A customer of ours had an interesting problem regarding a query that was taking too long, around 55s. Looking at the query with the query profiler we found that it was spending most of its time in the "statistics" phase. Now the query was pretty complex, it contained nearly 20 tables with INNER JOINs, LEFT JOINs and even some subqueries. However the tables were small and fetching all the data shouldn't have taken the 55 seconds the query was taking. The problem was that the optimiser was spending too much time evaluating and finding the optimal execution plan.

There are two options in MySQL with which you can control the optimiser's behaviour a bit. The first one is optimizer_prune_level. The pruner discards non-optimal execution plans early without evaluating them fully. It is turned on by default and is not recommended to turn off unless there's a really good reason. For testing purposes we turned the pruner off for this query, but …

Installing Cherokee With PHP5 And MySQL Support On Ubuntu 11.04

Cherokee is a very fast, flexible and easy to configure Web Server. It supports the widespread technologies nowadays: FastCGI, SCGI, PHP, CGI, TLS and SSL encrypted connections, virtual hosts, authentication, on the fly encoding, load balancing, Apache compatible log files, and much more. This tutorial shows how you can install Cherokee on an Ubuntu 11.04 server with PHP5 support (through FastCGI) and MySQL support.

(Fractal) Tree Frog

Fractal Tree™ indexes are green. They have the potential to be greener still. Here’s why:

Remarkably, data centers consume 1-3 percent of all the US electricity. A majority of this power is used to drive servers and storage systems. Significant energy savings remain on the table.

Here’s why Fractal Tree indexing enables more energy-efficient storage: Data centers typically use many small-capacity disks rather than a few large-capacity disks. Why? One reason is to harness more spindles to obtain more I/Os per second. In some high-performance applications, users go so far as to employ techniques such as “ …

Looking to join Oracle’s MySQL team? Our training team is hiring a MySQL curriculum developer!

You can find the job description and apply here.

While the job description refers to Dublin as location, applicants can actually be based pretty much anywhere. Your curriculum development/design experience, database & MySQL expertise and proficiency in English will matter most than location.

If you have experience in designing and developing training courses, and are passionate about databases in general and MySQL in particular, we look forward to hearing from you!

Looking to join Oracle’s MySQL team? Our training team is hiring a MySQL curriculum developer!

You can find the job description and apply here.

While the job description refers to Dublin as location, applicants can actually be based pretty much anywhere. Your curriculum development/design experience, database & MySQL expertise and proficiency in English will matter most than location.

If you have experience in designing and developing training courses, and are passionate about databases in general and MySQL in particular, we look forward to hearing from you!

XKCD (as usual) makes a very good point – this time about password strength, and I reckon it’s something app developers need to consider urgently. Geeks can debate the exact amount of entropy, but that’s not really the issue: insisting on mixed upper/lower and/or non-alpha and/or numerical components to a user password does not really improve security, and definitely makes life more difficult for users.

So basically, the functions that do a “is this a strong password” should seriously reconsider their approach, particularly if they’re used to have the app decide whether to accept the password as “good enough” at all.

Update: Jeff Preshing has written an xkcd password generator. Users probably should choose their own four …

So, vacation is over and I was in luck: Already during first week I had ample time to finally put Galera replication to the test. It was a great experience: I learned a lot, and eventually got the great results I was hoping to see.

Again I've started by just running the standard Sysbench oltp read-write test. Since this is a commonly used benchmark, it produces numbers that are comparable with others running the same benchmarks. Including, as it happens, Galera developers themselves.

These tests were run on an 8 core server with 32 GB of RAM and the disk on some EMC device with a 2,5GB write cache.

read more

The past few years of MySQL conferences...

Every year since Oracle's acquisition of MySQL in 2009, there's been some uncertainty around the annual MySQL conference, which used to be co-organized by MySQL AB (in charge of content) and O'Reilly (conference logistics). As my career unfolded during those years, I've seen relatively close how the conferences of 2010 and 2011 happened. As there's been a lot of re-structuring in the community around various forks and new employers, I've felt that the annual conference was the one thing that kept us together, the one common forum where everyone would meet. For this reason I have been personally very engaged (as have many others) in helping O'Reilly get through the conferences of 2010 and 2011 and I'm very grateful to Tim, Gina and the rest of the O'Reilly team that they have provided us with this forum and gravitation point for the past two years.

During this years conference it was openly …

With the fast growth of virtualized data centers, and companies like Google, Amazon and Facebook, it's easy to forget how much is built on open-source components, aka commodity software.  In a very real way open-source has enabled the huge explosion of commodity hardware, the fast growth of the internet itself, and now the further acceleration through cloud services, cloud infrastructure, and virtualization of data centers.

Your typical internet stack and application now stands on the shoulders of tens of thousands of open source developers and projects.  Let's look at a few of them.

1. Operating System - Linux

The commodity hardware craze would never have happened without the help of an open-source operating system to run on it.  Linux is an old story now, nonetheless everything else stands on it's shoulders.

2. Multi-purpose Webserver - Apache

As of July …

I am reading the announcement about the Percona MySQL event in place of the O’Reilly.
What I see and what I feel is that the whole MySQL community, including Oracle, Percona, SkySQL,MariaDB and any other company doing business with MySQL have lost a good opportunity (so far).

For many years we have seen and hear comments about having this event more focus on users, and less bound to a single company. Now what? We will have a single company promoting the event. I don’t care if it is done by Percona instead Oracle or SkySQL, actually I like all of them and I knew personally almost all of them as well.

What I care/like is to have this event NOT limited to a single company.

There was an attempt to have it organized in a different way (see Giuseppe and …