I’ve started an HTML manual for innotop, a “top” clone for MySQL. It includes screenshots. Right now I only have screenshots for the new U mode, which demonstrates how the User Statistics enhancements in Percona Server can show you which tables and indexes are most used.

MySQL 5.5 is set to ship GA soon so I thought I would create a series of blogs that highlight the key new features  I will start with a rundown of where we have made improvements and then expand into details as things progress.  MySQL 5.5 merges the technical architectures of the MySQL database with the InnoDB storage engine so that the two should now be considered one and will move in tandem for the most part from now on (We can do this now that Oracle owns both...)  That said, the key things to know about MySQL 5.5 and the re-architected InnoDB storage engine are:

• Oracle's InnoDB is the default database storage engine
• Performance and Scalability on Windows is on par or better than for other platforms
  
• MySQL now fully utilizes the computing power of modern multi-core architectures across all platforms
• Replication is better and easier to monitor, manage and use …

Quando o papo é Scale-Out, entram em cena as considerações relacionadas com o tipo de armazenamento do log binário, importante e, diria, fundamental recurso mantido pelo MySQL para que a replicação seja possível entre os servidor de bancos de dados MySQL. Os tipos de armazenamento começaram a variar de forma configurável desde a versão 5.1 [...]

The ASF threatens to withdraw from the JCP. The demise of the Symbian Foundation. And more.

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# The Apache Software Foundation said it will terminate its relationship with the JCP if its rights are not upheld.

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The max_allowed_packet variable is used to control the maximum size of a query sent to MySQL. It’s function is fairly well defined in the manual but there is a significant gotcha that exists when changing the size of max_allowed_packet while using replication.

When the replication threads are created the global max_allowed_packet value is copied in to the thread context like doing a set session command in the slave connection. This is done because replication enforces max_allowed_packet a bit differently than other threads. It accounts for both the size of the packet and the overhead of the replication header. This makes the max_allowed_packet enforcement accurate in replication but it means that the slave thread won’t account for set global max_allowed_packet=N until replication is restarted. It should be possible to do the same calculation while checking incoming packets but I haven’t looked into making a patch.

I think …

Python is a programming language that lets you work more quickly and integrate your systems more effectively. You can learn to use Python and see almost immediate gains in productivity and lower maintenance costs.

Go to devart.uservoice.com and share your ideas about new features you want to see in dbForge Studio for MySQL. Here you can do the following:

• Vote for features that are already in our roadmap, and they will get higher priority in our plans
• Suggest your own features, and if they get enough votes, we will include them to the roadmap.

Your opinion helps us to make our MySQL GUI Client better and more useful for you.

We have already started implementing the following features:

Export data of the several tables at once

Data Export …

Before I start a story about the data recovery case I worked on yesterday, here's a quick tip - having a database backup does not mean you can restore from it. Always verify your backup can be used to restore the database! If not automatically, do this manually, at least once a month. No, seriously - in most of the recovery cases I worked on, customers did have some sort of backup, but it just wasn't working, complete and what not. Someone set it up and never bothered to check if it still works after a while.

Anyway, this post is not really about the backups but rather about few interesting things I learned during last recovery case.

First, some facts about the system and how data was lost:

• MySQL had a dedicated partition on XFS file system
• Server was running innodb_file_per_table
• There was a …

The following is an edited transcription from the #mysql on the Freenode IRC Chat. It is here so that it can be referenced by the IRC bot on that channel.

G> So it's not necessarily a bad idea to use say an autoinc as the primary index of a table?

A> It's a very good idea to have an autoinc primary index. See the Manual.

T> A: I tend to prefer the natural primary key if one exists, unless ORM is an issue.

I> For Innodb autoinc is usually preferrable.



Continue reading "Natural keys vs. auto_increment"

innotop is a fine tool that every MySQL DBA should be familiar with. Although it takes a while to get used to, it's worth it. It's less than intuitive for most people, unless you grew up in Linux.
The other problematic part except the learning curve is the installation. It took me a while last time I had to install it, and this time re-installing it I've decided to write down the steps needed.

Most of the trouble I went through the first time around were with CPAN, and finding out that those Perl modules were available in RPM form saved me lots of time. Avoid CPAN if you can for this purpose.
Also, these steps should work on RedHat Linux as well, of course, but I didn't test it.

1. Download the compatibility version of the shared MySQL libraries. The …