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October 2013

OTN Nordic Tour 2013 – Copenhagen

I spent the first two sessions of the DOUG event watching Mike Dietrich presenting on 12c upgrades, pluggable databases and new features. I’ve seen some of his stuff already during the LAOTN Tour (Southern Leg), but his presentations have changed a little since I last saw them. To quote Noons,

“Mike’s talk is superb. No bull, just down to facts…”

I think that sums it up nicely. :)

Exadata: what kind of IO requests has a cell been receiving?

When you are administering an Exadata or more Exadata’s, you probably have multiple databases running on different database or “computing” nodes. In order to understand what kind of IO you are doing, you can look inside the statistics of your database, and look in the data dictionary what that instance or instances (in case of RAC) have been doing. When using Exadata there is a near 100% chance you are using either normal redundancy or high redundancy, of which most people know the impact of the “write amplification” of both normal and high redundancy of ASM (the write statistics in the Oracle data dictionary do not reflect the additional writes needed to satisfy normal (#IO times 2) or high (#IO times 3) redundancy). This means there might be difference in IOs between what you measure or think for your database is doing, and actually is done at the storage level.

OTN Nordic Tour 2013 – Stockholm

I didn’t sleep too well the night before the Stockholm event, so I woke up feeling extremely groggy. I think it was just the combination of excitement and adrenalin you get before starting a tour. I met Lonneke and Sten for breakfast, then headed on to the conference venue.

I watched Lonneke presenting on SOA for the first two sessions of the day. This is completely not my area of expertise, but I learnt a lot in these sessions. I now understand a lot of the buzzwords and a lot of the common pitfalls for the first time ever. I’ll never be a SOA guy, but it’s nice to know a little more, so that I can understand when people are leading me astray. You don’t have to know how to swim to recognise when someone is drowning. :)

Exadata and the passthrough or pushback mode

Exadata gets its performance by letting the storage (the exadata storage server) participate in query processing, which means part of the processing is done as close as possible to where the data is stored. The participation of the storage server in query processing means that a storage grid can massively parallel (depending on the amount of storage servers participating) process a smart scan request.

OTN Nordic Tour 2013

I got up this morning in plenty of time to get to the airport to fly to Sweden to begin the OTN Nordic Tour 2013 tomorrow. I then proceeded to wait and wait and wait for the taxi. Eventually it did arrive, but now the rush hour traffic had started to build up, so time was ticking by and we were standing still for a very long time. I tweeted that I would probably miss my flight and I really believed I would.

After a considerable amount of time, with me trying to ignore the nervous glances of my driver, the traffic opened up, I got to the airport and check-in was empty, as was security. I got through in time to grab a drink on the way to boarding. Phew…

Captain Support and the Windows 8.1 Upgrades

Being the adventurous type of guy he is, Captain Support decided to launch into Windows 8.1 upgrades on his Mom’s and sister-in-law’s laptops. They were identical machines, both running Windows 8 and configured the same. One was local and the other connected to over LogMeIn…

The first thing he noticed about the upgrade is the size of it, approximately 3G. The download and initial install can be done while you’re still using the machine, then comes the inevitable reboot where the real work is done…

The second standout point was the update forced him to him to switch from a local user to a Microsoft Live login. Both Captain Support’s Mom and sister-in-law both use Hotmail/, so this did not present an immediate issue, but it was annoying. Perhaps there is a way to avoid this, but it was not immediately appareent to Captain Support… You can still create local users after the update of course…

Three Things To Do Before Starting Hadoop Project

I spent the last 6 month helping customers design, implement and deploy successful Hadoop systems. Over time, you start seeing patterns. Certain things that if the customer gets right before the project event starts increase the probability that the project will finish successfully and on-time.

Lets assume you already took the most important step – you have an actual use-case or a problem to solve, and you think  Hadoop could be the right technology to use in this case. What now?