It looks like Amazon's migrating away from Oracle pretty aggressively, however. https://www.cnbc.com/2018/08/01/amazon-plans-to-move-off-ora...
Re:Postgres 11 – A First Look
by reitanqild on Saturday September 22, 2018 @08:57AM
(#18045804)
That's weird.
But maybe at their scale even Oracle can be made tolerable.
That, and they have some serious leverage in negotiations.
(I used to deal with Oracle DBs a lot a few years ago but thankfully not anymore.)
Amazon actually uses a lot of Oracle with some scattering of MySQL.