Which database?

We have to launch a new service in my company with a big database.

And I currently don't have that much knowledge.

We did a small preview of the service and our biggest table had more than 2 100 000 rows.
Our second biggest table had 300 000 rows.

Currently our database if only 15GB but the final one will be at least 75 times bigger.

And no need to say that we need to access to our database very quickly and to run queries quickly as well.

What's your advice about our infrastructure (One big server or several servers) and what database system should we use ?

I would recommend trying PostgreSQL to be honest. You can always move away later but that's a good place to start. It's free. It's not a db specializing in running code written for other db's (like MySQL is). It is enterprise-grade. It is advanced and you can take the features it offers and go very far. With regard to advanced data modelling it is on a par with the best commercial RDBMS's though in some other areas it is not there yet.

It is hard to know though given how vague your requirements are.

The key thing you always need to keep in mind is that your key constraints are:

1) What sort of data are you gathering? and
2) What do you intend to do with it?

If you are not going to just try a bunch of options and see what works best, then you need to carefully consider those two questions.

StackExchange Database Administrators Q#19823, answer score: 3