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 dbms_workload_repository awr_global_report_text fails with ORA-06553 PLS-307

My last post was about generating AWR reports from SQL – not a very complicated case. “But” – little word, big meaning. And suddenly we get a strange error message. In my example, I was especially interested in a Real Application Cluster’s “global” report. The subprogram call for that purpose is dbms_workload_repository.awr_global_report_text(), accepting the DBID, begin […]

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How to create an Oracle AWR report with SQL and PL/SQL

AWR is a great tool (but needs diagnostics pack). It can create very useful reports for performace analysis over a given period. Most people will pull the AWR Report  from the OS level, with ‘@?/rdbms/admin/awrrpt.sql” (or one of the other scripts there). But sometime it’s not possible to access a database server’s OS level, or […]

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DOAG BI Conference: Oracle Core (for Beginners): In-Memory Column Store

On Thursday, April 23rd I’m speaking at DOAG BI 2015, the leading Oracle Business Intelligence Conference in Germany. (#DOAGBI15) My contribution is: “Oracle Core für Einsteiger: In-Memory Columns Store”. The lecture will show, how the Oracle Database In-Memory option works “under the hood”, and how it is used to the best effect. Please find the presentation […]

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Speaker at DOAG 2015 Datenbank – “Oracle Core für Einsteiger: InMemory Column Store”

The DOAG 2015 Database conference is on the horizon: June 16, 2015 in Düsseldorf, Germany. I’m proud to announce my participation as a speaker, as I was honoured with in the years before. This year, my part will be a new “Beginners” talk in German: “Oracle Core für Einsteiger: InMemory Column Store”   Abstract: ==================== Der Vortrag richtet […]

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Oracle: Did my SQL get worse over time? (AWR query)

Sometimes, we get statements to look at, and are told “it’s getting worse and worse”. Since DBAs are well advised not to take anything for granted and only to believe what they see with own eyes, here comes a SQL on AWR to see Buffer Gets per Minute, over time. select s.BEGIN_INTERVAL_TIME, round(t.BUFFER_GETS_DELTA/ 0.0001+ (extract […]

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DOAG 2014 Presentation and Whitepaper online: Database I/O

Hi, my #DOAG2014 presentation and whitepaper are online now! “Oracle Core für Einsteiger: Datenbank I/O” Presentation: http://www.performing-databases.com/uploads/media/OracleCoreDatabaseIO-Klier-2014.pdf Whitepaper: http://www.performing-databases.com/uploads/media/Klier-Database-IO.pdf Thank you all for attending! Regards Martin Klier […]

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Performance is rarely an accident (Deutsch)

Some time ago, I saw a great presentation of Cary Millsap: „Thinking clearly about performance”. It was obviously relevant for our internal developers, so he unhesistantly granted me permission to reproduce some of his ideas for us. Cary, thank you very much! Here you can see, what I made out of the topic, mostly for […]

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Oracle 12c InMemory – don’t stop thinking about performance

Oracle has released its new database version 12.1.0.2 that includes the famous in-memory column store. InMemory option  promises a big advantage for OLAP-like work loads by keeping table contents in a columnar in-memory structure. InMemory is not new, they did that for decades, but the interesting part is “columnar”. There’s much writing about that on […]

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