MySQL 5.6 seems to be ready for GA. I have no inside information about it, but from some clues collected in various places I feel that the release should not be far away. Thus, it's time for some serious testing, and for that purpose I have worked at updating MySQL Sandbox with some urgent features.

I have just released MySQL Sandbox 3.0.28, with more support for MySQL 5.6. Notably in this release, there is suppression of MySQL 5.6 annoying verbosity, additional suppression of more annoying warnings ( actually a bug) when using empty passwords

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While testing MySQL 5.6, I came across some curious values for the new values used to set the crash-safe slave tables. To get safety, we need to set relay_log_info_repository and master_info_repository to 'TABLE'. That way, the replication information, instead of going to a file, will be saved to two tables in the mysql schema (mysql.slave_relay_log_info and mysql.slave_master_info).

So I was setting these values back and forth between 'FILE' and 'TABLE', until I made a "mistake." Instead of typing

set global relay_log_info_repository='table';

I wrote

set global relay_log_info_repository=1;

To



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Users are safer

MySQL 5.6.8 was announced a few days ago. You can download it from the MySQL downloads page

This is the second release candidate of MySQL 5.6, and it is strange. My understanding of a release candidate is something that is stable, its features committed long time ago, and the release will just attempt to fix bugs. Instead, there are features that were not in the first release candidate. This one strikes me as really odd (quoting from the announcement) :

On Unix platforms, mysql_install_db supports a new option, --random-passwords, that provides for more secure MySQL installation. Invoking mysql_install_db with this option causes it to perform the following actions in

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One of the surprises of MySQL 5.6 was that the mysql.host table was missing. How did I realize it? Because make_sandbox, the basic installation brick of MySQL Sandbox failed to complete. What happened is that MySQL Sandbox, before claiming success, checks if some key elements are available. One of such elements is the 'host' table, which, unbeknown to me, had been deprecated, and was eventually removed in yesterday's release. As a result, installation of MySQL 5.6.7 fails.

The fix is quite easy, and I released it today. It is available in MySQL Sandbox 3.0.26, which you can get from Launchpad and CPAN.

This fix is minimal because it barely allows you to install MySQL 5.6. However,

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There has been a lot of talk about MySQL 5.6 replication improvements. With few exceptions, what I have seen was either marketing messages or hearsay. This means that few people have really tried out the new features to see whether they meet the users needs.

As usual, I did try the new version in my environment. I like to form my own opinion based on experiments, and so I have been trying out these features since they have appeared in early milestones.

What follows is a list of (potentially) surprising results that you may get when using MySQL 5.6.
All the examples are made using MySQL 5.6.6.

Gotcha #1 : too much noise

I have already mentioned that MySQL 5.6 is too verbose when creating data directory. This also means that your error

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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

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When I install a MySQL package using MySQL Sandbox, if everything goes smoothly, I get an informative message on standard output, and I keep working.

This is OK

$HOME/opt/mysql/5.5.15/scripts/mysql_install_db --no-defaults \
  --user=$USER --basedir=$HOME/opt/mysql/5.5.15 \
  --datadir=$HOME/sandboxes/msb_5_5_15/data \
  --lower_case_table_names=2
Installing MySQL system tables...
OK
Filling help tables...
OK

To start mysqld at boot time you have to copy
support-files/mysql.server to the right place for your system

PLEASE REMEMBER TO SET A PASSWORD FOR THE MySQL root USER !
To do so, start the server, then issue the following commands:

/Users/gmax/opt/mysql/5.5.15/bin/mysqladmin -u root password 'new-password'

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In the yet to be released MySQL 5.6.6 DMR, there has been a change to the restriction of just one TIMESTAMP column with the DEFAULT CURRENT_TIMESTAMP and ON UPDATE CURRENT_TIMESTAMP syntax. It is now possible for any TIMESTAMP to have either column defintion.

More information at http://dev.mysql.com/doc/refman/5.6/en/news-5-6-5.html

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  [Read more...]

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

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The default storage engine is InnoDB, or is it not?

When MySQL 5.5 went GA, the biggest piece of news was that the default storage engine is now InnoDB. Good news, and hope for a better future, as InnoDB is the most reliable storage engine available for MySQL.

Therefore the expectation is that MySQL 5.6 follows in its steps, and we should see less and less of MyISAM in the database.
The privileges tables, however, are still MyISAM. I was not really expecting to see them disappear so quickly, as I have seen how much work it has been for Drizzle to get rid of them, and even them had to keep MyISAM alive for temporary tables.
However, I was surprised to see that the new tables for replication metadata, the ones that replace the files master.info and relay_log.info are MyISAM by default.
The




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If you like fresh features, you should not miss this one. MySQL 5.6.2 includes, among other improvements, the implementation of Time delayed replication, a feature that lets you tell the slave not to apply changes from the master immediately, but to wait N seconds.The feature is documented in WL#344. (There was a manual online as well together with the binaries for MySQL 5.6.0, but they were removed after a few days for a good reason. I am confident that both the manual and some binaries will eventually show up soon).
Since as of today there are no binaries
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While I was presenting my partitioning tutorial at the latest MySQL Conference, I announced a new feature that was, as far as I knew, still in the planning stage. Mattias Jonsson, one of the partitions developers, was in attendance, and corrected me, explaining that the feature was actually available in a prototype.
So, we can have a look at this improvement, which I am sure will make DBAs quite happy. The new feature is an instantaneous exchange between a partition and a table with the same structure. Using this feature, you can transfer the contents of one partition to one table, and vice versa. Since the transition is done only in the
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