Archive for November, 2012

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!


By Martin Klier in Community,DOAG,Oracle  .::. Read Comments (2)

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!


By Martin Klier in Community,DOAG,Oracle  .::. (Add your comment)

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