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AllThingsOracle - Dynamic Sampling (III) Part I

Just a short note that the third installment's first part of the series on Dynamic Sampling has been published on

You can read there about how Dynamic Sampling deals with real-life data patterns, what about rare values and how indexes might help in such cases.

All Things Oracle Webinar

Thanks to everyone who attended my webinar sponsored by Red Gate and All Things Oracle. My topic was "How to Gather SQL Resource Consumption Metrics in Oracle". The webinar recording has been posted at AllThingsOracle as of May 9 but I thought I'd also make the materials available here for anyone interested. In the zip file, you'll find a PDF of the presentation slides, several example reports (ASH, AWR, SQL Monitor) as well as several scripts I used and a text file containing all the demo queries and output.

Webinar Recording

So to wrap this up, the webinar recording (this time hosted on YouTube, the recording available from the webinar archive is hosted somewhere else) along with the webinar material for download is now officially available on

I suggest that if you still have any questions regarding this webinar then you can comment on the post over there and I'll try to address them.

If you interested in more stuff like that, then stay tuned as there are more of them planned covering many of the aspects that I deliberately left out or mentioned only briefly in this basic introduction.

Webinar Material

Thanks everyone who attended yesterday's webinar at

I hope the technical difficulties with my new mic (which of course work flawlessly during several test runs) weren't too severe so that you could still understand what I said.

As usual when I do presentations in English it took me far too long so probably some of you missed the end of the session. If you did you may want to check the webinar recording once available at the webinar archive at, because we had a very good and extensive Q+A session with excellent questions asked.

Thanks again to and James Murtagh for hosting the event.

Friendly Reminder - Free Webinar

This is just a friendly reminder that tomorrow my free Webinar on Cost-Based Optimizer Basics will take place at

(Virtual) Public Appearances - Free Webinars

I'll be presenting at two upcoming webinars:

1. "Oracle Cost-Based Optimizer Basics" hosted by on Wednesday, 11th April 2012 16:00 (UK Time).

In this session I'll explain the key concepts that influence the decisions of the Oracle Cost-Based Optimizer most. If you want to understand the key concepts about how to write efficient queries and why the optimizer sometimes might not come up with a reasonable execution plan, then this session is for you.

Note that the webinar is free and registrants will receive a recording afterwards. Here is the link to the official landing page. Thanks to for hosting this session.

Here is an abstract of the session:

Just a short note that as already announced last week the second part of the post on how to control Dynamic Sampling activity has been published on

You can read there about the (not so much known) DYNAMIC_SAMPLING_EST_CDN hint, the new Dynamic Sampling auto adjustment feature introduced in release 11.2 and other interesting details.

This is just a short note that the next part of my Dynamic Sampling series has been posted on

This time I highlight how to configure Dynamic Sampling - the first part focusing on the available session/statement levels. The next part will be posted soon and explains some other important concepts regarding Dynamic Sampling behaviour.

Unfortunately these topics are not covered very well by the official documentation. In fact the best coverage used to be in the documentation of the initial release that included Dynamic Sampling (9iR2). You can find the link to that old documentation version in the article over there.

This is just a short notice that the second part of the introduction to Dynamic Sampling has been posted on