The most widely known query optimisation rule is that developers should always avoid SELECT *. Even when all columns are needed, they should list their names, because more columns could be created in the future. But developers find this really Continue reading How slow is SELECT * ?
Some queries always fail or never return rows. They should be eliminated to improve database performance. Continue reading Identify useless queries in MariaDB/MySQL
Comparisons are tricky when NULL values are involved. But some databases offer some special, handy syntax to solve the problem. Continue reading NULL comparisons in MariaDB, PostgreSQL, and SQLite
MariaDB 10.6 is now Generally Available! Let’s see what’s new and if it’s worth an upgrade. Continue reading A summary of MariaDB 10.6
Ignored Index are a MariaDB 10.6 feature that allows us to drop an index in production reducing the risks. Continue reading MariaDB Ignored Indexes
Having many indexes in our databases comes with a cost. It is good to periodically eliminate duplicate and unused indexes. Continue reading Finding Duplicate Indexes and Unused Indexes in MariaDB/MySQL
MariaDB/MySQL replication filters may be useful, but they come with some risks that Database Administrators should be aware of. Continue reading The risks of replication filters in MariaDB and MySQL
Aria pagecache is used to cache frequently read index blocks, reducing the accesses to disks. Let’s see how to check if its size is adequate. Continue reading Sizing Aria Pagecache
Ansible can skip certain tasks by default. This can be useful when we automate databases. Let’s see how to do it and why. Continue reading How to skip an Ansible task by default
An oversized InnoDB buffer pool will consume too many resources and can be slower than necessary. Let’s see how to check if we can shrink it. Continue reading Can we shrink InnoDB Buffer Pool?