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RAM is the new disk – and how to measure its performance – Part 3 – CPU Instructions & Cycles

If you haven’t read the previous parts of this series yet, here are the links: [ Part 1 | Part 2 ].

A Refresher

In the first part of this series I said that RAM access is the slow component of a modern in-memory database engine and for performance you’d want to reduce RAM access as much as possible. Reduced memory traffic thanks to the new columnar data formats is the most important enabler for the awesome In-Memory processing performance and SIMD is just icing on the cake.

My New Youtube Channel

I have created a new youtube channel – and have uploaded some videos there already! Bookmark & Subscribe here:

More stuff is coming over the next weeks & months :-)


NB! Dates updated: After a 1.5 year break, this year’s only Advanced Oracle Troubleshooting training class (updated with Oracle 12c content) takes place on 14-18 December 2015 and 11-15 January 2016 (I had to reschedule the start from November to December). So sign up now if you want to learn new cool stuff!

Which version of Oracle Linux should I pick for Oracle server product installations?

linux-tuxOracle certifies many of their latest products for installation on Oracle Linux 6 and 7, so I guess the obvious question is, which should you pick?

I tend to have a dual approach to this. I always use the latest versions of everything for my play kit, but I tend to be a little conservative for production deployments, preferring to use the OS version the product was developed against. I’ve noticed Oracle Cloud and some VM templates are still using Oracle Linux 6, which makes me think Oracle are being a little conservative too.

Fedora 23 and Oracle 11gR2/12cR1

A few months ago I mentioned doing some Fedora 22 installations. At the time I did some pre-emptive installations on the Alpha release of Fedora 23 also.

Now the final release of Fedora 23 is out, I’ve run through the articles again to make sure things are all ship-shape.

Little things worth knowing: automatic generation of extended statistics in 12c

When you are migrating to Oracle 12c I hope you might this post useful. I came across this feature when researching what’s new with Oracle 12c (and yes I still find lots of new ones I haven’t noticed before). This one is a bit hidden away in section Automatic Column Group Detection of the 12c New Features Guide. And it’s a lot more complex than I first thought! In this first post I’ll try and show the generation of extended statistics in 12c. I am planning on another post to explain how the rest of the adaptive optimisations that are new with 12c fit into the picture.

What is the motivation?

How the log writer and foreground processes work together on commit.

(warning: this is a rather detailed technical post on the internal working of the Oracle database’s commit interactions between the committing foreground processes and the log writer)

After the Trivadis Performance days I was chatting to Jonathan Lewis. I presented my Profiling the log writer and database writer presentation, in which I state the foreground (user/server) process looks at the commit SCN in order to determine if its logbuffer contents are written to disk by the logwriter(s). Jonathan suggested looking deeper into this matter, because looking at the commit SCN might not the way it truly works.

Fedora 22/23 and Oracle 11gR2/12cR1

linux-tuxAs always, installations of Oracle server products on Fedora are not a great idea, as explained here.

I was reading some stuff about the Fedora 23 Alpha and realised Fedora 22 had passed me by. Not sure how I missed that. :)

Anyway, I did a run through of the usual play stuff.

Web Pages Not Databases – Part 2: Fail2ban, Apache, IP Addresses, Linux, SELinux

August 23, 2015 (Modified August 31, 2015, September 14, 2015) (Back to the Previous Article in this Series) I started using Linux in 1999, specifically Red Hat Linux 6.0, and I recall upgrading to Red Hat Linux 6.1 after downloading the files over a 56k modem – the good old days.  I was a little […]

Installing the Oracle database in docker

This blogpost is about how to install and run the Oracle database in docker. Please mind this is not an officially supported virtualisation platform for the Oracle database. This is a proof of concept setup.

Linux host setup.
In my setup, I used a linux host, freshly installed with Oracle Linux 6.7, which is going to be used as docker server. Please mind you need to leave diskspace (or a disk device) unused for the commonly documented docker setup with the btrfs driver. The root filesystem is using a ext4 filesystem by default. For the proof of concept setup, a 20G diskspace for the Operating system only is enough. I used the minimal linux installation.

The first step is to add a disk, or use a partition and format it with btrfs and mount it:

Preparing a Oracle Linux for a Vagrant box

This post is an overview of an installation and configuration process of the Oracle Linux, which will be used as a machine “box” for Vagrant software using a Virtual Box platform.

Post itself is divided into two parts:

  1. Oracle Linux installation (points 1 to 12)
  2. Vagrant box configuration (points 13 to 16)

Part 1 – Oracle Linux installation


1. Create a new Virtual Machine - machine name will be used later to create Vagrant box