First I want to thank everyone who attended my December 5, 2019 webinar “Introduction to MySQL Query Tuning for DevOps“. Recording and slides are available on the webinar page.

Here are answers to the questions from participants which I was not able to provide during the webinar.

Q: How to find stored execution plans and optimizer metadata stored in mysql data dictionary (i.e. PS, IS, sys schema)?

A: The Optimizer creates the query execution plan each time when MySQL Server executes the query. These plans are never stored.

However, some information, used by the optimizer, to create the execution plan, is stored and available. It includes.

…

When you have multiple database servers working together as nodes in a cluster, it’s beneficial to understand how data consistency is established. In this post, we’re going to take a look at the various cluster consistency levels that you can choose from within InnoDB Group Replication and see how they impact data flow and failure recovery.

Let’s start with a quick refresher on what data consistency is. In a nutshell, consistency is just a way of thinking about how data is duplicated across multiple nodes in a cluster. If you write a row of data to one node, that data is not considered to be consistent within the cluster until it has been written to all of the other participating nodes. Without consistency, it’s possible to write data to one node in the cluster but not see it immediately when reading from another node in the cluster. In some cases, the aforementioned scenario, better known as eventual consistency, is acceptable but …

Slow queries, inefficient queries, or long running queries are problems that regularly plague DBA's. They are always ubiquitous, yet are an inevitable part of life for anyone responsible for managing a database. 

Poor database design can affect the efficiency of the query and its performance. Lack of knowledge or improper use of function calls, stored procedures, or routines can also cause database performance degradation and can even harm the entire MySQL database cluster. 

For a master-slave replication, a very common cause of these issues are tables which lack primary or secondary indexes. This causes slave lag which can last for a very long time (in a worse case scenario).

In this two-part series blog, we'll give you a refresher course on how to tackle the maximizing of your database queries in …

The schedule of the preFOSDEM Day is now available !

We had a lot of proposals to deal with. Also this is a MySQL event where we, the MySQL Team has the possibility to show to you, our Community, all what we have working on to improve MySQL but also new stuff. We also invite some of our friends from the MySQL Community to talk about their experience.

I think we did a good selection and propose you new content. We are extremely happy to have Saverio Miroddi from TicketSolve talking about MySQL 8.0, Uber talking about InnoDB Cluster, and Facebook about Binlog.

As you can see, we will have 2 rooms, where one will be dedicated mostly to SQL and Optimizer topics but also tutorials.

You can also see that this year we also want to put some spot lights to MySQL NDB Cluster. You will see what is it, how is it used and what’s new. We will also have 2 community speakers sharing their MySQL NDB knowledge: Giuseppe Maxia, …

can we add particular columns and rows value in excel file using php

Hello, i’m one of your followers. Thank you for your tutorials.
I’m trying to build a table with bootgrid based on your example ”simple bootsgrid, add, edit”, i would resize columns at my own width but it’s don’t work. Please can you help me? How can i do it?

The innodb_io_capacity and innodb_io_capacity_max are often misunderstood InnoDB parameters. As consultants, we see, at least every month, people setting this variable based on the top IO write specifications of their storage. Is this a correct choice? Is it an optimal value for performance? What about the SSD/Flash wear leveling?

Innodb_io_capacity 101

Let’s begin with what the manual has to say about innodb_io_capacity:

“The innodb_io_capacity variable defines the number of I/O operations per second (IOPS) available to InnoDB background tasks, such as flushing pages from the buffer pool and merging data from the change buffer.“

What does this mean exactly? …

This talk uncovers which tools/plugins/settings you need to use to comply with PCI/DSS when using MySQL. Gain a solid grasp of the possibilities, as well as the limitations, MySQL offers to someone looking to become PCI/DSS certified.

Please join Percona Support Engineer Carlos Tutte on Friday, Dec 20, 2 – 3 pm EST to learn the pros and cons of PCI/DSS Certification with MySQL.

Register Now

If you can’t attend, sign up anyways we’ll send you the slides and recording afterward.

When we think about the cloud, often we consider many of the benefits: scalability, elasticity, agility, and flexible pricing.  As great as these features are, security also remains a business-critical concern. In an on-premise environment, every aspect of security is owned by you.  Looking at the database layer specifically, these include (but are not limited to):

• Data encryption
• Database access control
• Network security
• OS security (both host and guest if in VM environment)
• Physical security

When done properly, that entails a significant amount of work and generally cost.  In the cloud, those aspects are all still relevant and necessary for proper security.  However, under the shared responsibility model, some of that work is offloaded from you and shifted to the cloud provider.  Let’s look at what that model entails and how it is realized …

Hello! In MySQL 8.0.17, we made an observation in the well-known TPC-H benchmark for one particular query. The query was executing 20% faster than in MySQL 8.0.16. This improvement is because of the “antijoin” optimization which I implemented. You can find out more in my blog post on mysqlserverteam.