I was reading this month’s php|architect. It has a nice article about EAV modeling. I had seen this db structure in other project, but didn’t know that it was called EAV. For those who don’t read php|architect, EAV describes a method of saving a large set of attributes, only some of which apply to an individual entity. Normally you would create a table, with a row for each entity and save each attribute in a column. With EAV you save each attribute as a row.

This makes selecting the data quite tedious. If you can life with some constraints, there is an easier way to do this.

The common way

How php|architect describes it (and how it’s normally described) is to split out the values over different tables for the different data types. The DB structure proposed in php|architect look like:

CREATE TABLE field_names (
    fid INT UNSIGNED PRIMARY KEY …

In the Skoll project, we are trying to build a community-based distributed process to test MySQL. From the users perspective, the Skoll clients connect to the Skoll server and receive instructions to build MySQL in a specific configuration. The Skoll client then compiles MySQL and runs a set of about 750 standard MySQL installation tests. Finally, the client sends a summary of the test results back to the Skoll server. What the users do not see is the big picture. How does the Skoll server model the MySQL configuration space? How does the Skoll server select specific configurations from this space to be tested.

The MySQL's configuration space is large, about 48 million of them. It is impossible and impracticable to test every single configuration for …

I was just reading The Big Mac Dilemma, who asks:

is using a Mac “selling out” from your OSS ideals?

and I’d like to be very unfriendly and answer unequivocally… YES.

Just like anything else non-free, it tempts you with shiny baubles and the promise of making all of your wishes come true. And just like anything else non-free, it shackles you into a sub-standard environment all the while telling you that your computer is now obviously superior. (Mail.app? Really? Oooh.. bouncing icons…)

I’ve been working on Drizzle recently, and in the not-so-terribly-long time we’ve been working together, we’re already having to deal with people from the OSX camp complaining about library dependencies. I can’t ingore them, because like Eric was saying, just about all the developers these days are running either OSX or Ubuntu. However, it …

Someone who should know told me that LinkedIn runs its main application on Oracle. So when I saw the press release about MySQL being their database, I read carefully, and they are not very specific about exactly what MySQL is used for. Depending on how you read it, you could argue that they left open the possibility that the main application database is not MySQL, and the MySQL deal is for something peripheral.

Now, this is nothing but a rotten rumor and I will probably burn in hell for spreading it, but I’d like it to be debunked if it’s false. What is LinkedIn’s main database server? Anyone have the provably correct answer?

PS: I see that LinkedIn is “seeing daily downloads of approximately 200 million.” I didn’t know it was downloadable. I’ve been missing out! Where can I download it?

…

KEY ACCOMPLISHMENTS LAST WEEK

• Fixed Skoll Client to work with the new commands related to Bazaar switch. Running shell commends in Java, esp supporting both Java 1.4 and 5.0, is difficult and brittle.
• Analyzed MySQL runtime data with Weka. Most of the work is in retrieving/preparing the large amount of data efficiently from the database.

KEY TASKS THAT STALLED LAST WEEK

• Still did not collect runtime data with Skoll Client due to Bazaar switch.

KEY CONCERNS

• None

TASKS IN THE UPCOMING WEEK

• Runtime data collection.
• Continue to research tools and methods to analyze runtime information.

As the Product Manager for MySQL Enterprise and the Enterprise Monitor I am constantly being asked questions from our Sales team, prospects, customers, etc. about how our products stack up against competing products. This is tough for a PM because competitive situations change with each new release cycle and ISVs (both free/open and commercial) with agile development practices can deliver new features in very short order. Further, getting into a feature-feature discussion is a no win situation because someone will ALWAYS have more check marks. Also, I tend to be more positive about competing products because a) healthy competition makes us all better and b) my competitors enable more people to use MySQL to build apps that will most likely need MySQL support and c) the best support for MySQL comes under a MySQL Enterprise subscription! With those things in mind you will *never* hear …

Last week I was at OSCON (more on that later) and I was surrounded by a mix of laptops - most of them running Ubuntu or OS X. This caused an internal dilemma I’ve been having for years to resurface: is using a Mac “selling out” from your OSS ideals? I still use a PowerBook and last fall I purchased an iMac (guilt included). Previously I had been running Slackware Linux on a wide range of desktops and laptops (this was since 1995). I switched because I was tired of dealing with all those little pesky hardware compatibility issues, especially on laptops, and I thought the time saved there would be a good tradeoff for new development. Well, I don’t think I can use that excuse anymore. Ubuntu is pretty slick and takes many of those issues away. A few laptop manufacturers are even shipping with Linux now. There is even an argument using OS X for development is more difficult now (try compiling large applications like MySQL or Drizzle). How do you …

Hot on the heels of news that SquareSpace is using Oracle, comes news that LinkedIn is going whole hog with MySQL.

Actually, you could say that LinkedIn is buying into Sun. They are buying the MySQL Enterprise subscription and they'll be running MySQL on Sparc servers and Solaris 10. They've signed up for Sun Professional Services, MySQL Professional Services, and …

Tim O'Reilly talks about the value of data and lock-in READ MORE

Last week I asked for more case studies, and I heard back from a range of companies that recently had significant customer wins. In an effort to spread the good word, here are a few new places that open source is releasing customers from the shackles of proprietary lock-in:

• LinkedIn has selected Sun's MySQL database

...