What base to choose for a future project?

Question

PHP

Good day!
I came up with an interesting web project idea. I'm going to implement it in PHP. The question is in choosing a database, and perhaps you need to use several databases, I don’t know yet. I would like to know the opinion of experienced developers because I am a beginner and this will be my first complex project.
Why was the question of choosing a base? The fact is that you will need to store a lot of information, as well as quickly display it when prompted. In the first 3 months there will be no problems, but when the size of the database exceeds 20-40 GB, I can’t imagine what the request processing speed can be and what everything will need to do with it. I came to the conclusion that it would not be bad to take 2 MongoDB databases. Store data in one - it will be a huge collection of tens of GB, and the second base for storing various small information about users, etc. Please point me in the right direction if I'm wrong.

Answer 1

Structured information is easier to store and process in relational DBMS stores. In MongoDB, it is better to store documents as a unit of information each.