I think every person responsible for Development or Operations of growing application sooner or later have to decide on couple few questions on how to tackle application performance. These questions are:

• Should we Optimize Application or get more Hardware ?
• Should we do things ourselves or hire an experts to help us ?

The answer on these questions actually depend on a lot of things, some of which we'll try to cover here.

The things which usually define best solution are economics , resources and risks .

First lets talk about optimizing application vs getting better hardware.

With application optimization typically you have rather interesting relationship between "effort" and "result" typical application would have number of low hanging fruits …

Thank you all for taking the time to respond to the little challenge I posted yesterday! I am pleasantly surprised to note that so many people took the time to post a solution. And most people provided the correct answer too: you are all entitled to a well deserved discount to register for the MySQL User's conference!!!

For those of you interested in the solution: there are two different forms of the CASE statement syntax: the so-called simple case and the searched case.

The simple case selects one WHEN...THEN branch by comparing the value of the expression that appears after the CASE …

I’ve been making preparations this week for the panel I’m moderating at this year’s OSBC conference in San Francisco. The title is The State of the Open Source Database Market, and we’re lucky enough to have a great panel, featuring: Andy Astor, CEO, EnterpriseDB; Roger Burkhardt, President & CEO, Ingres; Ken Jacobs, VP Product Strategy, Server Technologies Division, Oracle; and Zack Urlocker, EVP of Products, MySQL.

Everyone’s open to answering whatever questions the audience throws at them (within reason) so with the combined knowledge and expertise on offer it should be an interesting and entertaining session. I’ll try not to get in the way!

I’m also looking forward to putting some names to faces as this will be my first OSBC event. I’m here all …

"So hard hard is that MySQL DBA Certification?" I was asked by two different individuals just a few hours apart. The first was a prospective candidate asking for study guidance. The second was project manager who has the general view that certifications are not worth the paper they are printed on and only represent someones ability to regurgitate answers previously fed to the test taker.

So how tough is the test? Forty percent of those taking the DBA-I fail. DBA-II only fails twenty four percent.

I would hope that simple regurgitation would provide more than a sixty percent pass rate.

The Developer exams have a 72 and 75 percent pass rate. The Associate exam has a 77 percent pass rate and the cluster is just over 80 percent.

The MySQL DBA exams are tough. I had been using MySQL since the days when you downloaded it from tcx.se when I took the exams last year. The study guide and …

Jason Hunter writes in email:

Perl is the duct tape of the internet. Created by Larry Wall in 1987 and made famous with his Programming Perl "camel book" published by O'Reilly, it's the tool sysadmins use to keep things running.

We're proud to announce we've finished loading the Perl.org mailing list history into MarkMail. A total of 530,000 emails across 75 lists. The lists don't go back to 1987 (boy that'd be cool if they did). But that's all right; who really needs tech support against Perl 1.000?

What we have here is traffic starting with the migration to the Perl.org setup in 1999:

Enjoy! And if anyone has earlier archives, let us know.

This is awesome. Markmail also has mailing list …

In MySQL 5.1 Cluster Certification Study Guide at page 151 there’s the following sentence: “InnoDB operates with the REPEATABLE READ isolation level, which still allows phantom reads but suppresses non-repeatable reads”.

The sentence is wrong: the REPEATABLE READ isolation level for InnoDB engine doesn’t allow phantom reads.

In some database systems, REPEATABLE READ isolation level allows phantoms, such that if another transaction inserts new rows in the interval between the SELECT statements, the second SELECT will see them. This is not true for InnoDB; phantoms do not occur for the REPEATABLE READ level. SERIALIZABLE isolation level is similar to REPEATABLE READ with the additional restriction that rows selected by one transaction cannot be changed by another until the first transaction finishes. (as stated by MySQL 5 Certification Guide)

Here is an example to demonstrate such a behaviour.

To …

Someone pointed out to me that the publisher has made an electronic copy of my EnterpriseDB: The Definitive Reference book available as a PDF on their web site.

It's been removed.

When you work in the same field for several years, you risk to become effective but unimaginative. You may be good at coding queries or designing tables, but sometimes you lose track with your origins, when you were a creative programmer, who used to tweak the intricacies of C++ or Perl to create marvelous useless brilliancies.
If you recognize yourself in this picture, and wish you could have a spark of that enthusiastic force that made you learn new languages and idioms, despair not. Beat Vontobel session …

So, I just fixed a behavior in PEAR::DB. In isManip, a regular expression is called on every query that goes through the PEAR::DB layer. That sucks btw, but the purpose of function is to tell the classes that inherit from DB that the query passed is a query that affects data.

The code is as follows

 function isManip($query)
    {
        $manips = 'INSERT|UPDATE|DELETE|REPLACE|'
                . 'CREATE|DROP|'
                . 'LOAD DATA|SELECT .* INTO .* FROM|COPY|'
                . 'ALTER|GRANT|REVOKE|'
                . 'LOCK|UNLOCK';
        if (preg_match('/^\s*"?(' . $manips . ')\s+/i', $query)) {
            return true;
        }
        return false;
    }

Then in mysql.php there is this

function affectedRows() …