I know it's a pretty popular view to skewer Oracle, considering how much money they make from licensing and how little they seem to do.
From the other side, I work at a medium-sized consultancy that handles Oracle databases as well as other products. I work with open source, big data technologies (Hadoop, Mongo, Cassandra), and I talk to some of our top Oracle guys sometimes. Oracle does everything, and it does it damn-near automatically - look at the concepts guide (http://docs.oracle.com/cd/E11882_01/server.112/e40540.pdf) if you want to see how many types of JOIN an Oracle DB can choose from. Exadata has more, I think, and half the performance stuff isn't even documented, it's just buried in query plans. I'll tell an Oracle guy, "hey, we just got hash-bucket joins", or skip scans, or some other enhancement, and it's like the OSS competition is still in the 90s compared to what Oracle can do.
You can complain that Oracle charges a lot of money, but in a lot of cases it's NIH syndrone. Drop in Postgres instead, then spend 6 months tuning it, or spend the difference buying extra hardware to scale out. Roll your own ERP, and forever have a small dev team of 4 guys who cost you half a million dollars to support it, because you didn't want to buy off-the-shelf, because your pride as a developer stops you from learning someone else's tool.