The latest releases of MySQL Sandbox, in addition to deal with minor bugs, have mostly been necessary because of compatibility issues in MySQL, both 5.5 and 5.6.

When I found that MySQL 5.6 has some InnoDB tables inside the 'mysql' schema, I had to change the way that the sandbox used to remove all contents (the ./clear command.)

To achieve a smooth clean up, MySQL Sandbox now performs a dump of the mysql schema, and uses that saved data to restore the schema after a complete wipeout.

Unfortunately, when 5.5.30 was released, this operation resulted in a warning, due to a behavioral change.

After a careful change, and about 1200 unit tests, the latest version of …

The blog title says it all: Do we need a MySQL Cookbook? I tend to think so.

This seems to be something that is missing with current MySQL documentation. There is lots of information available but finding the appropriate bit can be quite tedious and it often requires looking in multiple places.

A lot of other software has such books, but for some reason MySQL seems to be missing one.

A recent example comes from a “documentation feature request” I posted today: http://bugs.mysql.com/bug.php?id=68171. MySQL 5.6 provides a way to “move InnoDB tables” from one server to another. There are many reasons why you may want to do it, but the documentation is currently rather sparse. A simple “example recipe” for this would be good, as would an equivalent recipe for other engines where you can do this such as MyISAM. This is just an isolated …

On Friday last week, after the intensive days of the conference, Ars Technica wrote and published a nice article about MariaDB including many of the messages we had been delivering during the conference, http://arstechnica.com/business/news/2012/04/mysql-founders-latest-mariadb-release-takes-enterprise-features-open-source.ars.

MariaDB seals

Last year, when it became clear that O’Reilly wasn’t going to arrange the MySQL user conference in the future, there was a lot of discussion on who should arrange it. In the end Percona was pretty fast informing everyone that they had booked the convention center in Santa Clara to arrange the conference this year. Now with the …

The Percona Live MySQL Conference and Expo 2012 is over. Together with the SkySQL solutions day, it has kept me occupied for 4 full days, from early morning to late at night.

I have to say that I am pleased. The quality of the organization was very high, with a very good lineup of speakers and an excellent technical support.

As usual, I have learned a lot during this week, either directly, by attending talks, or indirectly, by meeting people who told me what was juicy at the talks that I had missed. And I have met new interesting people, and caught up with the people that I know already.

This conference was particularly intense also because I got myself involved in 5 talks, which was probably more than I should have. How did I end up with such a task? It's a long story. …

We are pleased to announce the immediate availability of MariaDB 5.5.23. This stable (GA) release incorporates MariaDB 5.3.6 and MySQL 5.5.23, some performance improvements, and bug fixes.

• MariaDB 5.5.23 Release Notes
• MariaDB 5.5.23 Changelog
• MariaDB 5.5.23 Downloads

Please see the What is MariaDB 5.5 page for an overview of MariaDB 5.5.

Sources, binaries, and package downloads are available from our …

On March 21st I will be in Paris, to attend the OTN MySQL Developers Day. Oracle is organizing these events all over the world, and although the majority are in the US, some of them are touching the good old European continent. Previous events were an all-Oracle show. Recently, the MySQL Community team has been asking for cooperation from the community, and in such capacity I am also presenting at the event, on the topic of testing early releases of MySQL in a sandbox. Of course, this is one of my favorite topics, but it is quite appropriate in this period, when Oracle has released a whole lot of preview features in its MySQL Labs. Which is another favorite topic of mine, since I was the one who insisted for having the Labs when I was working in the …

We are pleased to announce the immediate availability of MariaDB 5.5.20-alpha. MariaDB 5.5.20 is the first Alpha release in the 5.5 series. We hope to follow it up soon with a beta 5.5 release.

MariaDB 5.5.20-alpha is a merge of MariaDB 5.3 and MySQL 5.5 with some limited additional bug fixes. This is the first 5.5-based release, and we are releasing it now, intentionally without any extra features (and with it missing some planned features) to get it into the hands of any who might want to test it. Extra features planned for MariaDB 5.5 will be pushed into future releases.

As with any alpha release, MariaDB 5.5.20-alpha should not be used on production systems.

The Release Notes page has some notes on the release. There is also a  …

I see that MySQL 5.5.21 has just been released. This sounds interesting. I’m mainly running 5.5.16 which has been broadly stable, but I have been caught by a few important issues which 5.5.21 fixes according to the change list:

• Bug #57480
• Bug #61104
• Bug #54035

These together with a few earlier fixes after 5.5.16 are certainly interesting to me, so I’m eager to try out 5.5.21 and see how it fairs.

MySQL, like a lot of other software, has many knobs you can tweak. Most of these knobs may affect behaviour, but more importantly most affect the memory usage of the server, so getting these settings right is very important.

Most of MySQL’s memory is really used just as a cache, in one form or another, information that otherwise is on disk. So ensuring you have as large a cache as possible is important. However, making these memory sizes too large will trigger the server to start swapping and possibly can cause it to crash or cause the kernel to kill the process when it runs out of memory.  So that’s something we want to avoid.

Certain settings affect memory allocation on a per connection/thread basis, being bounded by thread_cache_size and max_connections.  If you configure for the worst behaviour (max_connections) you may end up not actually using all the memory you have available, memory which normally could be …

For those who saw my previous post about the crashing (regression) bug with SELECT COUNT(DISTINCT) on InnoDB with Primary Key (PK), you’ll be interested to know my test case does not crash in 5.5.18 (which was just released).

I’ve only tested my test case thus far, but it seems fine.

Unfortunately, the fix is not mentioned in the 5.5.18 changelogs though.

And there is no mention (yet, anyway) of a fix in the bug report I filed (though it was designated a ‘duplicate’, so it wouldn’t necessarily be updated).

I’m trying to get confirmation from the MySQL Dev Team on this (via the bug report), and will update this post if/when I hear anything.

I’ll also perform some of the …