Today new version of JSON UDF functions: 0.2.1 was released. This is maintenance release which added no new functionality and only contains bug fixes. However, it also includes improvements for build ans test procedures. As usual, you can download source and binary packages at MySQL Labs. Binary packages were build for MySQL server 5.6.14. If you want to use other version of the server, you need to recompile functions.

What was changed? Let me quote the ChangeLog.

Functionality added or changed:

Added cmake option WITH_PCRE which alolows to specify if existent or bundled version of PCRE  should be used. Bundled is default on Windows. To compile with bundled version, run: "cmake . -DMYSQL_DIR=/path/to/mysql/dir -DWITH_PCRE=bundled", to turn bundled version off on Windows, run: "cmake . …

Before there was PERFORMANCE_SCHEMA, there was SHOW ENGINE INNODB MUTEX. As I wrote yesterday, these commands are useful for exposing internal locking operations that happen inside of MySQL. They are mainly useful for MySQL developers, but have some appeal for DBAs as well.

As part of an ongoing effort to cleanup the MySQL code-base and increase usability, the MySQL development team is interested in hearing feedback from users who currently use the command SHOW ENGINE INNODB MUTEX.

Specifically:

• Is there a use case for the command that is not well satisfied by Performance Schema?
• Would you be adversely affected if SHOW ENGINE INNODB MUTEX were to be deprecated?
…

I took the MySQL 5.6-Exam today and it really is not easy. Lets get straight to the facts i remember:

• I had 130 questions and 180 minutes time
• I needed 155 minutes but i was a bit exhausted at the end so went a bit quicker through the questions as in the beginning. Normally i am a fast exam taker and only need a third of the time.
• The option to eliminate obviously wrong answers by CTRL-Rightclick is often really helpful

What you should learn in the following order:

• Performance Schema
• Replication Features, especially GTID, and mysqlbinlog-usage
• Partitioning
• Optimizing MySQL Queries
• MySQL Enterprise Backup-Features
• Anything else (command line options, Windows Cluster, mysqldump, mysqlshow, etc..)

I had 3 or 4 questions where i thought that the answers (or the question) were not correct or no …

So, after installing Workbench 6.0.7 on my pc, and playing around with the MySQL Utilities that are included, I thought I’d do similar to what others have done (Thanks Tony D.) and share my experience on how I’ve used them. If you haven’t installed Workbench before, you might want to check your platform first: http://www.mysql.com/support/supportedplatforms/workbench.html.

So, even if you’re not using any of the recent versions and editions of Workbench (Utilities comes with all of them, Tools menu -> “Start Shell for MySQL Utilities“) you can just download the standalone scripts on a Linux machine. Flexibility being the name of the game again. …

So, after installing Workbench 6.0.7 on my pc, and playing around with the MySQL Utilities that are included, I thought I’d do similar to what others have done (Thanks Tony D.) and share my experience on how I’ve used them. If you haven’t installed Workbench before, you might want to check your platform first: http://www.mysql.com/support/supportedplatforms/workbench.html.

So, even if you’re not using any of the recent versions and editions of Workbench (Utilities comes with all of them, Tools menu -> “Start Shell for MySQL Utilities“) you can just download the standalone scripts on a Linux machine. Flexibility being the name of the game again. …

I took a quick look at MariaDB 10.0 single-treaded performance (simple read-only sysbench). One thing immediately leaps to the eye, and I thought it worthy of mention. It contains an important lesson about the use of synchronisation primitives and in particular "atomic operations" in MariaDB (and MySQL).

I am using the Linux perf tool on this sysbench command:

  sysbench --num-threads=1 --test=oltp --oltp-test-mode=simple --oltp-read-only --oltp-skip-trx

Look at the top offender in the output from perf report:

  1,54%  mysqld  mysqld               [.] set_thread_state_v1

The only thing this does is set a string for SHOW PROCESSLIST (and the like) about what the thread is doing. And we are spending a whopping 1.5% of the total time doing this.

And why? That becomes clear when looking at the disassembly …

Thanks for the comment Rudy, and apologies for not replying sooner.
To be honest, mine was just a mini project to showcase MySQL Cluster on a small solution. As you quite correctly state, Cluster is aimed at storing as much as it can in memory, so, this needs to be taken into account when deploying Cluster on any platform, not just R.Pi ‘architectures’. For a proper solution, it’s always best to evaluate Cluster for our app that, maybe it’s currently using InnoDB, and we want to go 99.999% with it. The MySQL Cluster Evaluation Guide should help us understand whether Cluster is, or isn’t, an appropriate fit. In a R.Pi we’d have to think about exactly what we want to achieve first.

We have always received quite few questions here at Percona Support on how to avoid the dreaded “Too many connections” error, as well as what is the recommended value for max_connections. So, in this article I will try to cover best possible answers to these questions so others can mitigate similar kinds of issues.

My colleague Aurimas wrote a wonderful post some time back about changing max_connections value via GDB when MySQL server is running to get rid of the “Too many connections” error without restarting MySQL. You can check here for details.

By default 151 is the …

MySQL Enterprise Monitor (MEM) is the monitoring solution offered as part of MySQL Enterprise Edition and MySQL Cluster Carrier Grade Edition. In this blog, I will not go into details of the features of MEM, but rather focus on the case where you want to install MEM 3.0 to try it out on your personal desktop or laptop.

A trial version (the full product, but the can only be used for 30 days) is available from Oracle’s Software Delivery Cloud. If you are a MySQL customer, it is recommended that you download MEM from My Oracle Support (MOS).

Once you have downloaded and extracted the installation binaries, you can start the installation. You have the choice between using a GUI, text based, and unattended install. Here I will use …

With the holiday season fast approaching (or is it slow?), data bloggers have already adopted a festive mood, and this Log Buffer edition jubilantly captures and reflects that, and much more.

Oracle:

On December 4, 2013, Oracle will host a customer webcast to acquaint customers with the Oracle SuperCluster M6-32, Oracle’s most powerful engineered system for in-memory Oracle Database performance, Database-as-a-Service and application consolidation.

The ETL logic in BI Apps uses parameters in packages, interfaces, load plans, and knowledge modules (KM) to control the ETL behaviors.

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