Debunking GROUP BY Myths

April 30 2008

There is a popular myth about the SQL GROUP BY clause. The myth holds that 'standard SQL' requires columns referenced in the SELECT list of a query to also appear in the GROUP BY clause, unless these columns appear exclusively... read more

What MySQL can do to enter the off-line Web

April 30 2008

Disclaimer - views expressed in this blog (and this entry) are my own and do not necessarily reflect the views of MySQL AB Ever since I wrote my blog entry about Google Gears and the query tool for the browser... read more

Reporting MySQL Internals with Information Schema plug-ins

February 10 2008

Last week, I described how to use the MySQL plug-in API to write a minimal 'Hello world!' information schema plug-in. The main purpose of that plug-in is to illustrate the bare essentials of the MySQL information schema plug-in interface. In... read more

MySQL Information Schema Plugins: the best kept secret of MySQL 5.1

February 01 2008

MySQL 5.1 offers an extremely useful feature called information_schema plugins. This feature allows dynamic runtime loading of a shared library into the MySQL server to implement a table in the information_schema database. The SQL standard (ISO/IEC 9075-11:2003) allows database implementations... read more

Calculating the Financial Median in MySQL

December 17 2007

I believe I found a new method to calculate the median in MySQL. I would not be surprised if this method has been figured out by somebody else already. However, I can't seem to find any resources on the internet... read more

Random RDBMS and SQL Myths debunked

November 09 2007

A few times now, I've been wanting to write this down. I know: a lot of people will go *shrug*. Others may find me pedantic. Some of will say I'm being a smart-ass. Whatever...but I just got to write down... read more

Kettle Tip: Using java locales for a Date Dimension

September 03 2007

The Date dimension is a well known construct in general data warehousing. In many cases, the data for a date dimension is generated using a database stored procedure or shell-script. Another approach to obtain the data for a date dimension... read more

Google Gears: Webbrowser embedded Database

June 02 2007

Google Gears is an open source browser extension created by Google. It provides a framework that allows the creation of offline webbrowser applications. At the moment it provides three services: Local Server A data store for static resources. This allows... read more

So, are Database Stored Procedures Good or Bad?

March 13 2007

A little less than a week ago, I opened a zoomerang survey about database stored procedures. In this post, I’m presenting the results. In just a few days, the survey was visited 232 times, and no less than 155 people completed the survey! (There was a very small (2) number… read more

Stored procedures - Good or Bad?

March 07 2007

The topic of database stored procedures does not cease to divide the community of database application developers and DBAs. There are many articles around, expressing various opinions about this subject. But what do you think? Please let me know and take this survey. The survey contains 5 multiple choice questions,… read more

MySQL: Transactions and Autocommit

February 11 2007

Some people believe that the ability to commit or rollback multiple statements as a single unit is a defining characteristic of the concept of transactions. They draw the -false- conclusion that enabling autocommit is the same as disabling transactions. It is easy to demonstrate why this is not true. Autocommit With autocommit… read more

Finding Redundant Indexes using the MySQL Information Schema

September 26 2006

Peter Zaitsev’s blog entry on Duplicate indexes and redundant indexes certainly made a bit of a stir! It has already led to a new (mini) project by Baron Schwartz, the Duplicate index/foreign key finder which is publicly available on MySQLForge as a perl script. Daniel Schneller has entered the arena… read more

Refactoring MySQL Cursors

September 06 2006

Hi All, My name is Roland Bouman, and I’m a certification developer for MySQL AB. This is my first post on the O’Reilly database weblog, and I figured it would be nice to start with a technical article about MySQL cursors, a subject I have written about before on my blogger… read more