complement, you can access mysql via hadoop.
Hadoop is a framework, a big map/reduce system.
you basically serialize your object (binary java form) distribute them with the data over a large cluster, and then get the resultsets back.
I would have to read up on it, I just helped one data-lead-engineer using it with apache-spark for their job scheduling system with yarn.
you basically pass functions and data around, and you have to think highly functional.
So no they are different things you can add a storage but in general it's a process- clustering-system