MySQL is certainly a powerful open source database management system, but even the most robust engine struggles when queries take an eternity to execute. For DBAs and developers, improving MySQL query performance is an ongoing goal. Efficient query performance is crucial for ensuring the smooth operation and optimal user experience of applications powered by MySQL databases. When businesses rely h

Warning! Recently, Jean-François Gagné opened a bug on bug.mysql.com #115517; unfortunately, the bug is now private. However, the bug looks quite serious. We at Percona have performed several tests and opened the issue PS-9306 to investigate the problem. In short, what happens is that if you create a large number of tables, like 10000, the […]

Some of our Percona Support customers report performance degradation after a major MySQL upgrade, and there can be many different reasons for this. These days, the most common major upgrade is from MySQL 5.7 (which recently reached EOL) to 8.0, and I am going to emphasize one important case that affects many database instances. Range […]

Have you ever read a news story about a major company experiencing a data breach that exposed millions of customer records? These breaches can be devastating, causing significant financial losses, reputational damage, and even legal repercussions. Unfortunately, MySQL databases, one of the most popular relational database management systems, is at the heart of many critical applications, making it

MySQL 8.4 has now been officially released, and this is a quick review of what is in the release notes. This is momentous as it is designated a Long-Term Support (LTS) release. Various 8.0 releases introduced material changes that impacted speed and stability, causing hair-pulling and swearing among those affected. Please note this is a first peek at the release notes, and comments in italics are

If you have enough experience with MySQL, it is very possible that you stumbled upon an unusually slow SELECT COUNT(*) FROM TABLE; query execution, at least occasionally. Recently, I had a chance to investigate some of these cases closer, and it stunned me what huge differences there can be depending on the circumstance given the very same table. As the problem turned out to be much more complex t

Are you planning to upgrade your PostgreSQL database but feeling overwhelmed by the complexity of the task?  We have something that will make your life much easier. Introducing The Ultimate PostgreSQL Upgrade Checklist – designed to guide both seasoned and new DBAs and developers through the intricate process of a PostgreSQL upgrade. Why you need this PostgreSQL upgrade checklistUpgrading your Pos

Oracle recently made their quarterly releases with MySQL 8.0.35 and MySQL 8.2. This blog post is a quick look at the release notes to see what these new versions bring to the community. You’ll want to keep an eye on the deprecations in particular because some long-accepted behavior, including wildcards, will change eventually. We get 83 and 50 bug fixes, respectively. We also get 17 and 33 depreca

Sometimes, there is a need to update the table and index statistics manually using the ANALYZE TABLE command. Without going further into the reasons for such a need, I wanted to refresh this subject in terms of overhead related to running the command on production systems. However, the overhead discussed here is unrelated to the usual cost of diving into table rows to gather statistics, which we c

Whenever you install your favorite MySQL server on a freshly created Ubuntu instance, you start by updating the configuration for MySQL, such as configuring buffer pool, changing the default datadir director, and disabling one of the most outstanding features – query cache. It’s a nice thing to do, but first things first. Let’s review the best practices we usually follow in Managed Services before

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This blog is in reference to our previous ones for ‘Innodb Performance Optimizations Basics’ 2007 and 2013. Although there have been many blogs about adjusting MySQL variables for better performance since then, I think this topic deserves a blog update since the last update was a decade ago, and MySQL 5.7 and 8.0 have been released since then with some major changes. These guidelines work well for