Without a doubt, it was the statistic that surprised me the most in the surveys I did at MySQL. In short, MySQL is huge on the Windows platform. In terms of downloads, no other platform comes close to Windows, even when you total up all the Linux variants. And when I specifically asked on our surveys what production O/S platform is used for MySQL, Windows was #2 for MySQL Enterprise customers, with RHEL being number one, and (very surprising!) #1 for Community users. Moreover, when asked what...

Last week I was struggling to find an easy way to simulate a troubled Data Node (ndbd process) using MySQL Cluster. It's as simple as pancackes: using the kill command!

To freeze a process you just need to kill the process using the SIGSTOP signal. To let the processes continue, use SIGCONT. Here's an example shell script showing how you would use these two signals on a data node:

# 2010-05-03 08:11:46 [ndbd] INFO     -- Angel pid: 542 ndb pid: 543
 NDBDPID=`grep 'Angel pid' ndb_3_out.log | tail -n1 | awk '{ print $11 }'`
 kill -STOP $NDBDPID
 sleep 10
 kill -CONT $NDBDPID

I'm using the out-log because the file ndb_3.pid contains only the PID of the Angel process. The sleep command is …

Just in case you haven’t noticed, Ubuntu 10.04 “Lucid Lynx” has arrived. I upgraded my personal box over the weekend, and am happy to report that things went pretty flawlessly for me. So I’m now a happy lucid user.

What’s more important for the ever-growing cluster community is the fact that this LTS release comes with built-in support for the Pacemaker cluster stack — and indeed, it’s the first commercially-supported distribution that comes with support for both the Heartbeat and the Corosync cluster messaging layer. And it’s easy, too!

Here’s how I install the Pacemaker stack with Heartbeat (which I prefer) on an Ubuntu box:

aptitude …

Cassandra is one of the most interesting NoSQL platforms at the moment.  And by most interesting what I really mean is the most clearly justifiable.  Some NoSQL platforms offer new data models, improved query interfaces and/or good single node performance through relaxed consistency models.  As a database guy however, the justification for throwing out the RDBMS baby and bathwater is still difficult at this point as NoSQL platforms tend to be highly focused in one aspect of data management, and very immature in all other areas.  Cassandra is somewhat different as it is more mature in a number of key areas (albeit still immature in others).  Areas that can make Cassandra more justifiable for the right project, when compared with a more traditional RDBMS based solution.  This is because Cassandra’s primary capabilities can’t easily be replicated on those …

I will not bother to comment on Monty's keynote (but I did post the text to it so you can make up your own mind) and this brings us then back to the Tuesday and Oracle's opening keynote featuring Edward Screven.

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Somebody should teach me how to accept community contributions.
On Friday I looked at the second version of a community contributed patch. I.e. it was since then re-written. It's Bug#20837, and it again is an infrastructure issue that is identical in all our forks.

While looking at the patch, I encountered 7 issues, which I had to report:
Bug#53340, Bug#53341, Bug#53342, Bug#53343, Bug#53344, Bug#53345, Bug#53346.

(I won't go into the details how …

Recently (on April 19, 2010), Monty gave a Google Tech Talk, titled: MariaDB: The Backward Compatible Branch of the MySQL Database Server. The talk is under 47-minutes long, and the video is embedded below. Its a good introduction to what MariaDB has been up to for the last year+, aims, goals, and the future.

The Friday after the official MySQL conference was double booked. In parallel with the storage engine summit, Drizzle Developer Day 2010 was also happening. This event took the form of a hackathon, with free form discussions and hands on coding. I popped in, to experience the energy.

My conclusion both from Brian's keynote and the Developer Day is that:

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MySQL stored procedures are programs that are stored and can be executed on the MySQL server. Using MySQL Stored Procedure you can solve mysql related problem or task easily. Here I’m describing a stored procedure that I used to create some sample data. Read Full Article

Some days ago I was working in a vocabulary game and dictionary. The dictionary contains 1,10,000 words and meanings. I developed a vocabulary game where I had to randomly choose 10 words out of 1,10,000 dataset. Here I’m describing the possible solutions for retrieving 10 random words from 1,10,000…  Read Full Article