For folks who are looking at upgrading MySQL to a newer version there is good documentation in the MySQL docs (for example, upgrading from 4.0. to 4.1). My (limited) experience is that folks tend to focus on moving the data between versions, and don't always think about the other ramifications involved in upgrading to a new major version of MySQL.

You'll note that in the upgrade instructions the first step is focused on the behavior of MySQL:

Check the items in the change lists found later in this section to see whether any of them might affect your applications. Note particularly any that are marked Incompatible change. These result in incompatibilities with earlier versions of MySQL and you should consider the implications of these incompatibilities before you upgrade. Note particularly the items under "Server Changes" that …

Hi,

It has been a while since I last posted. We have been busy testing MySQL Cluster, MySQL Replication and MySQL Cluster Replication. Good news is the serious bugs are getting harder to find. This is allowing us to spend some time automating more testing like configuration and up/down grade testing for example.

The documentation guy for cluster, Jonathan "Jon" Stephens, has been doing great work to expand the Cluster on-line manual. If you have not been out there in a while to review you should have a look.

http://dev.mysql.com/doc/refman/5.1/en/mysql-cluster.html

I feel very positive about this version of the cluster as it has had more hands on testing then ever before. The testing includes: Functional, Negative, Load/Stress, Performance, Recovery, Network Failure, etc...

The new Disk Data will allow customer with huge database to start taking advantage of the …

I fell for it. I commented on the Log Buffer and shortly after that I was offered to host an issue. Here we go, then. Welcome to Log Buffer #12!

Confessions of an IT Hitman by Dratz features a strong message: Don't build a data warehouse, arguing that most of the times a DW is built, it's just because a clueless customers was either listening to buzzwords from a salesman or following the latest trend. The key message, for the ones who missed the build-up of the data warehousing movement during the past decade, is DW is a business solution, not a technology solution. OTOH, there are …

Tomorrow, I have been living a month in Munich. Relocating to Germany brings me closer to MySQL customers, users, and developers. Already, I’ve attended several meetings (OK, still just internal ones) that I wouldn’t have, from Finland.

Looking forward to plenty of interactions with locals, starting from the MySQL Kundenkonferenz Thursday 19.10.2006 here at the Park Hilton, right here in Munich.

Log Buffer #12, a review of the week’s database blogosphere, has been published by Giuseppe Maxia, The Data Charmer. Take it away, Giuseppe!

I have just released the first Beta version of PrimeBase XT. Besides MySQL 4.1.21 support it is also available as a pluggable storage engine for MySQL 5.1. As far as I know, PBXT is the first full featured engine to be released in this form.

The engine can be downloaded (at http://www.primebase.com/xt) and built separately from MySQL. Currently, a reference to a MySQL 5.1 source tree is required to build the plug-in. However, in the future things will be even easier. Lenz Grimmer has told me that the plan is to include the required headers in the mysql-devel package. Then it will only be necessary to install the mysql-devel package in order to build the engine.

Still further in the future, once 5.1 is released, I will be able to make the PBXT engine available as a binary download for a number of platforms.

Once you have built the PBXT engine, you …

In case you missed its mention on Slashdot, the Financial Times has a funny (and telling) column today by James Boyle (Professor, Duke Law School) on the dark underbelly of the "long tail. You remember the long tail, right? It's manna from heaven - a chance for the Internet to enable a wider variety of sellers to find the wider variety of buyers than our previous markets have allowed.

Well, maybe life under the long tail isn't as rosy as life pontificating about the long tail, as Boyle discovers:

The academic in me has been very interested by the much hyped arrival of the “long tail” economy – the idea that the future lies in using the efficiency of the internet to sell smaller quantities of more goods (think of the astounding …

Almost six months ago, I firstly wrote about the effect the EPLA could have on software patents in Europe in this blog entry. I reiterated this concern on various occasions, including the Commission’s July 12 hearing. Earlier this month I published a two-page diagram and a three-page briefing document to explain the nature of the problem.

My related concerns are shared by a growing number of people and organizations. Yesterday, the Greens/EFA group in the European Parliament issued …

I've been very lucky, I got a paper accepted for the Australian Computers in Education Conference which is being held 2-4 October in Cairns, Far North Queensland. So I'm heading North, about 1850 km, as I live in Brisbane in South-East Queensland. Cairns is a great place, I actually lived there for a while. It's where the tropical rainforest meets the great barrier reef.

So, about my talk. It's actually about a pet project of mine, and I prepared the paper together with Shaun Nykvist from the Queensland University of Technology. The paper is called Introduction to the pragmatic teaching of database concepts and in it we look at the possibilities for teaching relational database fundamentals without getting bogged down in theory. And we're not thinking "monkey-see monkey-do" …

My favorite question during Interview for people to work as MySQL DBAs or be involved with MySQL Performance in some way is to ask them what should be tuned in MySQL Server straight after installation, assuming it was installed with default settings.

I'm surprised how many people fail to provide any reasonable answer to this question, and how many servers are where in wild which are running with default settings.

Even though you can tune quite a lot of variables in MySQL Servers only few of them are really important for most common workload. After you get these settings right other changes will most commonly offer only incremental performance improvements.

key_buffer_size - Very important if you use MyISAM tables. Set up to 30-40% of available memory if you use MyISAM tables exclusively. Right size depends on amount of indexes, data size and workload - remember MyISAM uses OS cache to cache the data so you …