Flaws and Pitfalls

OJVM datapatch fails with ORA-29532 – but the root cause is noncdb_to_pdb.sql

Kudos to Robert Ortel who brought this nice misbehavior to my attention. And even though it looks like this would be an OJVM issue, it is caused by noncdb_to_pdb,sql, the script which is used to convert a non-CDB to a PDB. When you apply an OJVM patch, OJVM datapatch fails with ORA-29532 – but the root cause is noncdb_to_pdb.sql.

OJVM datapatch fails with ORA-29532 - but the root cause is noncdb_to_pdb.sql

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It’s a bit tricky

First things first. This is not a blog post to blame OJVM. The problem just happens because datapatch for an OJVM patch touches data in the dictionary which hasn’t …

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OPatch Alert: Be aware of cleanup issues – and the JDK version

This is just a quick alert blog post for Friday with an OPatch Alert: Be aware of cleanup issues – and the JDK version. And thanks to several people who either commented or mailed me directly and asked if I could alert others as well.

OPatch Alert: Be aware of cleanup issues - and the JDK version

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OPatch cleanup issue

At first, you may have read earlier this week my article about patching my environments with the April 2020 bundle patches. For my patch activity, I’ve had to exchange my OPatch versions for 11.2.0.4, 12.2.0.1 and 19.7.0. And I guess, I would have had …

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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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Issues with seed databases, patch bundles and OJVM in 19c

I really rely on people telling me about issues they saw. And in this case, it happened twice within a few days. At OOW London, a customer came after my talk and told me about invalid objects and an incredible long recompilation time. In fact, he had to apply an OJVM patch in order to solve this. When I returned home, Jure commented on the blog about a very similar issue. I spent some time on the weekend to check it out. And I realized: There are issues with prebuilt seed databases and OJVM in 19c.

Issues with seed databases, patch bundles and OJVM in 19c

Photo by Max

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APEX is invalid after upgrading to 12.2 – ORA-20001

We are running the AutoUpgrade-for-RAC beta test since last week. And the first issue one customer encountered … is neither an AutoUpgrade nor a RAC issue. It has to do with APEX and SPATIAL, and missing grants. APEX is invalid after upgrading to 12.2 – ORA-20001

APEX is invalid after upgrading to 12.2 - ORA-20001

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What is happening?

You are doing an upgrade to Oracle Database 12.2.0.1. And you receive a number of errors during the component validation phase.

19:04:14 SQL> EXECUTE dbms_registry_sys.validate_components;
...(19:04:15) Starting validate_apex for APEX_180100
ORA-20001: MISSING GRANT: grant execute on "MDSYS"."SDO_DIM_ARRAY" to APEX_180100
ORA-20001: MISSING GRANT: grant execute on 
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GI Patch 28553832 may be needed before you upgrade to 19c

Thanks to my colleague Sebastian Alasino who works in the MAA team out of the UK. Sebas highlighted this issue to. And I’d like to share it with you when you attempt to upgrade Grid Infrastructure to Oracle 19c. If you have the Docker RPM  installed and you were lazy on patching, then GI Patch 28553832 may be needed before you upgrade to 19c.

GI Patch 28553832 may be needed before you upgrade to 19c

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What is the issue?

If the Docker Engine RPM is installed and your GI version is 12.1.0.2, 12.2.0.1 or 18c below a certain patch level, the CSSD demon fails to …

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ORA-1722 when upgrading to 19.4.0 or 19.5.0 on Windows

Oh boy – I try to avoid blogging about errors on a specific platform. But as this topic was brought to my attention now 3x in 2 weeks, I think I’ll send it out. And I hope you won’t hit this ORA-1722 when upgrading to 19.4.0 or 19.5.0 on Windows.

ORA-1722 when upgrading to 19.4.0 or 19.5.0 on Windows

What is failing?

The database upgrade only on the MS Windows platform fails when you attempt to upgrade to 19.4.0 or 19.5.0. This means, you downloaded and installed 19.3.0. And then you followed our advice and applied one of the most recent Release Update – ideally 19.5.0, the October 2019 …

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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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In case you miss DBMS_OPTIM_BUNDLE … again …?!?

In case you miss DBMS_OPTIM_BUNDLE ... again ...?!?

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I’m tempted to copy and paste my blog post about DBMS_OPTIM_BUNDLE from February 2019, and exchange only 12.2.0.1 with 19c. But in this case the root cause is different. So this blog post is meant for Oracle 19.3.0 to be precise – in case you miss DBMS_OPTIM_BUNDLE … again … ?!?

Information about DBMS_OPTIM_BUNDLE

You will find a lot of information about DBMS_OPTIM_BUNDLE, what it does, since which release it exists and much more in these blog posts:

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Data Pump: The Time Zone Pitfalls

Data Pump: The Time Zone Pitfalls

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Last week a very experienced colleague called me. He had issues with an export dump taken from an Oracle 20c database importing into 19c. It failed. So this blog post is about Data Pump: The Time Zone Pitfalls.

The Case

Usually you will see this issue only when you try to export from a higher version, and then attempt to import into a lower one. But the same thing can happen when you patched your databases partially with a newer time zone patch regardless of the version.

My colleague saw this error:

impdp system/welcome1@//localhost:1521/MYDB 
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You MUST patch 12.1.0.1 and 11.2.0.3 and older databases before June 2019

First of all, this blog post is not new. I blogged about this SCN topic a while ago already. But some of you seem to operate still older databases for various reasons. And even if you think that you are safe, double check for any older databases in your environments. You MUST patch 12.1.0.1 and 11.2.0.3 and older databases before June 23, 2019. And just to be clear: June 23, 2019 is going to happen in less than 4 months.

You MUST patch 12.1.0.1 and 11.2.0.3 and older databases before June 2019

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Who is NOT affected?

If you use the following Oracle database releases …

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In case you miss DBMS_OPTIM_BUNDLE in 12.2

Strange things happen sometimes. I got alerted by a customer before Christmas about package DBMS_OPTIM_BUNDLE missing after applying a Release Update. I’ve had a conversation with Nigel Bayliss, the Optimizer PM – but Nigel hasn’t heard of such things either. We both investigated but couldn’t reproduce the issue. But after the end-of-the-year holidays I received similar messages from other customers. In case you miss DBMS_OPTIM_BUNDLE in 12.2, then this blog post should help you.

In case you miss DBMS_OPTIM_BUNDLE in 12.2

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What is DBMS_OPTIM_BUNDLE?

I blogged about this package in the past already several times:

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Direct INSERTs into HCC tables may be slower since Oracle 12.2

I work with several customers at the moment on their Oracle 12.2/18c “go live” projects. And one of these customers encountered a strange issue when comparing Oracle 11.2.0.4 to Oracle 12.2.0.1/18.3.0: Direct INSERTs into HCC tables may be slower since Oracle 12.2. Actually in this particular case, significantly slower. Read below why this can happen and how the workarounds look like.

Hybrid Columnar Compression

There’s a lot of material to read and study about Hybrid Columnar Compression (HCC). With HCC we store the same column for a group of rows together. The data block does not store data in row-major …

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Where does the database link SYS_HUB come from?

This blog lives a lot from customer’s feedback and updates. And these days, Nicolas Jardot from dbi-services in Switzerland sent me an email asking: Where does the database link SYS_HUB come from? And if he can delete it or if it has any deeper purpose. Neither Google nor MOS reveal a lot of useful information

Where does the database link SYS_HUB come from?

Where does the database link SYS_HUB come from?

I took my vanilla 18.3.0 database in our hands-on lab and check:

column owner format a5
column db_link format a12
column username format a12
column host format a12

select con_id, owner, db_link, username, host from cdb_db_links;

    CON_ID 
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RMAN Backup Gives RMAN-06091: No Channel Allocated for Maintenance

RMAN Backup Gives RMAN-06091: No Channel Allocated for MaintenanceI really don’t want to turn this blog into an accumulation of issues and flaws. But as I explained many times before, the blog for me is also a way to dump information I likely will need the sooner or later again.

Recently I blogged about another RMAN issue in Oracle 12.2.0.1 with traces. This was fixed with the July 2018 RU for Oracle 12.2.0.1. But the issue below about which Piero Ferraz from Brazil alerted me (thanks!!!), happens in exactly this RU.

RMAN Backup Gives RMAN-06091: No Channel Allocated for Maintenance

This issue gets introduced with the July …

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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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Drop public synonym XMLCONCAT prior to upgrade

Thanks to my team mates, Cindy and Hector, who alerted me on this newly detected issue. When your database has been upgraded from release to release, it could happen that a public synonym XMLCONCAT exists. And before you upgrade to Oracle 12.2.01 or Oracle 18c you must drop this public synonym to avoid upgrade errors.

Drop public synonym XMLCONCAT prior to upgrade

The public synonym XMLCONCAT in pre-9.2.0.2 Oracle databases pointed to a PL/SQL function of the same name. In 9.2.0.2, this PL/SQL function was changed to a C function.The public synonym was no longer needed nor pointing to a …

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Data Pump 12.1.0.2 – Wrong Dump File Version – ORA-39142

Data Pump 12.1.0.2 - Wrong Dump File Version - ORA-39142Again I’ll have to thank my colleague Roland Gräff from the German ACS Support team in Stuttgart for bringing this into our radar. Roland alerted me a week ago about an issue with exports in Oracle 12.1.0.2 only when you are on a certain patch level. I summarize the issue here under Data Pump 12.1.0.2 – Wrong Dump File Version – ORA-39142.

In the below blog post you will learn about the actual issue, where it happens and when, and of course how to workaround it.

When does it happen?

The issue I will describe below happens only with

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RMAN backup generates traces in Oracle 12.2.0.1

RMAN backup generates traces in Oracle 12.2.0.1Oracle 12.2.0.1 seems to be the “tracing” release without further patch or parameter treatments. After posting about MMON unconditional traces in Oracle 12.2.0.1 a day ago, I received a couple of comments either on the blog, via LinkedIn or Twitter regarding other trace facilities in Oracle Database 12.2.0.1. One of them is the case that RMAN backup generates traces in Oracle 12.2.0.1.

And please, very important upfront:
Oracle Database 12.2.0.1 is a very stable and reliable release based on all the customer feedback Roy and I received so far. For instance, when we check for optimizer issues …

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MMON unconditional traces in Oracle 12.2.0.1

MMON unconditional traces in Oracle 12.2.0.1I love visiting customers onsite. Last week I visited die Mobiliar in Bern, Switzerland. I received a list of open issues to discuss – which is very good to prepare a visit. And when we all were sitting together there was this “Ah, one final thing”. They have an issue with traces the databases writes every few seconds. As a remedy the DBAs increased the backup interval to remove the traces as otherwise the system would potentially run out of inodes or space. All the traces had the same pattern. And I learned quickly: these are MMON unconditional traces in …

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