MySQL’s version-specific conditional comment syntax confused me for the longest time. Then I learned about printf formatting rules, and it all became clear. Read on if you don’t already know what I mean. First I’ll explain what I’m talking about. MySQL allows specially formatted comments with a server version number embedded in them. Servers newer than the version number will execute the commented-out code, and older servers won’t. This is really useful sometimes.

http://tinyurl.com/2qmusm

Need I say more? Go download the slides, video and audio from the 2007 MySQL Users Conference & Expo. I have no plans to take anything down, so please download wisely, and take only what you need. If there’s demand, I can make higher-quality versions available. I can also burn DVD’s of the content if that’s desired.

Enjoy!

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 in an aggregated expression. MySQL is often accused of violating this standard.

In this article I will attempt to debunk this myth, and to provide a more balanced view regarding MySQL's treatment of GROUP BY at the same time.

To do that, I will first demonstrate that MySQL can be instructed to only accept GROUP BY clauses that include all non-aggregated expressions referred to in the SELECT list, thus making MySQL's behaviour conform more to that of other well-known rdbms-products.

Second, I will show that it is very important to clearly define which …

273 people have cast their vote on the most wanted replication feature…

Cast your vote before the poll disappears:

http://dev.mysql.com/

Thinking further about Microsoft's FUD campaign to threaten patent lawsuits against customers for using Linux, I was wondering if this isn't really a result of a bigger issue facing the company: Google Envy.  As I mentioned previously, Microsoft is competing on several fronts.  And while they hate like hell to give up market share to open source that would threaten their cash cow Windows or Office business, the bigger issue for the company is that their core businesses are being disrupted.  And Microsoft is in last place when it comes to new online businesses like hosted applications, online search, email, blogging, videos, and music.  (Ok, to be fair, Microsoft has come from behind in the past in other markets like gaming and accounting software.)  As is the case in many mature markets, their core …

I get the opportunity see a lot of different MySQL Cluster configurations and most of them does not configure the disk subsystem in a good way. E.g, the redo log is way to often not correctly dimensioned. Wrongly dimensioned buffers affects system stability!!

There are also some buffers related to communication and disk, that is important to setup. At the end here you will find a good configuration template that you can use, but first we will have a brief discussion about the disk


Configuring the disk

In MySQL Cluster, it is very important to dimension the redo log properly in order for System restart and Node restarts to work. In MySQL Cluster, the redo log must be large enough to accomodate changes that happens over three Local Checkpoints (LCP). When the third LCP has been written, then the redo log can be recycled. The LCP is the image of the DataMemory which is written to disk, so if you …

Well this is going to be a short blog post that will not really manage to summarize all the experience on my San Francisco, Santa Clara, San Francisco, Austin, Tampa, Boston, Chicago, Zürich, Berlin, Güstrow, Berlin, Zürich round trip I was on for the last 4 weeks. But anyways, I wanted to mention that the slides from php|tek are now linked in the slides section.

I did a talk on various strategies of how to bridge relational databases and object-oriented programming. In retrospect I should have submitted this as a "double feature" talk, so that I could cover more ground on the actual using of the existing packages in the PHP space.

The other talk was on database locking. I think the biggest eye opener for people in that talk was about how MVCC, found …

I generally find MySQL Sever sufficiently tested, meaning at least minor version upgrades rarely cause the problems. Of course it is not perfect and I remember number of big issues when some releases could not be used due to behavior changes in them and when something had to be rolled back in the next release.

But generally I think MySQL is doing much better than a lot of other projects in this respect.

Major version upgrades become more painful recently. In MySQL 3.22->3.23 upgrades or 3.23->4.0 upgrades you really could just swap binary and try out new version and if you need to get back you just swap binaries to the old version. I think it was great.
In MySQL 4.1 and later more caution is required because you could screw your data, for example by specifying utf8 as default character set together not to mention infamous timestamp format change which forced to change a lot of applications.
MySQL 5.0 added more …

I know Alexa is very controversial and we don't like to compare with Flickr, but...

Blue: Fotolog
Red: Flickr
Green: Bebo

We reached 8 million members recently (7 weeks from 7 million) and are currently ranked 18th on Alexa (yeah, I know it jumps around :)).

I added bebo because rumor is that Yahoo! wants to grab it for a cool billion.

The value of timely information regarding maintenance releases, including specific information of what bugs have been fixed and when and where to get the upgrade, proves very compelling for those DBAs and developers with little to no bandwidth. The good news is MySQL Enterprise takes the guesswork out of deciding which version of the MySQL server you should be running by providing regularly scheduled Monthly Updates and quarterly Service Packs for the Enterprise Server.