@garius And their flagship database is an enormous pile of Crap. Many people feed their families by knowing its quirks and difficulties, but I'd rather be productive.
To give you just one example: Oracle SQL HAS NO BOOLEAN DATA TYPE. The official recommendation is to use a 1 char field. What goes into that? Well, who knows? "Y/N" ? "y/n"? "O/N" if you're french? "1/0"?
In many shops, the result is supposedly boolean fields that contain 3, 5, even 7 different values. Yikes.