From databasefriends.co :
http://www.databasefriends.co/2014/03/favorite-relational-database.html
While the fact that PostgreSQL is more popular than Oracle doesn't
surprise me, I always thought MySQL was way ahead of us and their claim
to be "the most popular database" was hardly arguable...
Turns out in this poll PostgreSQL has 41% and MySQL 15%.
Of course this is just a poll on a database blog. But they had 900+
answers so it's not completely meaningless :)