Best Practice

Zero Downtime Upgrade of Timezone Data in Oracle 21c and 23c?

There is a feature in Oracle Database 21c I planned to write about for a very long time: Zero Downtime Upgrade of Timezone Data in Oracle 21c and 23c. This sounds very promising – but let us take a closer look together in this blog post.

Time Zone Upgrade?

There is of course an ongoing discussion whether and when you should upgrade the DST version of your database to a current value. Since we all live in a more and more globalized world, this topic becomes more and more important. Even more important …

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Virtual Classroom Seminar #15: Data Pump Best Practices on April 5, 2023

We are quite busy these days. And I am lagging behind in answering your comments on the blog. So please be patient, nothing will be lost. Meanwhile, we work hard on the slides for our next Virtual Classroom Seminar #15: Data Pump Best Practices on April 5, 2023.

What will be the topic?

Data Pump Best Practices and Real World Scenarios tells you already what we are planning to do. After we had a “Data Pump Deep Dive with Development” seminar last year (time flies so quickly), we decided that we should tackle …

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A change in Oracle 12.2 and 19c with MV Refresh Stats Collection

It’s not easy for me to put the topic into a searchable title for this blog post. The feature or change I will write about today came in actually with Oracle Database 12.2.0.1. But since many of you will move directly from Oracle 11.2.0.4 or 12.1.0.2 to 19c, the Long Term Support release, it may affect you as well. So let me explain a change in Oracle 12.2 and 19c with MV Refresh Stats Collection.

 

A customer story

The local Support team asked me a few weeks ago whether I have heard …

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Certifying an application on a specific RU-only is wrong

Well, there are still 80+ comments I need to answer and reply to on the blog. So please be patient – nothing gets deleted or ignored. But it happens that a topic crosses my inbox, and I need to blog about it right now. Today, it is a case where a customer asked me for advice, and mentioned on the side that they are going to 19.6.0 in OCI. In this relation I’d like to explain why Certifying an application on a specific RU- only is wrong.

What’s the story?

At first, …

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Can I cleanup the previous Patch Bundles with opatch?

Today I will step on mined territory. Can I cleanup the previous Patch Bundles with opatch?  Or can I just wipe out the old ones? That is a question which will bring people with temper quickly close to explosion. But let me start step by step, especially for those of you who aren’t familiar with this topic.

Can I cleanup the previous Patch Bundles with opatch?

The secret directories

You  L O V E  secrets, don’t you? No? Well … then let me start with a secret which isn’t a secret to most people making it even more obscure.

When you install a patch with opatch or opatchauto, …

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Upgrade Seminars 1 and 2 – A quick recap, slides download and more

Thank you for participating in the first two seminars. Roy and I did already the “Release and Patching Strategy” webinar on Tuesday, June 23. And today  “AutoUpgrade to Oracle 19c”. So it time for Upgrade Seminars 1 and 2 – A quick recap, slides download and more.

Upgrade Seminars 1 and 2 - A quick recap, slides download and more

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Slides Download

I uploaded the slides already to https://mikedietrichde.com/slides/#WEB2020. Of course, I will upload the other slide decks as well to the same location.

Seminar Recordings

As soon as the recordings page has been completed, we will send out an email. And I will post the links …

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Less is more – faster Oracle database upgrades with less memory

The title of this post sounds a bit weird: Less is more – faster Oracle database upgrades with less memory. Just a few weeks ago, I posted about How long will my upgrade take … revisited. And Daniel adds a very useful piece to the upgrade speed topic. Read about his tests below.

Less is more – faster Oracle database upgrades with less memory

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Less is more – faster Oracle database upgrades with less memory

by Daniel Overby Hansen, Senior Principal Product Manager,
Oracle Database Upgrades and Cloud Migrations
Less is more – faster Oracle database upgrades with less memory by Daniel Overby Hansen

Daniel Overby Hansen

Mike and I had a talk with a customer the other …

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Oracle Database Upgrade – Quick Start Guide available

If you don’t deal with databases upgrades every day but just want to see a short and good overview about how to do a successful database upgrade, then this is for you. A few days ago we’ve made the Oracle Database Upgrade – Quick Start Guide available for download.

Oracle Database Upgrade - Quick Start Guide available

Photo by Daniel Leone on Unsplash

Why a Quick Start Guide?

If database upgrades are your daily topic, you won’t need our quick start guide. But if you need a short overview about the right steps to approach an upgrade, this guide is for you. Thanks to my PM colleague,

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How long will my database upgrade take? Revisited …

I received this question twice within a few days. And I remember that a tiny little while ago I wrote something on the blog about it. But as this “while” is 11 years ago, I came to conclusion to refresh this topic – and write something about How long will my database upgrade take? Revisited …

How long will my database upgrade take? Revisited ...

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Is there a query?

At first, before I go into details, an important fact upfront: There is neither any query nor any tool giving you a rough estimate or precise figure of how long your upgrade will

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ORA-1403 during TEXT / CONTEXT post upgrade

When you see an ORA-1403 during TEXT / CONTEXT post upgrade phase, regardless of using AutoUpgrade, dbupgrade, catctl or DBUA, no worries. Two people reported this to me this week. And my dear support colleague Klaus Herndl told me about the existing MOS note. But there is a bit more to explain, especially as the bug is non-public and the MOS note doesn’t tell you when this can happen.

ORA-1403 during TEXT / CONTEXT post upgrade

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What happens?

This is the error pattern you may see during the post upgrade phase when Oracle Text is installed in your database:

Oracle Database 
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Be aware when you use _ORACLE_SCRIPT in scripts

Recently I came across this when I gave a Multitenant workshop at a German customer. As part of the workshop I explained the _ORACLE_SCRIPT statements you will find in almost all scripts in ?/rdbms/admin. And one of the DBAs gave me a bright smile. He mentioned: “We use it already everywhere to avoid strange errors”. But be aware when you use _ORACLE_SCRIPT in scripts. I will explain, why this can be dangerous.

Be aware when you use _ORACLE_SCRIPT in scripts

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What does _ORACLE_SCRIPT do?

First of all, this is an underscore parameter. Hence, you won’t find it in the Oracle …

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Save Patching Downtime with Oracle Multitenant?

At OOW 2019 we announced that you can have up to 3 user-created pluggable databases (PDBs) per container database (CDB) without having a Multitenant license. And in this blog post I’d like to demonstrate how you can save patching downtime with Oracle Multitenant.

The Concept

The idea this entire process settles on is very simple. When you create a fresh container database in the target (already patched!) environment, you don’t have to patch this one. You only have to relocate the PDB from the source into the target CDB. In addition, only datapatch needs to be executed. As the …

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When and how should you change COMPATIBLE?

When and how should you change COMPATIBLE?

COMPATIBLE is an almost mystic parameter. It has a default setting for each release. But if you try to find more information what it really does, you won’t be very happy. And in reply to my previous blog post about whether you need to change COMPATIBLE when you apply an RU, I received the following question: When and how should you change COMPATIBLE?

What does COMPATIBLE do?

To find an answer to this question, I consulted the documentation at first. And I found this:

  • COMPATIBLE
    Setting COMPATIBLE ensures that new features do not write data formats or structures
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Should you change COMPATIBLE when you apply an RU?

I have a million ideas for blog posts. But I like it even more when people ask me to explain something on the blog which isn’t there yet but may be interesting for others as well. And Robert Ortel mailed me the other day and asked if he should change COMPATIBLE when he applies an RU for Oracle 18c. That’s a good question. And I doubt that the documentation has a good recommendation.

Should you change COMPATIBLE when you apply an RU?

No.

Should you change COMPATIBLE when you apply an RU?

That’s a short blog post this time, isn’t it? 🙂 But honestly, you shouldn’t touch COMPATIBLE for …

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Creating CDBs and non-CDBs with less options

Creating CDBs and non-CDBs with less optionsI wanted to write up this blog post a long time ago. When Helen Vanderheide did ask me a few weeks ago if she can omit catoctk.sql during the creation of the database, I realized that I should update my previous blog posts about Creating CDBs and non-CDBs with less options. And of course, the following is usable with non-CDBs as well.

You’ll find an example and especially the component dependency matrix below as well as many links to related blog posts at the end. If you don’t want to read all this, just scroll down to the Summary

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New preupgrade.jar and changes in MOS Note:884522.1

We read and listen to your comments. And that’s why my team mate Byron has added a new preupgrade.jar and changes to MOS Note:884522.1. One reader commented that MOS Note:884522.1 (How to Download and Run Oracle’s Database Pre-Upgrade Utility) does not explain how to “run” the preupgrade tool even though it mentions this in the note’s title.

New preupgrade.jar and changes in MOS Note:884522.1

New preupgrade.jar and changes in MOS Note:884522.1

With MOS Note:884522.1 you can download always the most recent versions of the Oracle 18c and 12.2 preupgrade.jar tools, of the Oracle 12.1.0.2 preupgrd.sql and utluppkg.sql. And you’ll even find the last utlu112i.sql for upgrades …

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Oracle Database 18c: A new preupgrade.jar is available

In case you plan to upgrade a database to Oracle Database 18c: A new preupgrade.jar is available for download from MyOracle Support (MOS).

Oracle Database 18c: A new preupgrade.jar is available

Oracle Database 18c: A new preupgrade.jar is available

Please download it – as always – from MOS Note:884522.1.

The same MOS note will get you also the most recent versions of the preupgrade.jar for Oracle Database 12.2.0.1 upgrades. Of course you can download also all previous incarnations such as preupgrd.sql for 12.1.0.2 upgrades and even utlu112i.sql for 11g upgrades.

What’s new in preupgrade.jar for Oracle 18c upgrades?

There are a few important and good Improvements and …

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Multiple Hops – Which should be the intermediate release?

Multiple Hop Oracle Database UpgradesThis is a topic which doesn’t come up very often. But if it does come up from time to time, and the documentation may give you advice – but as I realized – it does not always give the best advice. When you have to do multiple hops – which should be your intermediate release?

I posted something about this topic a while back:

What are Multiple Hops?

We speak of multiple hops in relation to database upgrades when your source release does not allow you to upgrade directly …

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preupgrade.jar January 2018 (Build 11) is available now

A new version of the preupgrade.jar January 2018 (Build 11) is available now.

Please download it from MOS Note:884522.1.:

preupgrade.jar January 2018 (Build 11) is available now

MOS Note: 884522.1 – How to Download and Run Oracle’s Database Pre-Upgrade Utility

Please always download the most recent version as this one is much newer with a lot of improvements compared to the version you get with the default installation. Major changes since the first drop are:

  • Added load only capabilities.
  • Improved the interaction with OS
  • Added more obsolete/deprecated parameters
  • Improved IPC calls on Windows
  • Added functionality for aud$unified table partitions.
  • Added preupgrade and postupgrade automatic fixups
  • Check for
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Book Recommendation: Oracle Database Upgrade and Migration Methods

Thanks guys, I received my copy 🙂

Book Recommendation: Oracle Database Upgrade and Migration Methods

APRESS: Oracle Database Upgrade and Migration Methods

And today I’d like to write a book recommendation: Oracle Database Upgrade and Migration Methods.

The book got authored by these 3 true database upgrade and migration experts:

And it’s cool book mostly for techies. It has plenty of examples in all details. A lot of good tips and tricks (for instance: Disable the Broker when you upgrade your database with standby in place). All of it from …

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utlrp.sql – How to decrease resource consumption with utlprp.sql

 utlrp.sql - How to decrease resource consumption with utlprp.sqlJust being back from Oracle Open World 2017 I’m working on the open topics, the homework, the follow-up activities. And I took several notes during OOW when customers asked me about things I’ve seen before.

One topic I wanted to write about a long time ago already: utlrp.sql – How to decrease resource consumption with utlprp.sql.

Where it started

Actually it’s all Uwe’s fault (Uwe Kirchhoff is one of my best and oldest friends at Oracle and one of the best ACS guys I can think of). Uwe told me this story about a customer case he …

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Other people’s thoughts: “Should you upgrade to 12c?”

You still don’t believe me yet when I say: You can’t seriously wait for the so called 2nd release of Oracle Database 12c as it will be an entirely new release again? And you haven’t upgraded yet to Oracle Database 12.1.0.2 for various reasons?

Then sometimes it’s good to listen to other people’s opinions – and I’m happy to share this 6 minute video by Tim Hall (very well known for his great page oracle-base). Listen to Tim and his Thoughts about Upgrading to Oracle Database 12c. And don’t get disturbed that he’s driving on the wrong …

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The MAGIC Questions

Almost every week Roy, Carol and I receive one or more emails in the following style:

“Hey, we (or my customer) plan(s) an upgrade to Oracle 11g. We (or the customer) wants zero downtime. Currently we (or they) are on AIX with Oracle 10g (and someold  9i) databases. Can we get an advice please?”

or another one here …

“Upgrade from 8i to 11g. The customer’s database is 28 TB (quite big!). Downtime is 5-6 hours. It’s on AIX. And it’s an it’s an Oracle EBS database”

Well, in both cases we lack a lot of useful information – or …

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Potential check for corruptions

Having a corruption somewhere in the database is one of the worst case scenarios I could ever imagine – especially if it “sleeps” somewhere in the data dictionary. Recently I did talk to a customer who encountered a failing upgrade due to a data dictionary corruption gotten introduced in an earlier release.

What can you do to check your database(s) prior to an upgrade or generally from time to time? Actually I know now two powerful possibilities:

  • hcheck.sql
    See MOS Note:136697.1
    This script will check for known problems in Oracle8i, Oracle9i, Oracle10g
    and Oracle 11g.
    You will need
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Will gathering fixed object stats reduce recompilation time post upgrade?

Interesting question, isn’t it?
Will the time to recompile invalid objects post upgrade decreased once fixed object stats have been gathered?

First of all fixed object stats on X$-tables won’t be gathered by default [This will change with Oracle 12c where it is part of the Auto Stats Gathering job].
X$ structures are undocumented. V$ views are build on top of them and
should only be used even though it might be sometimes useful to access
X$ tables such as X$BH (buffer headers – contains information describing the current contents of a piece of the buffer cache

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