Cayenne database

Greetings! I am new with the platform cayenne and my group will use this as our IoT platform for our thesis. We were wondering if what database is used in the cayenne since we need to state what database allows to have the downloadable data. We were hoping to know about this database to help us for the success of our study. Thank you and God Bless!

I’m not sure what the database type is, but regardless, Cayenne doesn’t allow direct database queries.