About

Martin Klier

usn-it.de

Oracle Automatic Big Table Caching – an improvement, not a fix

Too much TABLE ACCESS FULL in your Oracle Database? Thus, SQL elapsed time too slow for the demand? Plenty of Buffer Cache to create a temporary fix? maybe you want to consider Automatic Big Table Caching. Usually, Oracle only does Full Table Caching for small tables. Big ones will only use the Buffer Cache for the current chunk […]

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Oracle 11g unable to extend datafile but ASM disk group shows free space

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$$ […]

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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 […]

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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. […]

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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 […]

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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 […]

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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) […]

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