Question

for example i have table users, which have 3 fields:

id - login - password
---------------------
1  | john   |  *****
2  | jack   |  *****
3  | jane   |  *****

now i want that each user could have his own settings.
So, do i need to create three different tables, like

user_N_settings:

id |  key        | value
-------------------------
1  | save_data   | True

or i should create one big table for all users instead?

users_settings:

id     | key       |    value   |    user_id
---------------------------------------------
1      | save_data |   True     |        2
2      | some_opt  |   False    |        3

Answer 1

One table for all users. A table per user would be very wrong.