We'll soon have our last MySQL University session for this year, followed by a winter break until the end of January 2010. So far there's only one session scheduled next year, but we'd like to have one session per week, so we need lots more speakers!

Anyone who has something technical to say about MySQL qualifies as a speaker. MySQL University sessions take place on Thursday afternoons European time, and normally have between 20 and 30 attendees, but quite a lot of people listen to the recordings when the live session time isn't convenient for them. We're using Dimdim as our conferencing system, so the setup for speakers is very simple: Just grab a headset, start a Flash-enabled browser on either Windows, Mac OS X, Linux, or Solaris, perform a 10-minute test with the MySQL University host, and …

A lot of the time I have found that the only available backup taken from mysqldump contains all databases. This is ok but can be a head ache if you only need to restore one or some of the tables in one database. Below is a good way to restore only that which needs to be restored. I have created three tables in the test database, truncated the third table and now need to restore just that table.

-- Example:

mysql> select database();
+------------+
| database() |
+------------+
| test |
+------------+
1 row in set (0.00 sec)

mysql> show tables;
+----------------+
| Tables_in_test |
+----------------+
| tbl1 |
| tbl2 |
| tbl3 |
+----------------+
3 rows in set (0.00 sec)

mysql> select min(anum), max(anum) from test.tbl1;
…

A few weeks ago I wrote about a student group who will be working with the Drizzle community to build a new database client tool. While the tool will be the primary replacement for the Drizzle client tool, we hope it will be generic (using the Python DB API) so it will work with others like MySQL and PostgreSQL. We’ve had a number of great discussions, including a session at OpenSQL camp last weekend. I wanted to toss out a few ideas of how such a tool could be structured to allow for maximum extensibility.

One possibility is to borrow from typical Unix shells and DSP processing systems where you have a number of modules with I/O interfaces and data exchange formats between each module. Each module provides a specific signature so you know what other modules it can plug into. Here is a simple example:

I attended the Bay Area Startup Weekend in Mountain View this previous week-end. This was the first such event I attended and it was an amazing experience – so I thought I’d share it.

The idea behind the event was that a bunch of folks would show up, some of them would pitch ideas for new startups and the others would join them if they liked the idea and/or had the necessary skills to build it. The goal was to build a working prototype over the course of the week-end.

This seemed like an impossible task to me – not the part where you build a prototype but the idea that random people could come together and actually form a startup. And on talking to one of the organizers, he confirmed that the goal was really to form a community, help people get to know each other – sometimes the team does gel and a successful startup is formed.

Nevertheless, there were …

No I did NOT post the following comment

This is ridiculous. You didn't test MySQL, you tested a failing DNS lookup on authentication.

resulting in the follow up post :

My previous post Redis, Memcache, Tokyp Tyrant, MySQL comparison had a flaw as pointed out by this comment. The MySQL was taking a huge time for doing a reverse DNS lookup.

But as always ... Everything is just a Freaking dns problem :)

Technorati Tags: dns dnsproblem mysql …

While at MySQL, one of the complaints I used to receive every now and then had to do with MySQL’s performance in the area of UNION’s. I distinctly remember one user group meeting where folks from one government agency told me they couldn’t use UNION at all in their application because the performance was so slow.

Now this isn’t always the case with MySQL, but I’ll admit I have seen bad speed on some UNION queries. And that’s one of the reasons I&rsquRead More...

This Thursday (November 26th, 14:00 UTC), Giuseppe Maxia will present the Spider Storage Engine. This session was originally scheduled for October 15th but had to be postponed for technical reasons.

Here's from the abstract: Everybody needs sharding. Which is not easy to maintain. Being tied to the application layer, sharding is hard to export and to interact with. The Spider storage engine, a plugin for MySQL 5.1 and later, solves the problem in a transparent way. It is an extension of partitioning. Using this engine, the user can deal transparently with multiple backends in the server layer. This means that the data is accessible from any application without code changes. This lecture …

A number of people have recently raised the issue of the threat that cloud computing poses to the monetization of open source by specialist vendors, including Savio Rodrigues, Matt Asay, and Mike Hogan.

I believe that cloud computing provides an opportunity for open source specialists, but agree that cloud services based on open source code could potentially eat into the business opportunities for open source specialists since the cloud providers have no …

My previous post Redis, Memcache, Tokyp Tyrant, MySQL comparison had a flaw as pointed out by this comment. The MySQL was taking a huge time for doing a reverse DNS lookup.

I turned on the skip-name-resolve parameter in the my.cnf and the Throughput of MySQL grew considerably, almost more than double.

read more

I had an interesting discussion with 2 colleagues about the possible interest of putting the swap space of a system on a SSD.

If I consider the gain in latency that an SSD brings versus a capacity disk - in the region of 100x - the solution seems obvious. Swapping - or more precisely paging - must be much faster/ with an SSD. Since RAM is expensive versus SSD, I could even be tempted to design a system with a small amount of RAM and a large amount of swap space on SSDs. In other words, I can ask myself if trying to prevent my system to page is still a good fight?

Let's try to shed some light on these questions.

Paging takes place when my system runs out of RAM because more processes are created or because existing processes requires more memory (check this article for details about how to monitor …