Historically, Mysql was "faster" than Postgres (it's called Postgres or PostgreSQL) in the same way that a bicycle without brakes was faster at going down hills. These days, Postgres is a lot faster, and Mysql, with InnoDB, has things like transactions that make it an actual database. I've always been partial to Postgres because it was an actual database with more features and without any of the licensing weirdnesses of Mysql.