Mysterious warning Recently, I was involved in an investigation whose goal was to find out the reason for a warning message like this: [crayon-6790b5b2ced83782454901/] The message looks clear, isn’t it? Well, the problem was that this particular table had not been changed for years, and so no DDL (ALTER) query was involved here. Moreover, there […]

In current times, there is a high degree of focus on ensuring the availability and recovery of your production data. This can be challenging at times when using DBaaS solutions in the public cloud space, for example, when using AWS Aurora. Relying solely on a single cloud provider for database services can pose significant risks. […]

Group replication is a fault-tolerant/highly available replication topology that ensures if the primary node goes down, one of the other candidates or secondary members takes over so write and read operations can continue without any interruptions. However, there are some scenarios where, due to outages, network partitions, or database crashes, the group membership could be broken, or we end […]

The usage of MySQL Router as a Middleware/Proxy/Router has increased along with the rise in MySQL InnoDB Cluster usage. While it is still relatively easy to use in production, monitoring it to stay informed about its current status is essential. This blog post will cover how to check and monitor MySQL routers, routes, and other […]

A couple of weeks ago, my colleague Marco Tusa published an important announcement titled “Do Not Upgrade to Any Version of MySQL After 8.0.37.” The announcement highlighted a critical issue in MySQL 8.0.38, MySQL 8.4.1, and MySQL 9.0.0 that caused database server crashes. Good news! The upcoming minor releases for the community edition of MySQL and […]

pt-online-schema-change is an amazing tool for assisting in table modifications in cases where ONLINE ALTER is not an option. But if you have foreign keys, this could be an interesting and important read for you. Tables with foreign keys are always complicated, and they have to be handled with care. The use case I am […]

MySQL 9.0 is an Innovation Release, but as you may have read in my Quick Peek, I found little innovation. However, one new item caught my eye, and it could be a way to track query performance. MySQL 9.0 EXPLAIN enhancement Here is the syntax that will be referenced in the post. {EXPLAIN | DESCRIBE […]

In this article, we will demonstrate how to have a single MySQL database user account that can connect from specific hosts. We would usually implement it by creating separate user accounts with the same username but different hosts/IPs like <USER>@<HOST1>, <USER>@<HOST2> …. <USER>@<HOSTn>. Then, give those users the same grants(privileges/roles) and settings(password, SSL, etc). Instead […]

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 […]

You probably missed the news, but… PT-1751: Adds –where param to pt-online-schema-change This brings the possibility to perform what I would call an “inverted purge” because you are not actually purging rows from your multi-terabyte table, but rather, you copy the small percentage of rows you want to keep to a new table and then […]