Archive for the 'DOAG' Category

Oracle Core für Einsteiger: Datenbank I/O at DOAG 2014

Proud to announce, that DOAG accepted my tech talk “Oracle Core für Einsteiger: Datenbank I/O” for DOAG Conference 2014 in Nuremberg. It’s my next contribution to DOAGs thread aiming at beginners and part-time database people.


The talk will be in German, here comes its abstract:

Oracle Core für Einsteiger: Datenbank I/O
Wir kennen verschiedene I/O-Typen, die die Datenbank benutzt um ihre Aufgaben zu erfüllen. Der Vortrag zeigt anschaulich wie sie sich unterscheiden, und erklärt, welche Vorteile die einzelnen Methoden bieten. Behandelt werden Zugriffe auf Tablespaces, Online/Archived Redo Logs und verschiedene Dateitypen, die mit der Instanz in Verbindung stehen. Eingeschlossen ist eine kurze Wiederholung der jeweiligen Funktion im RDBMS; ebenfalls enthalten ist ein “Crashkurs” zum Automatic Storage Management “ASM”.

Das Ziel des Vortrags ist, Einsteigern das Verständnis von Massenspeicheroperationen näher zu bringen und Hintergrundwissen für ein kompetentes Storage-Sizing zu vermitteln.

I’m also very happy to announce, that my business partner Benedikt Nahlovsky‘s presentation “Kostenlos aber effektiv: Performanceanalyse mit Statspack und SQL*” also was accepted. It’s all about doing professional performance analysis with STATSPACK and SQL* tools.

So Performing Databases is present with two sessions, we really appreciate it!

Looking forward to seeing you all at CCN East, Nuremberg Trade Fair, 18th-20th November 2014!

Stay safe
Martin Klier

DOAG Würzburg: “Resolving child cursor issues resulting in mutex waits”

I feel honored that DOAG asked me once more for being a speaker at an event – this time it’s DOAG Regionalgruppe Würzburg. I will give my (updated) C12LV and Oracle Open World 2012 talk “Resolving child cursor issues resulting in mutex waits” there, supported by my new business Performing Databases GmbH.

My abstract:
In special situations, the Oracle Database generates too many child cursors for particular SQL-IDs. This results in high CPU load on the DB server, coming from heavy mutex access. This is visible as mutex wait events. The lecture will show how this situation arises, how the DBA can try to quick-fix it and how long-term solutions can be found. Additionally, we will have a closer look on the Oracle internal situation: Why does the DB use mutexes here, and how?

Thursday (Donnerstag) 27.03.2014
5 p.m. (17 Uhr)

Würzburger Versicherungs AG
Bahnhofstraße 11
97070 Würzburg

The presentation will be available after the talk at and on the DOAG online-resource page.

DOAG Database Conference Düsseldorf: “YOUR machine and MY database” was accepted

DOAG just informed me that my talk, “YOUR machine and MY database – a performing relationship!?” was accpeted for DOAG Database Conference Düsseldorf. Last year, the first Database Conference at Düsseldorf was a great success, I enjoyed it very much. I’m glad to be part of the speaker’s corps this year.

Hope to see you there!

June 3rd, 2014
Van der Valk Airport Hotel





Oracle Datenbank Architektur – nicht nur für Einsteiger (DOAG Konferenz 2013)

Talk at DOAG 2013

Thanks everybody for attending my talk “Oracle Datenbank Architektur – nicht nur für Einsteiger” at DOAG Conference 2013. It was a great feeling to have a packed room there. As promised, here comes my presentation and whitepaper (both in German).


Feedback is always appreciated!

DOAG Presentation: Oracle Standard Edition RAC

Wednesday last week, I had a presentation for my regional Oracle Users Group (DOAG Regio Nürnberg). The month before I was asked to display the difference between Enterprise Edition and Standard Edition RACs.

Here comes the presentation (German), for questions and suggestions just let me know.

Stay highly available
Martin Klier

DOAG Konferenz 2013: “Oracle Architektur – nicht nur für Einsteiger”





After speaking about mutex waits last year, this time DOAG accepted my lecture “Oracle Architektur – nicht nur für Einsteiger” about Oracle Database basic architecture for this year’s DOAG Konferenz 2013 in Nürnberg. It will be the first lesson in a brand-new stream of the conference: The so-called “Einsteigerpaket” (beginners package) allows seeing a full stream of introductory talks by only purchasing a one-day ticket for the last day (thursday).

“Oracle Architektur – nicht nur für Einsteiger” will cover basic but important concepts of the Oracle RDBMS: How it makes ACID happen, what are Redo Logs, Undo Records, Before Images, how is locking done, and where not, and why all of those old day’s features allowed Oracle to introduce sophisticated stuff like RAC, Dataguard and Flashback without breaking bones.

Nuts and bolts is the topic, but on a level every IT technican should understand. Hope to see you there: 21.11.2013, 0900h, Room 19

Direct link to the session:

Here the link to the papers and a photo from the session.

Oracle Real World Performance Tour 2014 with Tom Kyte and friends in München (Munich)

The German Oracle User Group (DOAG Deutsche Oracle Anwendergruppe) announced Munich as a location of the Real World Performance Tour 2014 with

  • Tom Kyte, Senior Technical Architect ORACLE Server Technology Division, ORACLE Vice President
  • Graham Wood, Architect Server Technologies
  • Andrew Holdsworth, Senior Director Real World Performance Server Technologies

Location: Munich (Details coming soon)
Date: February 19th 2014
Time: 9am – 5pm
Cost: EUR 130,- (Early Bird)

Link to the DOAG event page:

Looking forward to meeting you there!
Martin Klier


DOAG Webinar: ORACLE Datenbank Architektur – nicht nur für Einsteiger (German Language)

On Friday, 08/03/2013, I’ll present an online lecture about Oracle Architecture for the DOAG (Deutsche Oracle Anwendergruppe, German Oracle User’s Group) and the DOAG SIG Database.





The lesson will contain (excerpt from TOC):

  • Oracle Datenbank-Architektur
    • Verbindung, Namespace(s) und Abschottung
    • Instanz und Datenbank
    • Alles Blöcke, oder was?
    • Redo, Undo und was man damit macht
  • Stets das Ziel: „Das Konzept dahinter“ verstehen
  • Primär für Einsteiger = Vertiefung für Erfahrene


It’s free for members, so I hope to welcome you there.
Martin Klier

Here comes the presentation: Oracle Datenbank Architektur – nicht nur für Einsteiger
Thank you very much for attending!!

Oracle: DOAG Konferenz 2012 presentation – Child cursors / Mutex Waits


“Resolving Child Cursor Issues Resulting in Mutex Waits”: Here are my presentation and the white paper about child cursor related mutex waits. The white paper is also available as an article in the IOUG SELECT Journal 3rd Quarter 2012 (Vol. 19, Number 3).

Thanks a lot to all attendees – it was great fun to speak there and to get this overwhelming feedback – to hear “best talk so far” multiple times on a third day is really awesome.Thank you very much!


Oracle: DOAG Konferenz 2012 – Look at’s

Hi there,

as usual, here are my personal notes from DOAG Konferenz 2012 (annual conference of the German Oracle User’s Group). I was there for two days, not three, on account of workload. But it was really good there, and again the event was a great mixture of technology and people/networking.

Ok, here’s the list. Look at:

  • V$SQL_CS_SELECTIVITY, V$SQL_CS_STATISTICS and V$SQL_CS_HISTOGRAM to see a summary how often we are using child cursors
  • the BIND_AWARE hint and its opposite (starting with
  • Adaptive Cursor Sharing works with up to 8 bind variables
  • There will be Cardinality Feedback for Join Cardinalities in Oracle Database 12c (Christian Antognini)
  • SQL reoptimization in 12c (V$SQL.IS_REOPTIMIZABLE), a new term for Cardinality Feedback
  • dbms_xplan format=’all_dyn_plan’ to display 12c dynamic plans (Keyword: Inflection point)
  • Cloning pluggable databases within a container DB is only possible with “open read only” of the source, so what about live cloning?

Yeah, a short list this year, but I did a lot of technical testing stuff there and thus, forgot to write down the one or other thing.

Another compliment to the DOAG staff: Inviting Sascha Lobo for a keynote was a great idea, and also to make the boring usual, ever-skipped Q&A session really fun this year. Carry on!


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