In MySQL 5.0 mainly error control was improved, such as strict mode was added to change famous MySQL behavior of cutting too large strings, too big numbers and allowing you to use dates such as February 31st.

In one case however reverse change was done - in regards to storage engine initialization. Previously if you start MySQL and Innodb storage engine fails to initialize (ie you resized log file but forgot to delete old ones) MySQL Server simply would not start. In recent MySQL 5.0 series however it will continue loading and simply have Innodb storage engine disabled.

This can cause numerous problems especially if you got use to old behavior and do not check MySQL logs but simply check it is started. It especially hurts if you have only some tables in Innodb so you might not notice part of your application does not function. Also monitoring often monitors MySQL is up and running and will not query all tables are accessible not …

This article explains how to do subtraction in SQL over samples that wrap back to zero when they exceed a boundary.

OK lazy web…. You have to help me out!

I try to monitor every performance metric I can within my cluster. Memcached efficiency, MySQL key buffer efficiency, etc.

One thing I can’t benchmark is the efficiency of the Linux filesystem buffer (buffer cache).

From all the research I have done there’s no way to to see the number of hits or total reads done by the file system cache.

Has anyone solved this problem?

The first XAMPP release of 2007. ;) Updated in all three XAMPP versions: Apache 2.2.4, PHP 5.2.1, PHP 4.4.5, MySQL 5.0.33 and phpMyAdmin 2.9.2.

Get the downloads and more details on the specific XAMPP project page.

In Part 1 of this article series, we looked at how the Falcon transactional storage engine was architected and how it compared to some of the other MySQL storage engines. Part 2 covered how Falcon handles transaction management and concurrency. In this final article in the series, I?ll look at how Falcon manages tables and indexes, and also cover backup/recovery along with migration topics.

The first XAMPP release of 2007. Updated in all three XAMPP versions: Apache 2.2.4, PHP 5.2.1, PHP 4.4.5, MySQL 5.0.33 and phpMyAdmin 2.9.2.

Get the downloads and more details on the specific XAMPP project page.

I always disliked the way PHP handles Objects. There is no way to assign a type to properties. Validators have to be glued against the fields externally and you can't just generate a Object-Description (like WSDL) from a object either.

Usually you have DataObjects like:

/* a plain-old-php-object */

class Employee {
    var $employee_id;

    var $name;
    var $surname;

    var $since;
}

and as a human you immediatly how to use it:

$e = new Employee();

$e->name       = "Jan";
$e->surname    = "Kneschke";
$e->employeenr = 123;
$e->since      = mktime(0, 0, 0, 1, 1, 2005);

But you can also have a bad day and write something like:

$e->unknown = "value";
$e->since = "Monday";

The property unknown gets created automaticly in the object and since gets a invalid value. If you take a look at ActiveRecord in Rails you see how proper types …

I did some comparison of ZFS vs XFS last week to review the current state of the art in filesystems.

Long story short. XFS is still the reigning champion (at least on Linux). XFS beats out most filesystem benchmarks across the board. Reiser does well on directories with lots of small files but not enough to justify not using XFS.

Reiser FS is out of the picture honestly. First, it just doesn't perform very well. Second, Hans Reiser is probably going to prison for murdering his wife and is selling the company to pay off his legal costs.

ZFS would have a shot on …

I did some comparison of ZFS vs XFS last week to review the current state of the art in filesystems.

Long story short. XFS is still the reigning champion (at least on Linux). XFS beats out most filesystem benchmarks across the board. Reiser does well on directories with lots of small files but not enough to justify not using XFS.

Reiser FS is out of the picture honestly. First, it just doesn’t perform very well. Second, Hans Reiser is probably going to prison for murdering his wife and is selling the company to pay off his legal costs.

ZFS would have a shot on …

I finally got a picture and the recipe online which I use to make brownies. These dark, brown calorie-bombs are so tasty.. As I'm writing this, I'm baking some at my parents home. My sister helped me a bit making sure she didn't melt away with the smell. Well, she got to wait some more half an hour!

The recipe has been stolen from the BBC website. The brownies pictured are from late January 2007.

Funny story! I had a christmas party (which was not much about christmas at all) with my friends in Aschaffenburg (Germany). My duty was to come up with a dessert and I proposed brownies. Well, I never actually made them!
So what I did a …