDBs – One at a Time via unplug/plug/upgrade

Basically there are two techniques to upgrade an Oracle Multitenant environment:Everything at Once and One (or many) at a Time. This blog post describes the case how to Upgrade PDBs – One at a Time via unplug/plug/upgrade. I will describe all necessary steps. During some presentations, discussions etc people were left with the impression that it will be a very simple approach to unplug one or many PDBs from a CDB in lets say Oracle 12.1.0.1 and plug it into an Oracle 12.1.0.2 Container Database. Bingo, upgraded!

Well, unfortunately this is not true. In fact it …

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More than one PDB in the same directory?

Can you create more than one pluggable database (PDB) within the same directory?
And how does the file naming work? Considering the fact each PDB’s SYSTEM tablespace will be named system01.dbf by default the question is not trivial.

This question got asked by a customer during one of the workshops in Switzerland last week. And the solution is straight forward. Thanks to Roy for trying it out yesterday at 170 km/h on our way back from Stuttgart 🙂

Thanks 🙂

-Mike

Additional information:

Within ASM with OMF the file structure looks like this:

select con_id, substr(file_name,1,90),tablespace_name from cdb_data_files order by 
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Starting up 252 PDBs automatically?

In my recent posting I have explained the startup of many PDBs at the same time.

But once you startup the container database CDB$ROOT the PDBs will stay in MOUNT status. So how do you start them during CDB$ROOT startup (or immediately afterwards) in an automatic fashion?

A startup trigger will do this job.

CREATE OR REPLACE TRIGGER startup_all_pdbs
AFTER STARTUP ON DATABASE

BEGIN

EXECUTE IMMEDIATE ‘ALTER PLUGGABLE DATABASE ALL OPEN’;

END;

/

And of course you can use the EXCEPT command option to exclude one or more PDBs from the automatic startup.

CREATE OR REPLACE TRIGGER startup_all_pdbs_except_a_few
AFTER STARTUP

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Starting up 252 PDBs in Oracle Multitenant

What happens when you start up 252 PDBs (Pluggable Databases) with the Oracle Multitenant Option for the first time?

Interesting question, isn’t it? The expectation would be that this will happen within seconds as the SGA and therefore the shared memory segments are already allocated from within the CDB$ROOT (Container Database). But …

The following happens:
It takes minutes … hours …. In my tiny lab environment with just as little as 20 PDBs due to space constraints it takes over 30 minutes to startup 21 PDBs. Takashi Ikeda from Fujitsu Hokoriku Systems who did a great demo with the …

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