Is there a need for an unsigned integer id for a one to one relationship?

Question

MySQL

There is a table of users (users), there is a table with counter fields (user_counts)
users is the usual one like all
user_counts with fields: id, user_id, comments, likes, votes, notifications
UPD: user_id -- unique, there cannot be 2 user_counts records with the same user_id
I wonder how necessary an unsigned integer id is for the user_counts table, if all the selections / updates still occur by user_id? Perhaps it helps some internal operations of the database engine to run faster or can it be removed?

Answer 1

in this particular case, user_counts stores the aggregated values ​​of comments, likes, votes, notifications, and there is clearly no need for a surrogate key, because the user_id uniquely identifies the entry.
ps read what is a surrogate key, why is it needed.

Answer 2

This is a common practice when designing tables. There is a primary key and there is a foreign key. In this case, the user_id in the table. The primary key must always be "unique". If not ID, then what will you take as the uniqueness of all strings? Otherwise, you will have to take comments or Likes or votes or notifications or combinations of them. But where is the guarantee that 2 identical combinations will not come across, for example, from comments and notifications.? Yes, and put the key with the same comment xxx characters? ))
I hope I explained clearly)