Working on performance optimization project (not directly MySQL related) we did a test - creating 100 files writing 4K in the random file for some time and when checking the read speed on the files we end up with, compared to just writing the file sequentially and reading it back.

The performance difference was huge - we could read single file at 80MB/sec while fragmented files only deliver about 2MB/sec - this is a massive difference.

The test was done on EXT3 and it looks like it does not do very good job preventing file fragmentation for large amount of growing files.

It would be interesting to see how other filesystems deal with this problem, for example XFS with delayed allocation may be doing better job.

I also would like to repeat the test with MySQL MyISAM tables and see how bad the difference would be for MySQL but I would expect something along those lines.

Interesting enough it should not be …

North Bridge, a leading Venture Capital firm has launched a survey on the Future of Open Source. Results from the survey will be announced at a panel session at InfoWorld's OSBC conference in San Francisco March 25-26. The session is hosted by Michael Skok of North Bridge and panelists include Marten Mickos from MySQL, John Roberts from SugarCRM and Mark Shuttleworth from Canonical among others.... READ MORE

MySQL being acquired by Sun has of course put a lot of focus on the success of MySQL so far, but it is also interesting to think what success will mean as part of Sun too. In this light a recent interview of MÃ¥rten by Business Review Online about the acquisition was inspiring. (As words from MÃ¥rten usually are!)

"It's a marathon, not a sprint," he said. "If a 15-year-old downloads MySQL now, when do we get our money? In about 15 years' time when he is head of IT at a company and he loves MySQL. But in many cases it will happen sooner than that."

"In open source we say fail fast, scale fast. Many web 2.0 ideas will fail, but when Google or Facebook [two of MySQL's biggest customers] get it right they suddenly need to scale like crazy," Mickos said. "Open source is the only model where they can scale fast on exactly the …

You can hack the MySQL server in three ways:

• Changing the server code. This is straightforward. Download the code, and make the changes you need. If you need the change only for a limited period, this is enough. If the change must be persistent, then you should try to make it accepted. The Code Contribution Program may be for you.
• Creating a plugin or a UDF. Using the plugin interface or the UDF API you can extend the server in many ways. UDFs require that you (and the user) be able to compile the additional code. Plugins require compiling code only from the author.
• Mixing the existing hooks. This means being creative bu stretching the intended …

(See this post for background information on MySQL Function of the Day)

Week Two:

• Wednesday, March 12, 2008: ELT()
• Thursday, March 13, 2008: IF()
• Friday, March 14, 2008: REPEAT()
• Monday, March 17, 2008: FLOOR()
• Tuesday, March 18, 2008: DIV()

Week One:

• Wednesday, March 5th, 2008: CHAR_LENGTH()
• Thursday, March 6th, …

If you're serious about MySQL, it doesn't hurt to know the people closely tied to its development and maintenance as well as famous bloggers. Here's my ongoing list of people I consider important:

Peter Zaitsev - MySQL Performance Blog, former head of MySQL AB High Performance Group. His company Percona is available for consulting. He's a co-author of High Performance MySQL 2nd edition (great book).

Baron Schwartz - also know as Xaprb, Baron a co-author of High Performance MySQL 2nd edition and creator of …

I can't say that I look forward to any …

Just as a head’s up to students that are thinking about participating in the Google Summer of Code 2008, and were planning on being affiliated with MySQL. You can - MySQL has just been accepted into the Summer of Code 2008.

We have an ideas page (watch it closely, there will be many changes in the coming weeks), we also have a mailing list (subscribe to it, and discuss with potential mentors), and now, all we want are plenty of students!

This should also be a note, that its a call for mentors. Last year, we had Paul McCullagh and Sheeri Kritzer Cabral, mentor projects from outside MySQL, and it was great. Participation from the …

I posted a simple INFORMATION_SCHEMA query to find largest tables last month and it got a good response. Today I needed little modifications to that query to look into few more aspects of data sizes so here it goes:

Find total number of tables, rows, total data in index size for given MySQL Instance

PLAIN TEXT SQL:

1. mysql> SELECT count(*) TABLES,
2.     ->        concat(round(sum(table_rows)/1000000,2),'M') rows,
3.     ->        concat(round(sum(data_length)/(1024*1024*1024),2),'G') DATA,
4.     ->    concat(round(sum(index_length)/(1024*1024*1024),2),'G') idx,
5.     ->    …

In the past few months I’ve not had to look for a job, they look for me. If your a well qualified MySQL DBA there are many opportunities, I’ve had so many of these offers in the past 12 months I’ve lost count. However a DBA job would not offer the job satisfaction I’m seeking in my career goals now in 2008.

I’ve been able to consider 4 genuine positions in just the past few weeks, and indeed my new employer Primebase Technologies was someone I’d never considered working for, and indeed they had never considered me until a chance lunch meeting less then one month ago.

I did seriously consider working with Paul Vallee and the team at Pythian. Pythian looks for the best people from their respective levels of technology expertise, whether a college graduate or a 2 decade RDBMS veteran. This company has a great work …