Mysql is usually pretty fast by default, but to keep performance to the max sometimes requires knowledge on how mysql works and how to write queries that does their job most efficiently. Today we ran across a simple example which illustrates that mysql’s ability to use an index depends on the way you write the query. Let’s make a simple table and add an index on the date column:

create table members (
	m_id integer auto_increment primary key,
	m_name char(20),
	m_since date not null
);

create index ix_m_since on members (m_since);

Most databases seems to be well designed when the systems needing them are launched in the first version – but the slowly as the systems evolve (often grow beyond their initial requirements) – the database design seems to go down the drain. Here are a few tips on what to think about when you design a database or alter it.

First rule: Remember the goal of the system.

Different systems have different requirements and thus require different database designs. Some system are build for the web, some are build for medical journals and others just to solve a practical problem. If you’re building websystems, your main concern is probably speed. If you’re building financial system, data integrity and consistency is probably your main concern. Make sure your database design is made for the goal.

Today’s evil headache was caused by something as simple - yet annoying - as a two HTML form elements having the same name (but different types and uses in the form). The lesson learned is that if a field in a form is submitted but contains nothing - check if another object in the form has the same name and make changes if you need to.

A man and his sister, who sent unsolicited junk email to millions of America Online customers, have been convicted in the first felony prosecution of distributors of spam in the US.

Finally, the US is beginning to put spammers behind bars, thank you.

So, I’ve been wondering if I should by a Mac. Windows works for me, but causes a fairly large number of headaches. Linux is nice for server use, but I’m not nerdish enough to get a desktop running. With the many positive reviews, switching stories and others I was thinking of going Mac. Since OS X was introduced Mac machines runs on a BSD core which makes it almost familiar grounds for people who knows the Unix world. Since the introduction they kept an amazing pace and regularly introduced new innovative features at regular intervals.