Sometimes Oracle Database 11gR2 complains about not being able to extend a (lob) segment with ORA-1691, but ASM monitoring based on USABLE_FILE_MB did not fire. Adding a new data file fails with ASM ORA-15041. I was under the impression this behaviour of ASM deserved some explanation. Situation Database Alert Log complains with ORA-1691: ORA-1691: unable to extend lobsegment MYUSER.SYS_LOB0013128030C00003$$ […]
My COLLABORATE16 look-at’s – an aftermath
From April 10th to April 14th 2016 many Oracle professionals congregated in Las Vegas. The three big U.S. user groups, the IOUG, the OAUG and the Quest User Group once again formed one of the best Oracle Conferences in the world: COLLABORATE16. I was honored to be there as a speaker, and glad to perform […]
Oracle SQL showing current expensive queries plus most expensive object from execution plan
Sometimes, it’s useful to see what’s currently going on in your Oracle Database. This query is meant to help with this task, that haunts every DBA from time to time. It’s just using v$sql and v$sql_plan, so no need for Enterprise Edition and Diagnostics Pack. Key features: find top buffer getters per execution from v$sql […]
Looking forward to speaking at COLLABORATE16 IOUG Forum
Yes, I did it again, submitted and got two papers accepted – speaking at COLLABORATE16 in Las Vegas (#C16LV) is always a highlight of the year! This time, it will be: The Bad One In Your Crop – SQL Tuning Analysis For DBAs 4:30 PM–5:30 PM Apr 11, 2016, Palm-A Oracle Core: 12c InMemory Column […]
Featured by Oracle Magazine
The Oracle Magazine featured me in its January / February 2016 issue. I really feel honoured and would like to say thank you for the opportunity! For details, please see the Performing Databases Blog post about the publication. […]
DOAG noon2noon RAC & Dataguard – Quick Report
There’s always something to learn – for example about Oracle RAC (Real Application Clusters) and Dataguard. And the old-school frontal teaching concept is boring, and more important, ineffective after a few hours of passive listening. So the German Oracle Users Group DOAG organized a “noon2noon” event: “Oracle RAC and Dataguard” this week in Würzburg (January 2 1st-22nd 2016). It was the […]
How to disable Oracle ACFS drivers / registry resource
Sometimes an installed ACFS can cause trouble, especially if we don’t or can’t use it (e.g. when not using an UEK Linux kernel, like with SuSE Linux Enterprise Server SLES). There’s lots of documentation how to create and maintain ACFS file systems, but how to get rid of ACFS at all wasn’t so easy to […]
Oracle 11g and 12c Cardinality Feedback Leads to Hundreds of Child Cursors
Sometimes, advanced features can bring advanced problems. Seeing a project with hundreds of child cursors with a different execution plan each, is never a pleasure, but there has to be a reason. In fact, we are talking about the “USE_FEEDBACK_STATS” reason in v$sql_shared_cursor. Its meaning is: “A hard parse is forced so that the optimizer can reoptimize […]
What is a “RAC Battle”?
RAC Battle [ræk ˈbæt̬l̩] What is a “RAC Battle”? It is a format of presenting technology – two experts, battling against each other on pros and cons of Oracle Real Application Cluster. Björn Rost (Oracle ACE Director) and Martin Klier (Oracle ACE) will fight Wednesday November 18th, 2015 11 am Nürnberg CCN (DOAG Konferenz 2015) […]
Oracle Database 11.2 Extended Support Waived
As announced today, Oracle waived the Extended Support for the period of February 2015 until May 2017. See the paper with details here. […]