Occasionally at conference or a Meetup, someone will approach me and ask me for help with a MySQL problem.  Eight out of ten times their difficulty includes a sub query. "I get an error message about a corrugated or conflabugated sub query or some such,"  they say, desperate for help.  Usually with a bit of fumbling we can get their problem solved.  The problem is not a lack of knowledge for either of us but that sub queries are often hard to write. 

MySQL 8 will be the first version of the most popular database on the web with Common Table Expressions or CTEs.  CTEs are a way to create temporary tables and then use that temporary table for queries. Think of them as easy to write sub queries!

WITH is The Magic WordThe new CTE magic is indicated with the WITH clause.

mysql> WITH myfirstCTE 
      AS (SELECT * FROM world.city WHERE …

Thank you for attending my webinar on Wednesday, December 20, 2017, InnoDB Performance Optimization. In this blog, I will provide answers to the Q & A for the webinar.

Are the T2 CPUs similar to the M4 series?

I would expect them to be similar. Amazon does not disclose what specific version of CPUs they use for T2 instances. More details are available here.

Delay in spinlock code is pretty old code. Need to optimize based on today’s CPU? Your views?

There have been a number of improvements to the InnoDB Spinlock code during the last few years. For example, using CPU wait …

There are two new MySQL books both from Apress Press. One is an in depth master course on the subject and the other is a quick introduction.


ProMySQL NDB Cluster is subtitled Master the MySQL Cluster Lifecycle and at nearly 700 pages it is vital resource to anyone that runs or is thinking about running NDB Cluster. The authors, Jesper Wisborg Krogh and Mikiya Okuno, have distilled their vast knowledge of this difficult subject in a detail packed but easily readable book.  MySQL Cluster is much more complex in many areas than a regular MySQL server and here you will find all those details. If you run MySQL NDB Cluster then you need this book. The partitioning information in chapter 2 is worth the price of the book alone.  I am only a third of the way …

Join Percona Chief Evangelist Colin Charles as he covers happenings, gives pointers and provides musings on the open source database community.

I think the biggest news from last week was from cPanel – if you haven’t already read the post, please do – on Being a Good Open Source Community Member: Why we hesitated on MySQL 5.7. cPanel anticipated MariaDB being the eventual replacement for MySQL, based on movements from Red Hat, Wikipedia and Google. The advantage focused on transparency around security disclosure, and the added features/improvements. Today though, “MySQL now consistently matches or outpaces MariaDB when it comes to development and releases, which in turn is increasing the demand on us for providing those upgraded versions of MySQL by our users.” And …

Fill out a quick survey on your cloud data plans.

Today, keeping your enterprise agile and flexible is not just an advantage, it is a requirement. Many of the systems and processes once controlled by businesses onsite are moving offsite to “service” models. This includes Platform as a Service (PaaS), Software as a Service (SaaS), Infrastructure as a Service (IaaS), Database as a Service (DBaaS), etc.

These services are usually referred to as being in the cloud. The enterprise using the service doesn’t maintain or manage the infrastructure of the service in question.

Migrating database workloads to the cloud can be a vital part of improving customer experience, gaining deeper business insights and increasing efficiency. More enterprises are …

Important notice: With this release, we have changed the registration keys. As usual, the new keys are available for registered users from our Customer Portal.

Monyog MySQL Monitor v8.4.0 adds more alert and logging options and enhances the MONyog API. Further, we redesigned the settings page and a number of bugs were fixed.

Changes as compared to Monyog MySQL Monitor v8.3.2 include: Features:

Added more notification channels (Slack and Pagerduty) for Monyog alerts. (Read more) Option to write Monyog alerts in the Syslog of the machine where Monyog is installed. This option is only available for Linux. Option to edit the subject line for Monyog alerts. Added MONyog API to disable notification for a monitor based on a server/tag. ( …

Join Percona’s Chief Evangelist, Colin Charles as he presents 2017 Year in Review for Open Source Database Software on Wednesday, December 13, 2017 at 7:00 am PST / 10:00 am EST (UTC-8).

Register Here

2017 is soon coming to an end, and it’s good to pause and take a look at the past year to see the impact of new software release. Colin will discuss the changes, growth and trends that have affected software producers and enterprises using open source.

Key topics will include:

• How has the software supply chain landscape …

The story of Steven Mapes, an experienced software developer who has been using SQLyog MySQL GUI since 2002.

We were so thrilled to speak with Steven Mapes for two simple reasons. One, he is an ardent user of SQLyog. Two, he has been using the tool since 2002 (we had released the GA version of SQLyog in 2002). And, it is users like Steven who make the product successful with their constant support and feedback that keeps us going.

We go down memory lane and learn some interesting facts about SQLyog that made Steven stick with the tool for more than a decade.

Steven Mapes is a self-employed software solutions provider who develops web-based polyglot solutions for clients often hosted within the cloud since 2012. Before it, he was the Head of IT for Moko Social Media in the UK. When asked about how he came across SQLyog and the need to use the tool, Steven says,”My first exposure to SQLyog was back in 2002 when the …

Amazon Web Services (AWS) is a cloud platform that offers a wide variety of services including computing power, database storage, content delivery and other functionality that targets businesses of all sizes. One of their database solutions includes the Amazon Relational Database Service. Amazon RDS includes a number of popular RDBMSes, including Amazon Aurora, PostgreSQL, MySQL, MariaDB, Oracle, and Microsoft SQL Server, as well as tools to manage your databases and monitor their performance.

Despite the wide range of metrics available within the Amazon RDS console, there are some very good reasons for using your own monitoring tool(s) instead or in addition to those offered by Amazon RDS. For example, familiarity with your own tool(s) or access to features that Amazon RDS does not provide would constitute two persuasive reasons for employing a local tool.

With traditional software monitoring platforms such as Monyog still enjoying …

JSON data is a wonderful way to store data without needing a schema but what about when you have to yank that data out of the database and apply some sort of formatting to that data?  Well, then you need JSON_TABLE.

JSON_TABLE takes free form JSON data and applies some formatting to it.  For this example we will use the world_x sample database's countryinfo table.  What is desired is the name of the country and the year of independence but only for the years after 1992.  Sound like a SQL query against JSON data, right? Well that is exactly what we are doing.

We tell the MySQL server that we are going to take the $.Name and $.IndepYear key's values from the JSON formatted doc column in  the table, format them into a string and a integer respectively, and alias the key value's name to a table column name that we can use for qualifiers in an SQL statement.

 …