The main tool for tuning MySQL queries is the EXPLAIN statement (https://dev.mysql.com/doc/refman/8.0/en/explain.html) and one of the hurdles on the learning curve of the EXPLAIN statement is explaining what EXPLAIN is explaining.  Basically EXPLAIN is prepended to a SELECT, TABLE, DELETE, UPDATE, INSERT or REPLACE statement.  To add to an already steep learning curve is that there are many types of EXPLAIN in MySQL.

Let Me Explain

It is very simple to add EXPLAIN at the very beginning of a query to see how the server wants to execute a query. 

EXPLAIN SELECT col1, col2 FROM my_table;

The output will show the query plan (the actual query the optimizer will instruct the MySQL server to run) and some preliminary information about how the query plan was picked among the many possible options.  Learning to use EXPLAIN to tune queries is a long process and beyond the …

Introduction MySQL is the world most popular open source database because of its reliability, high-performance, and ease of use. MySQL has been designed and optimized for transaction processing and enterprises around the world rely on it. With the introduction of HeatWave in MySQL Database Service, ...

Two or more dots in your relay log or binary log names can break replication; but worry not, it will only do it once. If you request to start again,…

The post Relay log read failure | 2 many dots can break your replication only once first appeared on Change Is Inevitable.

Database architecture and design are becoming an increasingly lost art. With new technologies and the push towards faster development cycles, people continue to take shortcuts, often to the detriment of long-term performance, scalability, and security. Designing how your application stores, accesses, and processes data is so fundamentally important, it can not be overlooked. I want people to understand that early design choices can have a profound impact on their applications. To that end, I will be exploring database design principles and practices over the next several months. I am starting with every developer’s favorite data format: JSON!

It seems that almost every database over the last few years has introduced various degrees of support for storing and interacting with JSON objects directly. While these features are designed to make it easier for application developers to write code faster, the implementations of each implementation …

This is the third episode of “Discovering MySQL Database Service“, a series of tutorials where I will show you, step by step, how to use MySQL Database Service and some other Oracle Cloud Infrastructure services.

In the previous episode we’ve created our compartment, the foundation stone, of the architecture that we will build during this Discovering MySQL Database Service journey.

In this episode, we’ll see what is a Virtual Cloud Network (VCN) and how to create one and use it.

The post Discovering MySQL Database Service – Episode 3 – Create a Virtual Cloud Network first appeared on dasini.net - Diary of a MySQL expert.

Today, we are excited to share that connection strings are available to all PlanetScale users. As a company that obsesses over making databases more accessible to developers, you might have struggled with why PlanetScale didn’t have a way to connect to your database with connection strings. And we heard you! You can now use the tools you're familiar with to connect to PlanetScale databases, whether that’s with Rails, Python, Prisma, Laravel, or any other MySQL client. Connection strings also enable you to connect to other serverless computing platforms like AWS Lambda or Vercel. Within PlanetScale, you can generate a new password and automatically get client code for many popular frameworks and languages for you to connect your PlanetScale database.

Strong passwords, never stored in plain text PlanetScale connection strings are built with security as a priority, so you can spend less time worrying if your database connections are …

Connect PlanetScale to any MySQL client with Connection Strings for a true serverless database experience.

On MySQL Database Service (aka MDS) on Oracle Cloud Infrastructure (aka OCI), when you create a new instance, you also need to set the credentials for the administrator:

Let’s focus on that account…

Please don’t forget the password, it cannot be recovered !!

First of all that account’s username has some limitations. Indeed, some names are reserved as it’s mentioned in the manual. So you could not use the following usernames:

• administrator
• ociadmin
• ocirpl
• mysql.sys
• mysql.session
• mysql.infoschema

This list can evolve, you can get the list directly from the MySQL DB System creation’s screen:

In fact, those accounts are already existing in the MySQL DB …

On MySQL Database Service (aka MDS) on Oracle Cloud Infrastructure (aka OCI), when you create a new instance, you also need to set the credentials for the administrator: Let’s focus on that account… Please don’t forget the password, it cannot be recovered !! First of all that account’s username has ...

We recently saw that .frm files have been somewhat of replaced for MyISAM tables in MySQL 8.0 (see this post).

However, what are those files ? Can they be used for something else than MyISAM tables ? … Let’s try to answer those questions and get more familiar with the .sdi files.

What does SDI stand for ?

SDI acronym stands for Serialized Dictionary Information.

As you may know already, MySQL 8.0 replaced the old way to store the metadata of tables, their structure, into the new transactional Data Dictionary (in InnoDB).

Additionally, that information is also part any InnoDB tabespace , its is appended to the tablespace, so the meta data and data are bundled …