No experience with either, but I've used MySQL for moderately massive DBs.
Had one where we were adding 1GB every 20 minutes and, at the same time, doing some moderately sophisticated data mining of that data. Granted, was on machine with quad processor and 8GB of RAM with about 80% dedicated to MySQL.
So even freebie and easy to use MySQL may be up to your task.
An optimist sees the glass as half full.
A pessimist sees the glass as half empty.
A realist drinks it no matter how much there is.