Do I need to create an additional AI field id field if there is already another unique field?

Question

MySQL

Some people definitely recommend adding an auto-incrementing id field.
Why is it bad to create a primary index on a Cyrillic field?

Answer 1

An index on a text field will simply consume more resources than on a numeric one. Otherwise, if uniqueness of values ​​is guaranteed, then a textual primary key is perfectly acceptable.

Answer 2

In general, legs grow out of the need to have a unique field. If there is no significant one, then an artificial "uniquelizer" is introduced in the form of an auto-increment field. If the table already has something unique, artificial formation does not make much sense.

Answer 3

Why is it bad to create a primary index on a Cyrillic field?

Because many decades of experience of many architects show that the natural key eventually loses its uniqueness. Surrogate - no.