on ORDER BY optimization | Domas Mituzas

http://dom.as/2015/07/30/on-order-by-optimization/

An insightful exploration by Domas (Facebook) on how some of the MySQL optimiser’s decision logic is sometimes naive, in this case regarding ORDER BY optimisation.

Quite often, “simple” logic can work better than complex logic as chasing all the corner cases can just make things worse – but sometimes, logic can be too simple.

Everything must be made as simple as possible, but no simpler.
– Albert Einstein / Roger Sessions

Copyright on APIs and header files? | Upstarta

Removal and Deprecation in MySQL 5.7 | MySQL Server Blog

http://mysqlserverteam.com/removal-and-deprecation-in-mysql-5-7/ A useful overview of options, syntax and tools that have been deprecated or removed for the upcoming MySQL 5.7 release.

More Cores or Higher Clock Speed?

This is a little quiz (could be a discussion). I know what we tend to prefer (and why), but we’re interested in hearing additional and other opinions! Given the way MySQL/MariaDB is architected, what would you prefer to see in a new server, more cores or higher clock speed? (presuming other factors such as CPU caches and memory access speed are identical). For example, you might have a choice between
  • 2x 2.4GHz 6 core, or
  • 2x 3.0GHz 4 core
which option would you pick for a (dedicated) MySQL/MariaDB server, and why? And, do you regard the “total speed” (N cores * GHz) as relevant in the decision process? If so, when and to what degree?

mysql-cli on Kickstarter

Open Query is supporting the mysql-cli Kickstarter project (for MySQL and MariaDB) by Amjith Ramanujam who already successfully completed a similar tool for PostgreSQL. It is a new MySQL client with Auto-Completion and Syntax Highlighting. From the info provided, it’s Python based, thus portable, and can be installed without root access. Could be a very useful tool. The good old mysql command line client does lack some things, yet a relatively low-level command line client is often useful for remote tasks (as opposed to graphical tools) so we reckon it’s good that this realm gets a bit of attention!

Interactive Online Training for MySQL and MariaDB

Because interactivity with the trainer (our classes are not dry lectures) and discussions are an important and intrinsic part of our teaching approach, we’ve long tracked development of technologies for online training, but previously were not satisfied. High costs of various corporate offerings would negatively impact our pricing, given the relatively small scale use and our purposely small classes. The student system requirements would often be problematic – obviously students use different operating systems (Windows, Mac, Linux) and we cannot prescribe that people use a particular OS. Big Blue Button has long looked like it had the right potential, and it’s now developed to a point where were happy with it. For more tech and practical details, see our Interactive Online Training page. After our successful trial runs, we have the following course modules scheduled in the next few weeks, others to follow soon: The date ranges may appear a tad odd at first, but what we do is run each original day-module across two sessions over two days, in this case noon-3.30pm Sydney time. An online session has three 10 minute breaks. As you can also see the pricing is pretty neat – we can do that since we control the infrastructure and obviously don’t have trainer travel, venue and catering to worry about. No travel hassles for you, either! You should find a quiet spot and try and not get interrupted. All the interactivity, discussion and hands-on work is there as normal, Open Query provides the VMs – and students (and trainer) can access each other’s session, where needed. We’re pretty pleased with the set up. Naturally we can also do custom training in this format – we do still offer on-site training as well. For bookings, or if you’d like more information or have other questions, contact us today!

Exploiting the DRAM rowhammer bug to gain kernel privileges | Project Zero

Open source ‘wasn’t available’ two years ago, says Universal Credit chief | ComputerWorld UK

VMware Integrated OpenStack – Cost Analysis | Technodrone

http://technodrone.blogspot.com.au/2015/02/vmware-integrated-openstack-cost.html Maish Saidel-Keesing writes:
VMware announced last week the launch of VIO and there are a number of things that I think people are missing and should be pointed out.

LKML: Live patching for 3.20

https://lkml.org/lkml/2015/2/9/534 Building on the original kSplice idea and combining the efforts of the work done at Red Hat and SuSE, common infrastructure is now ready to be put into the Linux 3.20 mainline kernel – Red Hat and SuSE have already committed to using this. I still reckon it’s freaky trickery, but heck – it works, and it’s great for server environments that have no redundancy (I prefer to fix that issue!) and can’t afford any downtime.