CORRECTION: After I published this blog post saying “April 2019” my fellow support colleagues changed the alert to “June 2019”. Just saying … the topic itself is still the same.
Simon Pane from Pythian talked to me at OUGN (Oracle User Group Norway) Conference about a recently released alert in MyOracle Support saying “Databases need to be patched to a minimum before June 2019“. He was curious if I know more details. I did some investigation but shortly afterward the MOS Note got updated as well. So here’s a quick summary of things you should be aware of – but most people won’t be affected I’d guess.
Databases need to be patched to a minimum before June 2019
We released MOS Note 2361478.1 – Oracle Databases Need to be Patched to a Minimum Patchset/PSU/RU level before June 2019 mid of February 2018 as an ALERT. Oracle Supported updated it a few days ago.
The alert refers to an SCN issue which came up a while ago. The system change number (SCN) is a logical, internal timestamp used by the Oracle Database. SCNs order events that occur within the database, which is necessary to satisfy the ACID properties of a transaction. The database uses SCNs to query and track changes.
When you have databases connected to each other via database links, you must ensure that the participating databases are on a certain patch level. The correct patch level will ensure proper functioning of database links.
Important fact:
These database releases are patched already out-of-the-box:
- 11.2.0.4
- 12.1.0.2
- 12.2.0.1 and newer
Only if you still use databases below 11.2.0.3 make sure you patched them to the right level or higher. Please see the table matrix in MOS Note 2361478.1 and find the minimum patches for your outdated versions.
If you still have questions you may either open an SR or raise it in this forum:
https://community.oracle.com/message/14710245#14710245
Just a recommendation on the side:
There are no bug fixes and security fixes for database releases below Oracle 11.2.0.4. Therefore you should upgrade your older database anyways. I’m pretty sure you know this already 🙂
Important Addition
Please read on here – this is an updated and newer blog post regarding the same topic, published in February 2019:
Further Information
You will find some pretty helpful notes on MyOracle Support regarding SCN Issues:
- MOS Note 2361478.1 – Oracle Databases Need to be Patched to a Minimum Patchset/PSU/RU level before April 2019
- Mandatory Patching Requirement for Database Versions below Oracle 12.2
- Frits Hoogland’s Blog Post with MANY details and insights
- MOS Note:1376995.1 – Information on the System Change Number (SCN) and how it is used in Oracle
- MOS Note:1393363.1 – Installing, Executing and Interpreting output from the “scnhealthcheck.sql” script
- MOS Note:12371955.8 – Bug 12371955 – Hot Backup can cause increased SCN growth rate leading to ORA-600 [2252] errors
- MOS Note:1376995.1 – System Change Number (SCN), Headroom, Security and Patch Information
- MOS Note:2329044.1 – SCN Issues: Checklist of Evidence to Supply
- MOS Note:1388639.1 – Evidence to collect when reporting “high SCN rate” issues to Oracle Support)
–Mike
Important heads-up, Mike.
One question: is 12.1.0.1 affected by this SCN problem too? I read 12.1.0.2, so that’s why my doubt.
Thanks!
Thiago,
please look at my blog posts where it says:
Important fact:
These database releases are patched already out-of-the-box:
11.2.0.4
12.1.0.2
12.2.0.1 and newer
Hope this helps!
Thanks
Mike
Ok, got it, so the database versions to be patched are: 11.2.0.3 and earlier and 12.1.0.1.
Hi,
Does anyone know if the compatible parameter affects this issue. We have a lot of 12.1.0.2 databases but the compatible parameter is set lower!
Thanks,
Stuart,
COMPATIBLE does not affect it – the patch has to be there. I will write another post next week and make such things more clear.
Cheers,
Mike
Mike, sorry my question, but for me wasn’t clear.
I have many databases with 10.2.0.3/10.2..0.4/10.2.0.5 version that accessing by dblink a 12.2.0.1
Need I to aplly this patch ?
Thanks.
Hi Gerson,
for 10.2.0.5 there seems to be a patch available now.
For 10.2.0.3, 10.2.0.4 and older databases there is no patch available.
But please check the MOS note and the SCN headroom scripts. These give you an indication how likely something happens or not.
And by all means, please open an SR with Oracle Support – they have specialists checking this with you.
Cheers,
Mike