You must be a salesperson. I'm not a technology zealot, but Oracle is by far the most superior product in the market for mid ot large size datasets serving mid to large size queries (carefully chosen words ;) ). I realize you can polish and sell a turd, but Oracle's scaling, robustness, and attention to detail regarding the optimization of its core engine, is what sells it, and has for the past ~30 years.
Now MS has the exact same yammering salespeople who drive me nuts when they tout the strength of their package, but I've explored it with the intimate detail that only a DBA can.
Read my lips: Its crap.
When you start to pull away from the sales pitch, super easy install, and drop and go fascade, you quickly unveil a half working SQL engine, a busted backup model, and an internal engine that turns itself into muck heaven forbid if anybody hit it with any sort of large query.
Sorry, its the Oracle DBMS engine that has made them the big bucks. Don't even get me started on Oracle forms and reports.