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Exadata

Drilling Deep Into Exadata Performance with ASH, SQL Monitoring and Exadata Snapper – slides and a hacking session!

The promised hacking session about Exadata performance troubleshooting will happen on Thursday 21st February 9am-11am PST (2 hours). I will show a number of examples and demos where the Exadata Snapper shows what was going on in storage cells when running Smart Scans or just doing IO.

Register here (free stuff!):

Slides:

I will post the scripts on the day of this session.

How to Troubleshoot OEM 12c Cloud Control Auto-Discovery

I was recently involved in an upgrade project to go from 11.2.0.2 to 11.2.0.3 on an Exadata V2. We hit some snags during the upgrade specifically related to OEM 12c Cloud Control. We performed an out-of-place upgrade and OEM 12.1.0.1.0 had some difficulty in dealing with this.

12c Cloud Control is supposed to run a daily check that looks for new targets on each server. When it finds something new, it places this in a queue to wait for admin approval. With a single click, you can promote the newly discovered target to an OEM managed object.

RMOUG – Here I Come

Well, I’ve just finished pushing the last few bits into my suitcase for my trip to the US for the Rocky Mountain User Group Training Days 2013.

It is a few years since I went to the US for pleasure (3 years?) and much longer since I went there on a combined work/pleasure trip – as I HATE going through US immigration.

Storage Indexes vs Database Indexes Part III: Hidden Values (Hide Away)

OK, my holiday to Hawaii is now slowing fading away into distant memory. Time for a new post In my previous post on differences between Exadata Storage Indexes and Database Indexes Part II, I discussed how the clustering of data within the data is an important factor (pun fully intended !!) in the performance and […]

Enkitec Extreme Exadata Expo (E4) 2013 – Call for Papers

Enkitec E4, the only exclusively Exadata-focused conference in the world, is going to be back this this year too! :-)

It will take place on 5-6 August 2013 in Four Seasons Hotel & Resorts in Irving, TX. It will be very hot in Texas then, but the hotel has a really cool pool there (which I intend to be able to use this year – last year I had to spend all my free time working in the hotelroom unfortunately). And they have beer inside too :)

There will be very good speakers showing up this year too (including the keynote speaker who’s awesome, but I can’t say the name yet) and I’ll hang out there too. I think I’ll deliver a live demo / internals hacking session this year (that way I don’t have to spend my night before the conference preparing slides and can focus more on the cool stuff).

Exadata Smart Scan Projection Limitation

Here is an interesting limitation to Exadata Smart Scans - if more than 254 columns from a table (not HCC compressed, more on that in moment) need to be projected, Smart Scans for that particular segment will be disabled and Exadata will fall back to conventional I/O.

New Exadata Prototype

I got a look a new prototype for the next generation Exadata last week while doing some work with a company in Europe. Apparently there is a big push to be environmentally friendly there now and so Oracle is trying to come up with a model that uses less power and is biodegradable. The word on the street is that it won’t be available until after release 2 of the 12c database.

The new model has a few drawbacks though. For one thing, it only lasts a few weeks before you must either replace it or higher some rocket surgeon consultants to come in and tune it. From the early version of the prototype I saw, it does appear to be smaller and more tasty than previous models though.

 

 

Oracle 11.2.0.1 and the ‘kfk: async disk IO’ wait event

Recently I was discussing some IO related waits with some friends. The wait I was discussing was ‘kfk: async disk IO’. This wait was always visible in Oracle version 11.2.0.1 and seems to be gone in version 11.2.0.2 and above. Here is the result of some investigation into that.

First: the wait is not gone with version 11.2.0.2 and above, which is very simple to prove (this is a database version 11.2.0.3):

HOWTO: Viewing XML data in V_$CELL_% storage cell SYS views

Got a small question from Frits if I could help him make some XML data readable in one of the SYS.V_$CELL_% / V$CELL_% views. I have been a bit busy, in between jobs, to try to make some of those XML columns more readable anyway (for myself and others) so…lets have a go at it. …

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Storage Indexes vs Database Indexes Part II: Clustering Factor (Fast Track)

Two posts in two days !! Well, with Christmas just around the corner, I thought I better finish off a couple of blog posts before I get fully immersed in the festive season The Clustering Factor (CF) is the most important index related statistic, with the efficiency of an index performing multi-row range scans very much […]