Single Tenant

Database Migration from non-CDB to PDB – Migration with Data Pump

You may have realized that there are a few techniques missing describing how to do a Database Migration from non-CDB to PDB – Migration with Data Pump is one of them. I will explain the most simple approach of going to Single- or Multitenant. It isn’t the coolest – and it isn’t very fast as soon as your database has a significant size. But it is not complex. And it allows you to move even from very old versions directly into an Oracle 19c PDB – regardless of patch levels or source and destination platform.

Database Migration from non-CDB to PDB – Migration with Data Pump

High Level Overview

Endianness change
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Database Migration from non-CDB to PDB – The Minimal Downtime Challenge

There are several pitfalls when you plugin a non-CDB into a CDB environment. I’d like to highlight some of them – and show you potential workarounds as well. This is part of a series of blog posts to make your migration from non-CDB to PDB a bit smoother.

Database Migration from non-CDB to PDB – The Minimal Downtime Challenge

Database Migration from non-CDB to PDB – The Minimal Downtime Challenge

When we start to look at a migration from non-CDB to PDB for an important system, regardless of migrating on-prem or to the cloud, reducing the downtime is very important. In this blog post I’d like to highlight the different aspects …

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Database Migration from non-CDB to PDB – The Fallback Challenge

There are several pitfalls when you plugin a non-CDB into a CDB environment. I’d like to highlight some of them – and show you potential workarounds as well. This is part of a series of blog posts to make your migration from non-CDB to PDB a bit smoother.

Database Migration from non-CDB to PDB - The Fallback Challenge

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Database Migration from non-CDB to PDB – The Fallback Challenge

As I work with customers on upgrades and migrations for a very long time, I know how important a proper fallback is.

When you attempt a migration from a non-CDB to PDB, you need to plan …

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Database Migration from non-CDB to PDB – Various Pitfalls

There are several pitfalls when you plugin a non-CDB into a CDB environment. I’d like to highlight some of them – and show you potential workarounds as well. This is part of a series of blog posts to make your migration from non-CDB to PDB a bit smoother.

Database Migration from non-CDB to PDB - Various Pitfalls

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Database Migration from non-CDB to PDB – Various Pitfalls

In all the previous blog posts of this series I tried to explain specific pitfalls, and how you can workaround them. This article is meant to collect the “leftovers”, the minor issues and pitfalls which you may not …

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Database Migration from non-CDB to PDB – The Patch Level Pitfall

There are several pitfalls when you plugin a non-CDB into a CDB environment. I’d like to highlight some of them – and show you potential workarounds as well. This is part of a series of blog posts to make your migration from non-CDB to PDB a bit smoother.

Database Migration from non-CDB to PDB - The Patch Level Pitfall

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Database Migration from non-CDB to PDB – The Patch Level Pitfall

When you consolidate on a larger scale, it is very likely that you have different patch levels in your database environments. But when you attempt to plugin a non-CDB into a CDB, you may see …

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Database Migration from non-CDB to PDB – The Component Pitfall

There are several pitfalls when you plugin a non-CDB into a CDB environment. I’d like to highlight some of them – and show you potential workarounds as well. This is part of a series of blog posts to make your migration from non-CDB to PDB a bit smoother.

Database Migration from non-CDB to PDB - The Component Pitfall

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The Component Pitfall

With component we mean the database component which you can find in DBA_REGISTRY – or CDB_REGISTRY. When Multitenant became available over 5 years ago, a decision had been made to make all options/components mandatory in a container database. This decision had to …

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Database Migration from non-CDB to PDB – The Time Zone Pitfall

There are several pitfalls when you plugin a non-CDB into a CDB environment. I’d like to highlight some of them – and show you potential workarounds as well. This is part of a series of blog posts to make your migration from non-CDB to PDB a bit smoother.

Database Migration from non-CDB to PDB - The Time Zone Pitfall

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Database Migration from non-CDB to PDB – The Time Zone Pitfall

Interestingly, there is no issue with different time zone settings within a single CDB. Your CDB$ROOT can be on DST V.32 whereas a PDB you plugin can be already on DST V.33. But only

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Database Migration from non-CDB to PDB – The COMPATIBLE pitfall

There are several pitfalls when you plugin a non-CDB into a CDB environment. I’d like to highlight some of them – and show you potential workarounds as well. This is part of a series of blog posts to make your migration from non-CDB to PDB a bit smoother.

Database Migration from non-CDB to PDB - The COMPATIBLE pitfall

Database Migration from non-CDB to PDB – The COMPATIBLE pitfall

When you migrate your non-CDB to PDB, in most cases the COMPATIBLE setting of the non-CDB will be lower than the setting of the receiving CDB. But still in this case you may see warnings. I will explain how to deal with …

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Database Migration from non-CDB to PDB – Typical Plugin Issues and Workarounds

In the previous blog posts I showed different approaches on how to migrate your database on a same Endianness platform into Multitenant. Whether you prefer to upgrade first or plugin first is up to you. I recommend upgrading first as this allows you a seamless fallback. But regardless of which approach you prefer, you may take care on potential pitfalls. Hence, this blog post is about Database Migration from non-CDB to PDB – Typical Plugin Issues and Workarounds. It may not be complete when I publish it and I may extend it later on. Let me know if you have …

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Database Migration from non-CDB to PDB – Clone via NON$CDB, upgrade, convert

The third option for plugging in a non-CDB is called Database Migration from non-CDB to PDB – Clone via NON$CDB, upgrade, convert. As I showed already in this blog post a while ago, your source must be at least an Oracle 12.1 database. And this technique can be used also only for same-Endianness migrations but does not apply if you’d like to migrate from Big to Little Endian. If your source database matches already the receiving CDB, no upgrade is necessary.

Database Migration from non-CDB to PDB – Clone via NON$CDB, upgrade, convert

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High Level Overview

Endianness change possible:
No
Source database versions: Oracle 12.1.0.2
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Database Migration from non-CDB to PDB – Plug in, upgrade, convert

This is my next blog post about Database Migration from non-CDB to PDB – Plug in, upgrade, convert. But what is different from the previous one? And why is it necessary? Since Oracle Database 12.2.0.1 you can plugin a non-CDB at first, the upgrade and convert it. And I’ll show you this technique here.

Database Migration from non-CDB to PDB – Plug in, upgrade, convert

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High Level Overview

Endianness change possible: No
Source database versions: Oracle 12.2.0.1 or newer (or 12.1.0.2 when CDB has shared UNDO)
Characteristic: Plugin into CDB first
Upgrade necessary: Yes, after plugin
Downtime: Plugin, copy (optional), upgrade and noncdb_to_pdb.sql
Minimal
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Database Migration from non-CDB to PDB – Overview

Today I’ll start a blog post series of several “how to” articles about database migration from non-CDB to PDB – Overiew. You’ll find a quick introduction below. And of course, the links to all the other related blog posts.

Database Migration from non-CDB to PDB – Overview

When you plan to move from non-CDB, the Oracle term for regular database deployments, to a Pluggable Database (PDB), you will migrate your database. It will become a PDB and run as part of a Container Database (CDB). This is a well known concept for several years now called Oracle Multitenant. If you …

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How to speed up Multitenant CUSTOM database creation

Why has the PDB$SEED such a strange setup?I usually create my container databases for testing with the CUSTOM option of DBCA. That allows me to specify exactly the components I’d like to have – or not. But I realized two things during the CUSTOM creation: It takes very long. And in the alert.log I see resize operations especially with the PDB$SEED during dictionary view creation. I see heap warnings. And recompilations. I did ask myself how to speed up Multitenant CUSTOM database creation.

Background Information

The PDB$SEED is the – I call it – “blueprint” pluggable database. It’s sole purpose is to allow you fast provisioning of …

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Cloning with Pluggable Databases in Oracle 18c

We had several discussions on the internal mailing lists the other day about cloning with Pluggable Databases in Oracle 18c (or 12.2.0.1). And I blogged about this topic a while ago but realized I may need to refresh this a bit.

Cloning with Pluggable Databases in Oracle 18c

My example from the old blog post still works fine. But I realized that I switched my database into read-only mode. Hence, I like to repeat it and check different options.

Cloning a 12.1 PDB into Oracle 18c

In the source CDB1 I create a fresh PDB first, then open it and create a cloning user with the necessary …

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Oracle 18.3.0 Multitenant: Compatibility Check does not work

Oracle 18.3.0 Multitenant: Compatibility Check does not workWhen I changed our Hands-On Lab to Oracle 18c, I encountered one strange issue in case I upgraded the UPGR database to 18.3.0 and wanted to plug it in afterwards. Before plugin I usually do a compatibility check. But this seems to fail. I checked my file, my paths, everything. But I couldn’t find the root cause. And yesterday I received an email from a customer who has a case open for over a week encountering a similar problem. And we both came to the conclusion for Oracle 18.3.0 Multitenant: Compatibility Check does not work under certain circumstances.…

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Drop a tablespace in a PDB with a Guaranteed Restore Point being active

Drop a tablespace in a PDB with a Guaranteed Restore Point being activeThis was an interesting question I received from Alain Fuhrer a couple of weeks ago: “Why can’t I drop a tablespace in a PDB whit a Guaranteed Restore Point being active?”. It’s important to note that the GRP is not active in the same but in another PDB.

An SR resolved the issue. But in case you face the same situation, here’s the solution.

Drop a tablespace in a PDB with a Guaranteed Restore Point being active

Simple test scenario. These are my PDBs:

show pdbs

    CON_ID CON_NAME			  OPEN MODE  RESTRICTED
---------- ------------------------------ ---------- ----------
	 2 PDB$SEED			  READ ONLY  NO
	 
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Different block sizes when you plugin?

Interesting case Roy came across a week ago with a customer in the US. The customer received a plugin violation because of different DB_BLOCK_SIZE between the source and the destination database. This happened regardless of unplug/plug or plugging in a non-CDB into a CDB. Hence the question came up: Can you have different block sizes when you plugin?

It should be possible – but you may need a tiny little workaround to make it happen.

The documentation as far as I can see was not helpful. MOS Note: 1935365.1 (Multitenant Unplug/Plug Best Practices) wasn’t very helpful either.

Different block sizes

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Can you select a PDB’s character set?

Can you select a PDB's character set?Since Oracle Database 12.2.0.1 a Multitenant container database can host PDBs with different character sets. This was a huge restriction in Oracle Database 12.1., at least outside the US and Canada. Here in Germany alone you may find plenty of different database character sets, for instance WE8ISO8859P1, WE8ISO8859P9, WE8ISO8859P15, WE8MSWIN1252, maybe still some old WE8DEC – and of course the unicode ones UTF8 and AL32UTF8. But the question is: Can you select a PDB’s character set when you provision a new PDB?

Mixing PDB character sets in Oracle Database 12.2.

One of the limiting restrictions in Oracle 12.1 Multitenant …

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noncdb_to_pdb.sql – why does it take so long?

What is noncdb_to_pdb.sql?

noncdb_to_pdb.sql - Why does it take so long?The script noncdb_to_pdb.sql gets run only once in the life span of your database. It gets executed when a regular Oracle database (non-CDB) gets move to become part of a Single-/Multitenant deployment as a pluggable database (PDB). But why does it take so long?

You will never run this script again for this database. The script is a sanity script to clean up and change things in a non-CDB, and unite it finally and irreversible with the CDB.

How long does it take to complete?

Runtime varies a lot. It depends mainly on the number of objects …

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Non-CDB architecture still exists in Oracle Database 12.2.

I received a question whether the Non-CDB architecture still exists in Oracle Database 12.2.from 3 different colleagues in the past week:

“Does Oracle Database 12.2 still allow us to create non-CDB databases?”

And as I get this question at every customer-facing workshop these days as well before being able to talk about Single/Multitenant – I think it is important to clarify it. The statement is misleading. And I can’t blame anybody about misreading it.

Is the non-CDB architecture still available/supported in Oracle Database 12.2?

I did blog about it a while ago – but Google is not always your …

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Install components in Multitenant ALWAYS with catcon.pl

I did blog several times about how to remove an unwanted component from a database. But yesterday I came across this interesting scenario worth a blog post.

How to install a component afterwards in Single-/Multitenant?

I haven’t checked all the MOS Notes but I recognized that some MOS Notes explaining how to (re-)create a component such as JVM are not updated to deal with a Single and/or Multitenant environment as they simply call the scripts from SQL*Plus. But the key to script execution in such an environment is catcon.pl, the perl driver meant to execute database scripts not only in …

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Having fun with PDB LOCKDOWN PROFILES

In Oracle Database 12.2 (available in the Oracle DBaaS Cloud) there’s a new functionality called “PDB LOCKDOWN PROFILES“. Actually the parameter came already in undocumented and not functional in Oracle Database 12.1.0.2 (see here).

PDB Lockdown Profiles

PDB Lockdown Profiles are meant as a granular way to restrict or enable access – mostly under the aspect of using the database in a highly shared environment but requiring security. The idea is to embed restrictions on-top of a grant, i.e. taking away certain things. As an example you could allow a user logged into a certain PDB …

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SPFILE Parameter: max_pdbs – a must for Single Tenant

Sometimes my job has a aspect making me smile at the end of the day 😉

I sat together with Johannes Ahrends during a talk at the OUGN Conference on the boat from Oslo towards Kiel. And we were discussing afterwards why there’s no official way to limit the number of PDBs which will be essential for customers wanting to go the Single Tenant track. I had my Hands-On environment up and we played a bit in the break recognizing that a constraint on CONTAINER$ won’t be the correct solution as unplug/plug operations leave leftovers in it unless you …

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PDB unplug/plug/patch with PSUs or BPs

This question was posted on the blog a few days ago referring to my previous blog posts describing the two techniques to upgrade in an Oracle Multitenant environment:

Question: 

We are planning to upgrade from 12.1.0.2.1 to 12.1.0.2.5.
The plan is to create new 12.1.0.2.5 oracle home and
gradually moving PDB from 12.1.0.2.1 to 12.1.0.2.5.
Should I follow the same steps?
Is there any document for what we want to do?

And luckily there is a MOS Note out there describing the steps:

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DROP PLUGGABLE DATABASE – things you need to know

Directly after my DOAG (German Oracle User Group) Conference presentation about “How Single-/Multitenant will change a DBA’s life” Martin Bach (Enkitec) approached me and told me about his experiences with the DROP PLUGGABLE DATABASE command and future recoverability.

Martin discovered that once you issued the DROP PLUGGABLE DATABASE command you can’t reuse a previously taken backup of this particular PDB anymore and recover the PDB into this existing CDB. I wasn’t aware of this and I’m glad that Martin told me about it.

Actually only the meta information in the controlfile or the RMAN catalog will be deleted. But archive

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