In addition to databases that store websites data, Plesk has its own
database for storing information about customer and resellers accounts,
their subscriptions, and so on. This database is called psa and
located on the local MySQL server. The local MySQL server is installed
together with Plesk and is required for Plesk functioning. However,
since version 11.5, you can replace the local MySQL server with an
alternative database server, for example, MariaDB
(https://mariadb.org) or Percona Server
Below in this section we will explain how to replace MySQL with MariaDB.
For other MySQL replacements, instructions are basically the same.