How often do you think about the reasons why your favorite RDBMS sucks? Last few months I was doing this quite often and yes, my favorite RDBMS is MySQL. The reason why I was thinking so because one of my recent tasks at Scribd was fixing scalability problems in documents browsing.

The problem with browsing was pretty simple to describe and as hard to fix - we have large data set which consists of a few tables with many fields with really bad selectivity (flag fields like is_deleted, is_private, etc; file_type, language_id , category_id and others). As the result of this situation it becomes really hard (if possible at all) to display documents lists like “most popular 1-10 pages PDF documents in Italian language from the category “Business” (of course, non-deleted, …

The title of MySQL’s website states that they are the world’s most popular open-source database. This is false; MySQL is not an open-source database. That assertion is a fact, not an opinion.

MySQL is Free Software, licensed under the GNU GPL. People frequently use the two phrases “Free Software” and “Open Source Software” as synonyms, but there are very large, very important differences.

The difference between Free and Open Source

Open Source is much more of a development methodology than a philosophical standpoint. The first thing on the Open Source Initiative’s website is this introduction:

Open source is a development method for software that harnesses the power of distributed peer review and transparency of …

Note: these are live notes. It was a great talk, I’d rate it as excellent (and I’m not just saying that because Josh and I work in the same group at Sun). I’ll have to also comment on his thoughts and talk, in due time. MySQL, as an open source project, has a lot to learn.

Ten Ways to Destroy Your Community
A How-To Guide
Josh Berkus, Community Guy

Part 1: The Evil of Communities

• you may attract and will be unable to get rid off a community
• they mess up your marketing plans, because the community goes out and does its own marketing and PR and distributes your software in places you didn’t expect to
• they also mess up your product plans, because they contribute to code and features to your project, with unexpected innovation!
• communities are never …

It’s been a while since I had chance to work on Informeer as my itch was one of multi-user web based password management (AuthStor). Oh and moving house.

Now that things are settling down again (Servers back up and running) I decided to take a break from AuthStor and focus on something new – Informeer.

The concept is simple, Centralised Notification.

I am forever configuring notifications from several sources, be it backup alerts, host monitoring notification and even simple applications that send mail via SMTP. When living in a world of change, both software and business, having to visit every application to change an e-mail address or add a new user to a notification schedule can be quite time consuming. Add to that the effort of having to modify firewalls, SMTP servers and XMPP …

Inspired by the Rail Spikes:

bash-3.2$ history 1000 | awk '{a[$2]++}END{for(i in a){print a[i] " " i}}' | sort -rn | head

228 cd

167 git

10 ssh

10 DEPLOY=production

6 sudo

6 pwd

6 ./script/import_views.rb

5 rm

4 rake

4 mv

bash-3.2$

Really interesting stats, I’d never guess that git is used more than ssh on my desktop (I’m a remote worker and mysql consultant so I ssh really often).

I?ve already taken a look at MySQL?s changing business model and the potential business drivers behind the company considering introducing new functionality under to Enterprise customers only. One area that I didn?t dive into was the impact on the company?s development model.

This, in fact, was the focus of Jeremy Cole?s initial take on the news as well as a significant response from Marten Mickos. ?MySQL will start offering some features (specifically ones related to online backups) only in MySQL Enterprise,? explained Jeremy.

?As I?ve discussed before, the …

Hello my dear readers.

Today I have a question for all of you. What platforms (32bit or 64 bit) do you use for your servers with more than 4Gb RAM? I’m asking because recently we‘ve hit few really weird bugs in Linux kernels 2.6.18 to 2.6.22 and all those bugs were PAE-related. Now I’d really love to move all machines to 64-bit, but I’m in doubt because we don’t know too much about Rails stack (ruby, mongrel, haproxy) on 64-bit platforms (all our DB boxes are 64-bit of course).

So, please drop me a line if you have any experience (negative or positive) with Rails platform on 64-bit machines. I’d really appreciate your help.

Even though I didn’t go to MySQL conf this year (really sad about this), this week is gonna be most active in the community so I decided to do some community stuff too Today I’ve released version 0.3 of our innodb recovery toolkit. Now it became much faster, stable and accurate. At this moment it is possible to recover almost any table from corrupted/deleted tablespace without so much effort as it was before. Here is a short changes list (since 0.1 announced here):

• More MySQL data types added: DECIMAL (both old and new), DATE, TIME
• CHAR data type handling improved in table definitions generator
• Indexes filtering added to page_parser
• 64-bit stat() support added to all tools
• Linux has no isnumber() function so we define our own …

I am happy to announce the release of mylvmbackup version 0.8. mylvmbackup is a tool for quickly creating backups of a MySQL server's data files. To perform a backup, mylvmbackup obtains a read lock on all tables and flushes all server caches to disk, makes an LVM snapshot of the volume containing the MySQL data directory, and unlocks the tables again. The snapshot process takes only a small amount of time. When it is done, the server can continue normal operations, while the actual file backup proceeds.

Below is the list of changes since version 0.6. You may wonder what happened to version 0.7 - it had a rather short life cycle as I was informed about a bug that I fixed quickly before I made a wider release announcement of 0.7.

• Fixed a bug in the InnoDB recovery function: the second mysqld process …

A bit late in the game, but maybe somebody would be interested in working on this proposed project of mine:

PlanetMySQL currently is merely an aggregator of submitted RSS feeds, with some functionality for filtering content to keep the discussion on topic. Due to its high volume of posts, many gems get "lost in the noise" and are hard to retrieve.

We'd like to expand the functionality of PlanetMySQL significantly to provide more possibilities for community participation and interaction. For this project, we are looking for a talented PHP hacker to set up a site that provides the current functionality and more:

• Voting on articles/blog postings: it must be possible for logged in users to cast a vote on articles, similar to the …