After years of usage, your WordPress database can contain weird characters, be filled with data you don't need anymore, and so on. In this article, you will learn about SQL queries to clean up your WordPress database.
Two things to note: First, any of these queries should be preceded by a backup of your whole database. Secondly, don't forget to replace the wp_ table prefix by the prefix used on your WordPress website install, otherwise, the queries won't work.