In the past life was easy in MySQL. Both CHAR and VARCHAR types meant the same, only being difference in the sense of fixed or dynamic row length used. Trailing spaces were removed in both cases.

With MySQL 5.0 however things changed so now VARCHAR keeps trailing spaces while CHAR columns do not any more. Well in reality CHAR columns are padded to full length with spaces but it is invisible as those trailing spaces are removed upon retrieval. This is something you need to watch both upgrading to MySQL 5.0 as well as designing your applications - you should keep into account if you mind trailing spaces stored choosing VARCHAR vs CHAR in addition to fixed length vs dynamic level rows and space spent for column size counter.

There is more fun stuff with trailing spaces. When comparison is done trailing spaces are always removed, even if VARCHAR column is used which is pretty counterintuitive. So “a “=”a”=”a ” for all …

MySQL CEO Mårten Mickos received a Nokia Foundation Award for his leadership in advancing open source technology.  The Nokia Foundation was formed in 1995 in Finland to support the scientific development of information and telecommunications technologies. Previous recipients of the annual award include Linus Torvalds, and professor Moncef Gabbouj from the Tampere Uninversity of Technology in Finland.

The telecommunications industry in general and Nokia in particular, have been huge beneficiaries of open source technology, with extensive use of Linux and the MySQL to power …

I started this post a month ago, but after Kaj’s discussion on the same topic at the MySQL Camp I figured it was time to post.

I had dinner with a friend recently (a very smart friend), and our conversation lead him to ask “What’s different with MySQL?”. One of the things I tried to describe was the “Pluggable Storage Engine Architecture” (PSE) potential for the future that I expect will set MySQL apart from all other Open Source and even commercial databases.

Here are some details of the example I tried to provide, given somebody who understands enough of the general principles of RDBMS’s.

Consider the ability that information (intelligent data) is available within a Relational Database via the appropriate tools and language (e.g. SQL) but it is not physically constrained to Tables, Columns …

The internet is a great thing. You can find almost anything and share your ideas with anybody that is willing to listen. Unfortunately, that means that anybody with an pugnacious personality and a keyboard also has a voice.

A couple weeks ago, somebody asked me where I deploy MySQL. I created this post about where I think MySQL's sweet spots are in my organization.

I'm no MySQL expert, I'll admit it. In fact, right at the top of the post I indicate as such:
In my opinion, I'd use MySQL for anything but the most mission critical applications. I'm not saying MySQL can't handle the most mission critical applications, but I'm not comfortable betting my business on MySQL at this point. Sheeri Kritzer decides to put her own disparaging slant on my post and writes …

On a lark tonight I decided to transfer BDB pack_row code to the
Archive engine to see if packing made any difference. I had commented
to Peter about this in my previous post (http://krow.livejournal.com/459263.html).

The results?

-rw-rw---- 1 brian brian 1836836760 Nov 27 00:19 accesslog4.ARZ
-rw-rw---- 1 brian brian 1836810272 Nov 27 02:12 foo.ARZ

Accesslog4 is without packing, foo is with packing.

Not much change at all.

Without compression the difference would be noticeable, but with
compression packing does not make much difference. The additional
memory required in overhead for packing alone makes it a bad idea to
implement for an engine already compressing the data stream.

MySQL does not dictate how an engine stores data. Each of the …

Maybe the last XAMPP release of 2006: XAMPP 1.5.5 for Windows and Linux is out. New in both releases of XAMPP are MySQL (5.0.27), PHP (5.2.0), phpMyAdmin (2.9.1) and a Japanese translation. The Windows version also contains up-to-date versions of: FileZilla FTP Server (0.9.20) and ADOdb (4.93).

And today we have yet another scoop for you: The first and long awaited Intel version of XAMPP for Mac OS X. Also updated with all the recent versions of Apache, PHP, MySQL and Co.

Download XAMPP 1.5.5 here

I normally read Planet MySQL from RSS, but for some reason I ended up on the actual site today in a Web Browser (Epiphany to be exact) and saw this:

And thought, “wow, ugly”. I don’t keep my browser “maximised” because I think it’s a stupid way to work - I often switch between tasks or like to have an editor open while referring to something in a browser (e.g. some tech details of some source module), or monitor IRC or IM. I remembered that Epiphany has an Ad Blocking extension, so in an effort to de-uglify, I enabled it. I now see:

Hrrm… much better. Notice how the links on the left to the most active are actually useful now (I can read them).

Note that this isn’t a rant on adverts on web sites - I can handle them (the google ones which aren’t obtrusive) - I’m against the uglyweb.

The inaugural MySQL Community podcast is up at:

http://technocation.org/index.php?option=com_content&task=view&id=16

Let me know what you think — leave a comment, suggestion, question or other feedback. We’re also looking for guest speakers, so if you’re willing to produce a piece, let me know…or just produce one and send it!

Call the comment line at +1 617-674-2369

Or use Odeo to leave a voice mail through your computer:
http://odeo.com/sendmeamessage/Sheeri

Or leave a message at the Technocation forums:

http://tinyurl.com/sc6qw

Or send an e-mail to podcast@sheeri.com

The other night I was thinking about MySQL cluster and whether or not a high speed interconnect would be worth the investment. Doing some research lead me to the conclusion that ethernet latency isn't discussed very often except in niche mailing list threads. I had to do a lot of research to find even a basic discussion of the problem (Note. If you have any good resources on the subject please add a comment.)

In order to help other developers avoid mistakes I've made in the past I figure a good blog post on the subject was in order.

What's ethernet latency? When you send a packet to a remote machine over gigabit ethernet it's not just instant. There's overhead involved in sending the packet back and worth. The data has to go from user space into the kernel, out the network interface, onto a switch, and then back up the kernel and into userland …

Innochecksum is a small undocumented (at least in the manual) utility that verifies the checksum of ibdata file pages. I stumbled across it the other day while wandering through the source tree. It has a small bug that prevents it from being able to check files larger than 4G. This patch fixes it in linux. Someone that knows more about large file support in different OSs please comment on the patch.

It lives in the extras folder in the MySQL source. Here is the credits comment:

/*
InnoDB offline file checksum utility. 85% of the code in this file
was taken wholesale fron the InnoDB codebase.

The final 15% was originally written by Mark Smith of Danga
Interactive, Inc.

Published with a permission.
*/

I think as a community we need to make sure that tools like this are kept in the forge and actively …