Doubt no more than mySQL is enterprise class

The open source database based in Finland started from nothing, and the argument against it has always been that it lacks the features and functionality enterprises need, that it's three, or two, or at least a year behind Oracle in vital respects.

I don't think you can make that argument any more. Booking.Com has gotten it.

Booking.Com bills itself as Europe's largest online hotel reservation system. The site is available in 15 languages, and handles 30,000 properties in 8,000 destinations worldwide. Its strategy is to open processing centers in several locations, like Cape Town, Warsaw and Dubai.

Booking.com says it's processing "tens of thousands" of reservations a day, but more important that it's growing exponentially.

Yet they commited to mySQL. Not Oracle, not DB2, not SQL Server, and not Ingres. Now it's always possible these people are out of their minds, or just enamored of freeware, but I doubt it.

I'd say Oracle has a serious problem.