ORACLE 文档 ID 2335265.1

Posted 2021-04-30 硅圣服务

In this Document

Purpose

Scope

Details

1. What are the recommended patchset/PSU/BP/RU levels ?

2. What is the timeline for moving to the recommended patchset/PSU/BP mentioned ?

3. What is the change introduced by the patches listed above?

4. What happens if the recommended PSU / patchset is not applied?

5. What about databases that are 10.2 or older, which are not listed in the table?

6. How can I check the details regarding the dblinks to and from a database?

7. Will there be any issues with the db links connecting two unpatched databases ? Or databases of older versions?

8. Will the dblinks involving a patched and an unpatched database, stop working immediately after June 2019?

9. What should I do, if the dblink connection from an older version database to a latest (or patched) version database fails, after June 2019?

10. What do we need to do for 11.2.0.4, 12.1.0.2 and 12.2.0.1 database releases?

11. Can I use Transportable Tablespace option from lower versions to 12c? Will it be affected due to this change?

12. Will there be any PDB unplug and plug issues from unpatched Databases on 12c?

13. Support and Questions

References

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APPLIES TO:

Oracle Database - Enterprise Edition - Version 11.1.0.7 to 12.1.0.1 [Release 11.1 to 12.1]
Oracle Database - Standard Edition - Version 11.1.0.7 to 12.1.0.1 [Release 11.1 to 12.1]
Oracle Database Backup Service - Version N/A and later
Oracle Database Cloud Exadata Service - Version N/A and later
Oracle Database Cloud Service - Version N/A and later
Information in this document applies to any platform.

PURPOSE

This support note provides additional info related to recommended patching requirement for Oracle databases versions 11.1.0.7, 11.2.0.3 & 12.1.0.1, to be done before June 2019.

 

SCOPE

 The document is intended for all DBAs.

DETAILS

Oracle Database versions 11.1.0.7, 11.2.0.3 & 12.1.0.1 are strongly recommended to be patched to the patchset/PSU levels mentioned below before June 2019 to resolve potential future issues in terms of interoperability of dblinks. No action is needed if you are running database releases/versions 12.2, 12.1.0.2 or 11.2.0.4. If you are still using 10.2 or earlier releases and using dblinks with later database releases, this note applies.

The interoperability of database clients with database servers is not impacted.

(Based on customer feedback, we are currently evaluating the need and feasibility of providing a patch for 10.2.0.5 and this note will be updated with that information at a later time.)

 

1. What are the recommended patchset/PSU/BP/RU levels ?

For database versions 10.2, 11.1.0.7, 11.2.0.3 & 12.1.0.1, ensure that all interconnected databases are in the below mentioned patchset/ PSU/BP levels or above:

 

Recommended patch levels

Patch Name	Patch Number
12.1.0.2.0 PATCH SET FOR ORACLE DATABASE SERVER	Patch 17694377
12.1.0.1.0 PATCH SET FOR ORACLE DATABASE SERVER	Upgrade to 12.1.0.2 or above Patch 17694377
11.2.0.4.0 PATCH SET FOR ORACLE DATABASE SERVER	Patch 13390677
DATABASE PATCH SET UPDATE 11.2.0.3.9 (INCLUDES CPUJAN2014)	Patch 17540582
DATABASE PATCH SET UPDATE 11.1.0.7.20 (INCLUDES CPUJUL2014)	Patch 18522513
ORACLE 11G 11.2.0.3 PATCH 28 BUG FOR WINDOWS **Patch 28 is withdrawn. Apply Patch 29 or above.	Patch 17906982 (Win x64) | Patch 17906981 (Win 32-Bit)  ** Patch 29 Patch 18075406 (Win x64) | Patch 18075405 (Win 32-Bit)
ORACLE 11G 11.1.0.7 PATCH 57 BUG FOR WINDOWS	Patch 18944208 (Win x64) | Patch 18944207 (Win 32-Bit)
QUARTERLY DATABASE PATCH FOR EXADATA (JAN 2014 - 11.2.0.3.22)	Patch 17747147
DATABASE PATCH SET UPDATE 10.2.0.5.171017 and Patch 14121009 [**requires extended support]	Patch <span< a="">26493118> and </span<>Patch 14121009 [WIP] ** requires extended support

 

In summary, 12.2.0.1 and higher releases, 11.2.0.4 and 12.1.0.2 patchsets have this fix included, while patches are available for 11.1.0.7 and 11.2.0.3 releases. If you have any other database server installations (e.g. 10.2.0.5, 11.2.0.2), you should be aware about potential dblink issues in future and consider applying the required patches or upgrading the databases, or not using dblinks with newer versions of databases.

 

2. What is the timeline for moving to the recommended patchset/PSU/BP mentioned ?

All databases are recommended to be at the above-mentioned release/patchset/ PSU/BP levels (or above) before June 2019.

3. What is the change introduced by the patches listed above?

These patches increase the database's current maximum SCN (system change number) limit.

At any point in time, the Oracle Database calculates a "not to exceed" limit for the number of SCNs a database can have used, based on the number of seconds elapsed since 1988. This is known as the database's current maximum SCN limit. Doing this ensures that Oracle Databases will ration SCNs over time, allowing over 500 years of data processing for any Oracle Database.
These recommended patches enable the databases to allow for a higher current maximum SCN limit. The rate at which this limit is calculated can be referred to as the “SCN rate” and these patches help allow higher SCN rates to enable databases to support many times higher transaction rates than earlier releases.

Please note that the patches only increase the max limit but the current SCN is not impacted. So, if all your databases don’t have any major change in transaction rate, the current SCN would still remain below the current maximum SCN limit and database links between newer (or patched) and unpatched databases would continue to work. The patches provide the safety measure to ensure that you don’t have any issue with dblinks independent of any possible future change in your transaction rate.

With the patches applied, this change in current maximum SCN limit will happen automatically starting 23rd June 2019.

 

4. What happens if the recommended PSU / patchset is not applied?

If this patch is not applied, the unpatched database will have a lower SCN rate or lower current max SCN limit.
The newer or patched databases will have higher SCN rate or higher current max SCN limit.
Therefore, there can be situations when the patched database is at a higher SCN level (due to the higher SCN rate allowance) and the unpatched database is at a much lower SCN level (due to lower SCN rate allowance).
When you open a dblink between these two databases, it has to sync the SCN levels of both the databases and if the SCN increase needed in the unpatched database for this sync is beyond it’s allowed SCN rate or current max SCN limit, then the dblink connection cannot be established.

This situation will not rise immediately after the change, but can potentially arise any time after 23rd June 2019.

 

5. What about databases that are 10.2 or older, which are not listed in the table?

You should be aware about potential dblink issues in future and consider about upgrading the databases or not using dblinks with newer versions of databases . If you continue to have such database links after June 2019, you may get run-time errors during database link operations (as explained above) and you would need to disconnect those database links at that time.

Based on customer feedback, we are providing patch on 10.2.0.5. 10g databases requires 10.2.0.5.171017PSU and Patch 14121009. Please note that these patches require extended support license.

 

6. How can I check the details regarding the dblinks to and from a database?

In order to identify database links, please review "Viewing Information About database Links" in Database Administrator's guide.
Please note that outgoing db links from a database can be identified via DBA_DB_LINKS view for all database releases.

select * from dba_db_links;

For 12.2 and later releases, you can also find out about incoming database links via DBA_DB_LINK_SOURCES view.

select * from dba_db_link_sources;

 

7. Will there be any issues with the db links connecting two unpatched databases ? Or databases of older versions?

The dblink connections involving two unpatched databases or two older releases are not affected by this change.

 

8. Will the dblinks involving a patched and an unpatched database, stop working immediately after June 2019? 

DB Links will not become unusable immediately after June 2019. However, might encounter errors in situations explained in question 4, at any point in time after June 2019.

 

9. What should I do, if the dblink connection from an older version database to a latest (or patched) version database fails, after June 2019?

Patch or upgrade the older version database to any patch level mentioned in the table.

 

10. What do we need to do for 11.2.0.4, 12.1.0.2 and 12.2.0.1 database releases?

No action is necessary. All the fixes needed are already included in these releases.

11. Can I use Transportable Tablespace option from lower versions to 12c? Will it be affected due to this change?

It is always OK to transport a tablespace from an unpatched database to a patched database.

When transporting a tablespace from a patched database to an unpatched database, if the SCN in the transportable set is higher than what the unpatched database can accept (which is not likely in the recent future), the plug-in operation will signal a user error. One can then fallback to using expdp.

12. Will there be any PDB unplug and plug issues from unpatched Databases on 12c?

Plug-in to any container database which are in 12.1.0.2 of above versions are not affected by this change. 12.1.0.2 and above contains the patch and hence will be able to cater higher SCN.

Plug-in to unpatched versions (12.1.0.1) can encounter errors, if the PDB has a high SCN, as explained in Q.11.

13. Support and Questions

 If you have any queries please post them in the Database community page: https://community.oracle.com/message/14710245#14710245

REFERENCES

NOTE:2361478.1 - Recommended patches and actions for Oracle databases versions 12.1.0.1, 11.2.0.3 and earlier – before June 2019