Performance Schema (PFS) in MySQL 5.6 is coming yet more with many awesome new features. But, as it was already discussed in the past, enabling PFS instrumentation may create an additional overhead within your MySQL server, and as a result, decrease an overall performance.. The good news is that in MySQL 5.6 things become better and better ;-))

Well, you should understand as well, there is no miracle.. - some of most "hot" events within MySQL are happening over several millions(!) or tens/hundreds millions per second(!) -- so, it's sure, once such kind of event is traced, the overall overhead of the MySQL code may only be increased.. What is important that every instrumentation can be enabled or disabled dynamically, so you can go in depth progressively when tracing your events or bottlenecks, and stop …

MySQL and Continuent Tungsten at Constant Contact - How We Architected Our Replication StrategyThursday, June 14th10:00 am PDT/1:00 pm EDT19:00 CEST/18:00 BSTReserve your seat!Constant Contact is a provider of marketing services for over 500,000 small businesses and organizations worldwide, helping them to drive engagement and build relationships with current and prospective customers.As the

Stalls During DDL, Faster DROP TABLE Courtesy of the InnoDB Team

Mark Callaghan mentioned a simple issue on DDL operation. I found the back porting interesting, but not always a possible option. I have nothing to comment on top of what was already stated there, but I’ll mention it because it is interesting to read.

Why do threads sometimes stay in ‘killed’ state in MySQL?

Customers often ask me (and I believe all MySQL DBAs can relate): “Why did that query remain in a KILL state and does not go away?”

As we know, KILLed queries remain in MySQL until a clean up takes place, given that the action is not done synchronously. I found this article to be a good description of such events …

From the very first day at MySQL, the LOCK_open mutex have been an infamous bottleneck. The road to removing it as a bottleneck has been a long one. Already in the MySQL 5.4 beta release we had some first improvements of the LOCK_open. Other preparations were done in the solution of the bug #901 with the introduction of the MDL locking (metadata locking). Finally some preparations was done in early MySQL 5.6 DMR's where LOCK_open was removed as a mutex for a lot of activities where it wasn't really needed in opening and closing of files.

During an internal meeting in Trondheim at the end of 2010 I sat down with Dmitry Lenev and we came up with a solution where the LOCK_open is removed as a bottleneck. So finally this year we finalised this development and made it available as part of the MySQL 5.6 june 2012 labs release.

LOCK_open was used to protect a number of data structures related to the TABLE_SHARE object that …

Summary (aka TL/DR):

Support for Foreign Key constraints has been one of the most requested feature enhancements for MySQL Cluster. We are therefore extremely excited to announce that Foreign Keys are part of the first Labs Release of MySQL Cluster 7.3 – available for download, evaluation and feedback now! (Select the mysql-cluster-7.3-labs-June-2012 build)

In this blog, I will attempt to discuss the design rationale, implementation, configuration and steps to get started in evaluating the first MySQL Cluster 7.3 Labs Release.

Pace of Innovation

It was only a couple of months ago that we announced the General …

I blogged about how the April labs release 2012 made 5.6 improve performance of the Sysbench OLTP RO benchmark by more than 50%. Now we made an even more significant improvement of the MySQL 5.6 performance in the june 2012 labs release available at labs.mysql.com.

We've been able to improve Sysbench OLTP RO performance by a massive 270% going from MySQL 5.6.5 to the MySQL 5.6 june 2012 labs release. The benchmarks were made on an internal pre-release of the june labs release.

Also for Sysbench OLTP RW we made a very significant breakthrough in performance, the performance increase is 182% here.

The tests were made on a "monster"-box we have available at Oracle with 8 CPU sockets, each socket has an Intel Xeon 7540 processor that have 6 cores per socket and 2 threads per core. Thus a total of 96 CPU threads are available in the machine. The CPU frequency was 2.00 GHz and the available memory was 512 GB. …

With the release of MySQL 5.6 binary log group commit is included, which is a feature focused on improving performance of a server when the binary log is enabled. In short, binary log group commit improve performance by grouping several writes to the binary log instead of writing them one by one, but let me digress a little on how transactions are logged to the binary log before going into the details. Before going into details about the problem and the implementation, let look at what you do to turn it on.

Nothing.

Well... we actually have a few options to tweak it, but nothing required to turn it on. It even works for existing engines since we did not have to extend the handlerton interface to implement the binary log group commit. However, InnoDB has some optimizations to take advantage of the binary log group commit implementation.

binlog_order_commits={0|1}

This is a …

I’ll be attending this year’s US based Open Database Camp from June 8-10 in Charlotte, NC. The conference is co-located with SouthEast LinuxFest 2012.

It appears that OpenSQL Camp was renamed Open Database Camp since I see many database technologies listed on their site that do not use SQL as an access method. The final schedule of presentations shows lots of MySQL content for Friday. There is one session each for MySQL, PostgreSQL, and MongoDB on Saturday. Sunday is “unconference” style, hopefully we can get more variety in those sessions.

I love attending this type of conference because I learn how real-world users are implementing MySQL to meet their needs. It also gives me a chance to see some …

Oracle MySQL Engineer Ulf Wendel delivered yesterday a talk about his Proof of Concept at the International PHP Conference in Berlin entitled: “HTTP, JSON, JavaScript, Map and Reduce built-in to MySQL - make it happen, today.”

The presentation has been featured today on the home page of SlideShare, both into the “Hot on Facebook” and “Hot on Twitter” sections. Well done, Ulf! Especially just before the wedding…:)

Presentation abstract: See how a MySQL Server plugin can be developed to build all this into MySQL. A new direct wire between MySQL and client-side JavaScript is created. MySQL speaks HTTP, replies JSON and offers server-side JavaScript. Server-side JavaScript gets access to MySQL data and does Map&Reduce of JSON documents stored in MySQL. Fast? 2-4x faster than proxing client-side JavaScript …

Clustering databases is a mainstream technology. MySQL PHP users can take many approaches to load balancing, pooling and redirection. PECL/mysqlnd_ms is one solution. How does it handle transactions? Transactions are a challenge for every MySQL load balancer.

MySQL? Load? Clustering! Balancing! PECL/mysqlnd_ms 1.4
View more presentations from Ulf Wendel Load Balancer and transactions

A load balancer must not switch from one cluster node to another in the middle of a transactions. Unfortunately, the MySQL Protocol …