Every MySQL DBA has at least peeked at a mysql.user table. But with the latest versions come some changes that many may have not noticed. The last three of the forty three columns — plugin, authentication_string, and password_expired — fields deserve a closer look.

First off, lets look at the entire table that is the output of DESC mysq.user run in MySQL Workbench and only the last few lines are shown for the sake of clarity.

The password_expired field is simply set to ‘N’ if the password is expired.
ALTER USER 'joeuser'@'localhost' PASSWORD EXPIRE;
The use will receive a message that their password has expired and they need to set a new one IF their client supports resetting password. The account is is “sandbox” mode where the use has …

[2017 update: MySQL 8.0.1 now features SQL-standard CTE syntax; more information is here ; the entry below, from 2013, shows how to work around the absence of CTEs in older MySQL versions.]

If you have been using certain DBMSs, or reading recent versions of the SQL standard, you are probably aware of the so-called "WITH clause" of SQL.
Some call it Subquery Factoring. Others call it Common Table Expression (CTE). In its simplest form, this feature is a kind of "boosted derived table".

Assume that a table T1 has three columns:

CREATE TABLE T1(
YEAR …

This is part two on a two-part series on the performance implications of in-flight data encryption with MySQL. In the first part, I focused specifically on the impact of using MySQL’s built-in SSL support with some rather surprising results. Certainly it was expected that query throughput would be lower with SSL than without, but I was rather surprised by the magnitude of the performance hit incurred at connection setup time. These results naturally lended themselves to some further investigation; in particular, I wanted to compare performance differences between MySQL’s built-in SSL encryption facilities and external encryption technologies, such as SSH tunneling. I’ll also be using this post to address a couple of questions posed in the comments on my original article. So, without further ado….

Test Environment

The …

We are announcing the new MySQL for Developers course. This training:

• Takes advantage of both SQL and NoSQL
• Shows you how to plan, design and implement applications
• Brings you realistic examples, interactive instruction and hands-on exercises using Java and PHP
• Covers MySQL 5.6 features including optimizer improvements
• Helps you prepare for the MySQL 5.6 Developer certification.

You can take this course as a:

• Live-virtual event: Take this course from your own office; no travel required. You can choose from a selection of events on the …

Great… Finding the right repo sometimes was a very big problem

Ahoi,Attending DOAG 2013 next week, Im going to give two talks (Applikationsvirtualisierung mit LXC and MySQL Replikation).Also Im invited to attend a MySQL Expert Panel, where you can let a bunch of MySQL Experts discuss your questions ;)DOAG is afaik the biggest Oracle Event (and even not driven by Oracle) in Europe.A good place to have nice discussions and learn a lot of new stuff :)
Hope to see youErkan Yanar

One of the best DBA questions I was ever asked in an interview, was to try and estimate required disk space for an application using a back-of-the-envelope calculation.

The idea behind a question like this, is that it is a thought exercise. Its aim is to better test competency than some of the simple questions that can be Googled for an answer (i.e. whether or not you know the answer is not important. You will in 2 minutes :)) Unfortunately I have also seen it negatively affect candidates that are not native English speakers, so be aware that your mileage may vary.

Today I wanted to try and recreate the back-of-the-envelope exercise that I was asked to complete. For simplicity the question will be restricted to database size and not include RAM or IOPS estimations.

Scope of Problem

“We are designing a new system to store application users for a very demanding system. There is only one table, but it is …

Economist says that Physics suggest that storms will get worse as the planet warms. Typhoon Haiyan in Philippines, bush-fires in Australia, floods in China, and extreme unpredictable weather across the planet is a sober reminder. Good news is that technology and awareness is rising, and so is the data. Database technologies are playing their part to intelligently store that data and enabling the stakeholders to analyze and get meaningful results to predict and counter the extreme conditions. This Log Buffer Edition appreciates these efforts.

Big Data:

Big Data Tools that You Need to Know About – Hadoop & NoSQL.

Dave Stokes is …

One of the most common errors in development is where a loop or a retrieval by index falls short or long by one unit, usually because of an oversight or a logic in coding.

Of the following snippets, which one will run 10 times?

/* #1 */    for (N = 0 ; N < 10; N++) printf("%d\n", N);

/* #2 */    for (N = 0 ; N <= 10; N++) printf("%d\n", N); 

/* #3 */    for (N = 1 ; N <= 10; N++) printf("%d\n", N);

/* #4 */    for (N = 1 ; N < 10; N++) printf("%d\n", N);

The question is deceptive, as there are two snippets that will run 10 times (1 and 3). But they will print different numbers. If you ware aiming for numbers from 1 to 10, only #3 is good.

After many years of programming, off-by-one errors are rare in my code, and I have been able to spot them or prevent them at first sight. That’s why I feel uneasy when I look at the way parallel replication is enabled in …

The problem

About two weeks ago I noticed my iPhone 5 had a faint, but ugly pink hue in the center of the screen. At first I suspected some software issue, because it looked as if the hue was exactly in the area an iOS7 table view uses for its cells to be displayed (i. e. full screen, but with a few points of inset on the left and right edges). Apparently someone must have left some kind of view with a red-ish color behind the table view that was now shining through, because of all the translucency effects iOS7 comes with.

Turns out though, that this was going on in all kinds of apps, including Instapaper, Pocket, Chrome, Safari Calendar etc. All those certainly would not put any views behind the actual content. Getting more suspicious I showed the problem to several colleagues who all did not see it at first, but once I had pointed it out to them (most visible on a white background) none of them could "unsee" it, …