I'd be interested to see how many large companies have the courage to switch their databases after they've reached a "mature" stage as a company. My guess is a

I'd be interested to see how many large companies have the courage to switch their databases after they've reached a "mature" stage as a company. My guess is a very small number have the technical expertise in order to make it worth doing in the first place, meaning in many cases the database the CEO picked when it was him in a basement learning to code for the first time is the one used in production many years later.