If a package manager has been used to install MariaDB, the patch upgrades, like 10.0.12 to 10.0.13, are automatic. Each package manager supports a command to upgrade the packages, and will also take care to upgrade the dependencies if needed. If no package manager is used (for example, when we are working on Windows or if we have installed the generic Linux/UNIX binaries), we will need to manually uninstall and re-install MariaDB. This is also true for minor or major version upgrades such as 10.0 to 10.1. The following commands can be used with the package managers that have been used in this chapter:

Usually, we want the new version to read our old database. So, first we need to set up the data directory, which is the directory in which the databases are written by default. A common path is /var/mysql. To use this path, we will add the following line in the configuration file:

datadir=/var/mysql

This setting will not take effect until MariaDB is restarted.

At this point, we need to upgrade the format of our databases. Since the data has been written with an older release, some modifications to the files could be necessary before the new version of MariaDB can read it. For this purpose, MariaDB distributions include a tool called mysql_upgrade. This must be done even if a package manager has been used for upgrading MariaDB.

The mysql_upgrade tool must be run when the server is running. It reads the options from the configuration files. However, if the login credentials are not written in the configuration files, the typical invocation for mysql_upgrade is the following:

mysql_upgrade -u<user_name> -p<password>

Replace <user_name> with a valid username and <password> with the corresponding password.

After running mysql_upgrade, we will be able to work again without databases!