This blog was published in April of 2021 and updated in April of 2024.In past versions of MySQL, there was often an ‘upgrade dance’ that had to be performed in starting up a newly upgraded MySQL instance with the previous version configuration file. In some cases a few deprecated options might no longer be supported […]

Any Galera documentation about limitations will state that tables must have primary keys. They state that DELETEs are unsupported and other DMLs could have unwanted side-effects such as inconsistent ordering: rows can appear in different order on different nodes in your cluster.If you are not actively relying on row orders, this could seem acceptable. Deletes […]

You know about MySQL; we know about MySQL. After all, it’s been the most popular database system for years now. And now that we have that out of the way, on to the more important stuff!Because MySQL is so popular, you might be considering migrating your database to MySQL Community Edition or MySQL Enterprise. If […]

Historically, MySQL does not require explicit primary key defined on tables, and it’s like that by default till this day (MySQL version 8.3.0). Such a requirement is imposed through two replication methods, though: Group Replication and Percona XtraDB Cluster (PXC), where using tables without a primary key is not allowed by default. There are many […]

To be honest, the comparison between the two MySQL distributions is not something that excited me a lot. Mainly because from my MySQL memories, I knew that there is not a real difference between the two distributions when talking about the code base.To my knowledge the differences in the enterprise version are in the additional […]

Are your MySQL users using ‘password’, ‘s3cr3t’, or ‘thebossisajerk’ as their passwords? Easy-to-guess passwords can be disastrous to the security of your data, but there is a way to exclude inappropriate words or phrases from being used. The first step is to compile a list of words and phrases you want to exclude, and that […]

It is a known good practice to keep only necessary indexes to reduce the write performance and disk space overhead. This simple rule is mentioned briefly in the official MySQL Documentation:https://dev.mysql.com/doc/refman/8.0/en/optimization-indexes.htmlHowever, in some cases, the overhead from adding a new index can be way above the expectations! Recently, I’ve been analyzing a customer case like […]

In this blog post, we will discuss how to validate at the operating system level the effects of changing the innodb_flush_method to variations other than the default (particularly for O_DIRECT which is most commonly used) and the use of innodb_use_fdatasync.IntroductionFirst, let’s define what the innodb_flush_method parameter does. It dictates how InnoDB manages the flushing of data […]

Oracle recently released MySQL 8.0.36 and MySQL 8.3, and this is a perusal of the release notes to determine what is new, what is in the seventy-three bugs fixed, and what has changed in the three months since the last releases. Comments in italics are my own and do not reflect the view of anyone […]

One of our customers wants to create a table having a column of data type TEXT with the default value, but they encountered an error: [crayon-661430a432b94245573814-i/]. It seems reasonable at first glimpse, as we know that each BLOB, TEXT, GEOMETRY, or JSON value is represented internally by a separately allocated object. This is in contrast […]