lefred's blog

There Are 10 Types of People in the World....

MySQL 8.0: if I should optimize only one query on my application, which one should it be ?

Answering this question is not easy. Like always, the best response is “it depends” ! But let’s try to give you all the necessary info the provide the most accurate answer. Also, may be fixing one single query is not enough and looking for that specific statement will lead in finding multiple problematic statements. The most consuming one The first … Read More

MySQL 8.0 Memory Consumption on Small Devices

Recently, PeterZ pointed a huge difference in memory usage of MySQL 8.0 compare to MySQL 5.7. This can be an issue for small instances if the same configuration for buffers like the buffer pool are not changed. As explained in Peter’s article, this can lead to the awakening of the so feared OOM Killer ! MorganT, pointed accurately in his … Read More

Migrate from a single MySQL Instance to MySQL InnoDB Cluster using CLONE plugin

When somebody wants to migrate from a single MySQL instance to a full HA solution using MySQL InnoDB Cluster, the best solution to reduce the downtime is to use asynchronous replication and switch database only once at a certain point in time when everything is ready. This is almost what I explained already in this post. The most difficult part … Read More

MySQL 8.0 and wrong dates

In MySQL 8.0, when using invalid values for date data types, an error is returned. This was not the case in 5.x versions.

MySQL InnoDB Cluster, automatic provisioning, firewall and SELinux

You may have noticed that in many of my demos, I disable firewall and SELinux (I even use –initialize-insecure sometimes 😉 ). This is just to make things easier… But in fact enabling iptables and SELinux are not complicated.