AIX: “WARNING: Heavy swapping observed on system in last 5 mins.”

Quick one today!

Having message below in your 11.2.0.3 on AIX like this?

WARNING: Heavy swapping observed on system in last 5 mins. 
pct of memory swapped in [31.28%] pct of memory swapped out [3.81%]. 
Please make sure there is no memory pressure and the SGA and PGA are configured correctly. 
Look at DBRM trace file for more details.

Stand down, this issue is caused by unpublished Bug 11801934, mentioned in MOS False Swap Warning Messages Printed To Alert.log On AIX (Doc ID 1508575.1).

Basically happens because the v$osstat does not reflect proper stats for the swap space paging.

So, stay calm and see you next week!

Metric evaluation error start – Get dynamic property error,Dynamic Category property error,Computation of a critical dynamic property failed. Retries Completed.

Hi all,
Getting this error? OMS 12.1.0.3?
Ok… After an investigation on MOS and also a SR opened with Oracle is was pointed to relation with Bug 17575631 CLUSTER DB HOME PAGE ERRORS- REGIONS FETCH REAL TIME DATA WILL NOT BE DISPLAYED on Database Plugin.
It’s solved in OMS 12.1.0.4 and also in 12.1.0.5.1 EM Database Plugin Bundle patch.

 I’ll show you how to workaround it. 🙂

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DBA Brasil 2.0 – Oracle Database Backup Service for On-Premise Databases

Hello all,

Just letting you know I’ll be speaking in DBA Brasil 2.0 about Oracle Database Backup Service and specially about it use for On-Premise databases. I’ll be at room 94, from 9 to 10AM BRT.

The session is made for DBAs and Managers being focused on covering ROI, SLAs, Legal Aspect and Pros/Cons on this solution. This session includes a demo on this solution.

NewScreenshot 2017-04-12 Ă s 18.39.28

The participation is free! Please make your self present through: http://www.dbabr.com.br/dbabrasil2/inscricao/.

For complete list of sessions: http://www.dbabr.com.br/dbabrasil2/grade/

See you there!

Parameter Workarounds: Changing your Entire Database’s Behavior Because of a Query

This post is just a reflection, basically based on my last post about Adaptive Query Optimization/SQL Plan Directives. Several times we find some situations that can be solved by setting a parameter (likely a “_”) and we just proceed with an “alter system” disregarding about all the impact of this.

This is specially important when talking about “optimizer” parameters even for bugs causing ORA-600’s or performance issues… Changing those parameters in system will affect not only the SQL with the error but all SQLs in database, which may cause a really bad effect in some cases.

bad-idea-sign

Ok Matheus, but what can I do?
Let’s to the obvious and generally applied methods:

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Adaptive Query Optimization: SQL Plan Directives Causing High CPU after 12c Upgrade

Hello all!

As DBAs we are always being recommended by Oracle and also recommending to clients to update their databases, but we have to be aware about new features and their effects. This is the case of Adaptive Query Optimization and in this particular case on SQL Plan Directives.

SQL Plan Directives are one of the functionalities that compose the Adaptive Query Optimization in Oracle Database 12c. The basic idea is pretty interesting: The SQL Optimizer keeps reviewing bad (“suboptimal”, as they like to say) plans, tipically incorrect cardinality estimations and generates SQL plan directives, like for missing histograms or extended statistics.

In my case, just after the upgrade to 12c (made on Jan 27th), the CPU usage increased for the same report always ran in the database:

12c_upgrade

Ok, how to check it?

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