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The latest from the MySQL community

Ideas, releases, practical guides, and perspectives from the people building with MySQL.

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Indexing JSON Data in MySQL

Storing JSON in a relational database is something developers have done for quite some time. There are a variety of reasons why you would want to store JSON in a database table – user preferences and configuration data are two good examples. The JSON Data Type was introduced to MySQL in version 5.7.8. This data type allows […]

COUNT(*) vs COUNT(col) in MySQL

Looking at how people are using COUNT(*) and COUNT(col), it looks like most of them think they are synonyms and just use what they happen to like, while there is a substantial difference in performance and even query results. Also, we find a difference in execution on InnoDB and MyISAM engines.

NOTE: All tests were applied for MySQL version 8.0.30, and in the background, I ran every query three to five times to make sure that all of them were fully cached in the buffer pool (for InnoDB) or by the filesystem (for MyISAM).

Count function for Innodb engine:

Let’s have look at the following series of examples for InnoDB engine:

CREATE TABLE count_innodb (
  id int(10) unsigned NOT NULL AUTO_INCREMENT,
  val_with_nulls int(11) default NULL,
  val_no_null int(10) unsigned NOT NULL,
  PRIMARY KEY idx (id)
) ENGINE=InnoDB DEFAULT CHARSET=latin1;

(mysql) > select count(*) from count_innodb; …
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How to import data from Microsoft SQL Server to MySQL HeatWave Database Service

After having see how we can import data from PostgreSQL and Amazon Redshift, this time we will see how we can export data from Microsoft SQL Server and import it into MySQL HeatWave Database Service in OCI. This time we will use something extra (for fun but also because it’s practical): OCI Object Storage ! […]

OpenLampTech issue #60 – Substack Repost

Thank you so much for reading OpenLampTech and making it the success it is today. Wow! 600 developers reading each week! I am humbled to say the very least.

The Newsletter for PHP and MySQL Developers

Receive a copy of my ebook, “10 MySQL Tips For Everyone”, absolutely free when you subscribe to the OpenLampTech newsletter.

In OpenLampTech issue #60, we are looking at some fantastic articles covering:

  • Laravel Eloquent and Query Builder tips
  • Drupal’s updated CKEditor 5
  • How Symfony powers Drupal
  • Best SQL Editors
  • WooCommerce Payment Gateways
  • And much more

Want to help OpenLampTech be a success …

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How to import data from Microsoft SQL Server to MySQL HeatWave Database Service

If you have data stored in a Microsoft SQL Server database and you want to import it into MySQL HeatWave Database Service in OCI, you can use the procedure described in this article.

How to speed up a Mysql replica?

There are several ways you can try to speed up a MySQL replica. Here are some ideas:

How To Generate Test Data for Your Database Project With Python

If you need test data for the database of your project, you can get a dataset from Kaggle or use a data generator. In the first case, if you need to process the data before inserting it into the database, you can use Pandas, a widely used Python library for data analysis. This library supports different formats, including CSV and JSON, and it also provides a method for inserting data into a SQL database.

If you choose a data generator instead, you can find one for MySQL in one of the repositories on our Percona Lab GitHub account. Are you using other database technologies? You can follow the guides I already published where I explain how to create your own data generator for …

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MySQL InnoDB Redo Log Archiving

When performing physical backup on system that are heavily used, it can happen that the backup speed cannot keep up with the redo log generation. This can happen when the backup storage is slower than the redo log storage media and this can lead in inconsistency in the generated backup. MySQL Enterprise Backup (aka MEB) […]

MySQL InnoDB Redo Log Archiving

What is MySQL InnoDB Redo Log Archiving ? How does it work ? Discover this important MySQL InnoDB feature reading this blog post.

Live Migration from Azure Database for MySQL to MySQL HeatWave Database Service on OCI

In this article we will see how to perform a live migration from Azure/MySQL to OCI/MySQL HeatWave. As Azure allows public connections directly to the database, this is what I will use to migrate and replicate the data between both clouds. Also, since this content is focused on data migration, I won’t explore all the […]