File or database?

Question

Node.js

When should you use a DBMS and when should you use a file?
Where is it more expedient to store a log of errors or actions, where to store monotonous data (for example, a list of digital keys that are erased after a sale), etc.?

Answer 1

The database is needed where there is really a lot of data and / or they need to be operated on.
Logs can be stored both in a file (by setting the rotation) and in the database. Simply because the data from the logs is rarely analyzed.
The keys for sale are stored in the database stupidly for accounting, so that each Vasya can be shown which keys he bought.
Well, the icing on the cake-db is a private type of files.

Answer 2

when the file search speed ceases to satisfy, then they take a database that can sort data out of the box and thereby speed up the search. only and everything.