But not MySQL. Now let's see, which one might I be thinking of?
MySQL lacks many features big companies want for using it with applications that are central to their business, like manufacturing or finance software from companies like SAP.
So, what kind of database would SAP use? Oh, maybe [link|http://www.sapdb.org/sap_db_downloads.htm|SAPDB]. That's the download page. Look to the right. Yes, that's a link to "GNU License".

So to answer the question: Yes, "an Open-Source Database" does have "features big companies want ... companies like SAP."