InnoDB默认的全文索引parser非常合适于Latin，因为Latin是通过空格来分词的。但对于像中文，日文和韩文来说，没有这样的分隔符。一个词可以由多个字来组成，所以我们需要用不同的方式来处理。在MySQL 5.7.6中我们能使用一个新的全文索引插件来处理它们：n-gram parser.

什么是N-gram？

在全文索引中，n-gram就是一段文字里面连续的n个字的序列。例如，用n-gram来对”信息系统”来进行分词，得到的结果如下：

N=1 : '信', '息', '系', '统';
N=2 : '信息', '息系', '系统';
N=3 : '信息系', '息系统';
N=4 : '信息系统';

…

It’s been almost a year since I benchmarked MariaDB and MySQL on our good old 4 CPU / 32 Cores / 64 Threads Sandy Bridge server. There seem to be a few interesting things happened since that time.

• MySQL 5.6.23 peak throughput dropped by ~8% compared to 5.6.14. Looks like this regression appeared in MySQL 5.6.21.
• 10.0.18 (git snapshot) peak threads increased by ~20% compared to 10.0.9 and reached parity with 5.6.23 (not with 5.6.20 though).
• 10.1.4 (git snapshot) and 5.7.5 are the champions (though 10.1.4 was usually 1-5% faster). Both have similar peaks @ 64 threads. They seem to be pushing this system limits, since both have capacity to scale more.
• 5.7.6 has serious (~50%) scalability regression compared to 5.7.5. There is heavy LOCK_plugin mutex contention, which seem to be caused …

Thu, 2015-03-26 07:48russelljtdyer

For my new book, Learning MySQL and MariaDB, Monty Widenius, one of the founders of MySQL and MariaDB, graciously contributed a Foreword. It's about six pages long and an interesting read for those who are familiar with MySQL and MariaDB. Of particular interest to newcomers to MariaDB, is the excerpt below on his perspective of MariaDB and his vision for its future, as well as MySQL.

Excerpt from Foreword of Learning MySQL and MariaDB (O'Reilly 2015)

"Regarding my hopes and expectations for the MariaDB database system, I’m working at the foundation to ensure that we get more companies actively involved in the development of MariaDB. That’s something …

Percona Live is the premier event for the MySQL ecosystem. It is being held in Santa Clara this year, April 13 - 16. If you are not already registered, use the code Vividcortex20 to receive a 20% discount.

We will be exhibiting, and Baron Schwartz will be speaking on Encrypting Data in MySQL with Go on April 16th at 12:50.

We look forward to seeing you!

On servers that are into the swap file and have multiple processes running, I often wonder if it’s MySQL that is in the swap or some other process.  With Linux this is a fairly easy thing to figure out.  Below is the format of a command to do just that:

echo 0 $(cat /proc/`pidof process`/smaps | grep TYPE | awk '{print $2}' | sed 's#^#+#') | bc

In the above command, TYPE refers to what type of Memory you want to examine.  Below are some of the options for this value:

Decoupling Statement Digests From Performance Schema

MySQL Statement Digests are a feature originally introduced as part of the MySQL Performance Schema in MySQL 5.6 to aggregate statement statistics based on the normalized statements executed within the server (for additional info, see here).

Statement Digests were previously only available as a part of the MySQL Performance Schema. In other words, they were only …

Atlassian apps are widely used by development teams to facilitate software development and collaboration. For larger teams who require enterprise-grade tools, you might want to host the applications in your own data center and cluster them for high availability and performance. 

In this blog post, we are going to deploy a redundant active-passive setup for JIRA with clustered MySQL and NFS shared storage. Note that some Atlassian applications (JIRA, Confluence and Stash) already has built-in clustering support, and these require you to have a Data Center license. In this blog, we will show you how to cluster the regular/standalone JIRA server product by deploying an active JIRA server with an additional passive stand-by instance for failover purposes.

The following is our architecture diagram:

…

One year ago, I blogged about Evaluation and Online Migration of MySQL 5.6 GTIDs.  At that time, we setup the following test environment where:

A is a production master with GTIDs disabled, D to Z are standard slaves with GTIDs disabled, B is an intermediate master running my recompiled version of MySQL implementing the ANONYMOUS_IN-GTID_OUT mode (see the details my previous post), C is a slave

Founded in 2004 to help people find great local businesses, Yelp has some 135 million monthly unique visitors. With those traffic volumes Yelp’s 300+ engineers are constantly working to keep things moving smoothly – and when you move that fast you learn many things.

Fortunately for the global MySQL community, three Yelp DBAs will be sharing what they’ve learned at the annual Percona Live MySQL Conference and Expo this April 13-16 in Santa Clara, California.

Say “hello” to Susanne Lehmann, Jenni Snyder and Josh Snyder! I chatted with them over email about their presentations, on how MySQL is used at Yelp, and about the shortage of women in MySQL.

***

Tom: Jenni, you and Josh will be co-presenting “ …

We’ve heard lots in recent years about Big Data and the alternative models of data management and processing, like Hadoop and NoSQL. But truth be told, relational databases are still the workhorses of most of today’s small and medium sized businesses. Relational DBs date back over 40 years and SQL skills are fairly common, and they’re known to be highly secure.

MySQL is the world’s second most popular relational database management system (RDMS) and is the most popular open-source version of the database. It’s easily accessible and is often known to be part of the LAMP web development stack, standing for the ‘M’ in the acronym of popular tools, along with Linux, Apache, and PHP/Perl/Python. The fact that MySQL is free, easy to setup and scales fast are some of the main reasons why it’s the best match for many SMBs.

…