Review system for restaurants

I'm creating a DB for a small project which consists of having multiple restaurant and a user can leave a review (comment and rating) for that restaurant but just once.

My question is:

Which is better practice to do:

Should my table Review have just a composed primary key of UserId + RestaurantId ? Or should I create a primary key auto increment?

I think the composed primary key should be good as the user can only leave 1 review per restaurant but I'm not 100% sure...

Given the information, a compound primary key would work effectively as a point of reference and has several advantages over an automatically incrementing key.

While an unrelated automatically incrementing primary key does absolutely guarantee that the database will be normalised, with your program working as it should that will likely not be an issue anyway.

The main advantage of using a compound primary key is that the review information itself can more easily be accessed from the program. I assume UserID and RestaurantID are used elsewhere within the program and therefore can easily be found. The biggest problem of an automatically-incrementing primary key is that it is totally unrelated to any other information, apart from being that primary key. Without it, you can easily source any particular review from a user without any additional information.

Regardless, neither implementation is bad. If you struggle with the compound key, it is no great failure to implement an automatically incrementing primary key. All it means is that you're storing somewhat pointless integers (which could, if this database gets very large, have an impact on the filesize).